Boral Roofing Frequently Asked Technical Questions

The questions listed are web inquiries from actual customers. They have been answered by Boral Roofing Technical Department. Also note that Boral Roofing Concrete Tile products were previously made under the Monier LifeTile brand and are historically named in this document for clarity.

Q: We built our house in 1987; used Monier red barrel tile made at the Tacoma plant. The tiles have lost most of their red color now. We are told that they can be coated or painted to once again present a beautiful red Spanish style roof. What coating do you recommend to us in this case?

A: The loss of color is not a warranted issue since our warranty covers all of the physical properties requirements but specifically excludes color. Fortunately, the strength and performance of the tiles are unaffected by this color loss. There are a number of treatments that are used to rejuvenate old concrete tile roofs and most of the good ones involved a multi-step process of cleaning, priming and coating. The high-grade acrylics that are applied as the color coat will typically carry an 8-10 year warranty and can be expected to last much longer.

Proper preparation and material selection is important when choosing to re-color a tile roof and it is recommended that an experienced professional be used in this process.

The four steps process includes:

1. Evaluation, repair any broken roof tile. 2. Clean metal flashing that carry water. 3. Power wash, or a use of a biodegradable fungicide concrete cleaner. A popular one is "Spray and Forget". 4. Application of a penetrating binder, color coat and possibly a sealer depending on the type of product chosen.

Q: I am about to have a new roof (Monier) installed and the roofing company does not use battens, instead they GLUE the tiles down. Is this proper?

A: It is a standard installation procedure to use polyurethane foam to adhere the tiles directly to the deck. This system produces better wind uplift resistance and fewer or no penetrations through the roof deck.

Q: I have a question on code compliance and insurance rebates for tiles roofs. I have been told that tile roofs do not qualify for insurance credits and I am better off installing an asphalt shingle roof. Section 2 deals with the roof covering. It provides three options, IE 1) meets current codes, 1994 SFBC or 2001 FBC; 2) does not meet codes; or 3) unknown. The problem arises that option 1 provides several standards for the roof covering to meet. One of the standards is for asphalt shingles per an ASTM standard; one is for discontinuous roof covering per the FBC TAS's and one for metal roofs. For the two TAS's that are referenced, one is for wind driven water penetration, TAS 100, and the other is for uplift, TAS 107. The problem arises in that the uplift requirements address asphalt shingles only. The form does not address uplift tests for other types of roof coverings.

The issue is that this appears to either be an error with the unintentional consequence of disallowing credits for concrete/clay tile type of roofs or an intentional attempt to discriminate against tile roofs without specifically stating that tile roofs do not comply with the credits.

A: This is a hot topic more to do with politics than anything else. It is just a matter of time before tile receives its due and is approved for tax credits.

The fact of the matter is that concrete tile roofs are more energy efficient than other products for a number of reasons not to mention inherently greener.

All concrete and clay tile used in Florida have to be tested for static uplift resistance as well as wind and rain resistance. This is how we achieve our product approvals. All of our products are tested accordingly.

Q: I inspected a Tejas Espana Mission Red tile roof with wind damage. I determined that zero nails were used on the entire roof. The tiles were laid on batten strips and some were adhered using mastic. I read the installation manual and can find no circumstance where a zero-nail installation is acceptable. Please confirm. Is it ever acceptable to install these tiles without nails?

A: You are correct. There has been some minor changes throughout the years with most codes, however all the codes did require that at a minimum, the tile within the 36 inch perimeter areas were always to be fastened, the balance of the roof area to be fastened was dictated by the slope, wind speed and category of the structure.

The guidelines for the attachment of clay and concrete roof tiles are contained in Tables 1A and 1B of the current TRI Installation Manual for Moderate Climate (ICC ESR 2015P). The fastening requirements for areas designated as having winds in excess of 100 mph basic wind speed are shown in Footnote 2 of those tables. Appendix B of the TRI Guide contains additional information that provides guidelines for meeting the requirements of IBC Section 1609.7.2.

The methods of attachment provided in these tables have proven to be effective in holding tiles in place during high wind events and it is left to the discretion of the local building official as to which methods will be required in their jurisdictions. In most cases, the building official will base his decision on historical evidence as to the effectiveness of the prevailing regional practice.

Q: I need a cut sheet that states it is okay to use a 2" Ring Shanked Nail for the Barcelona 900 series tile.

A: We do not have cut sheets that make this statement. The code requirement is for ring shank nails to attach the tile by penetrating into the batten or through the deck at least 3/4", whichever is less. On steep roofs and/or high wind areas, two fasteners per tile may be necessary. If the roof is in Florida, 3" nails are typically required.

Q: I have a MonierLifetile roof that was damaged by Hurricane Katrina. Not many tiles were broken and I found the replacement tiles in a Contractor's bone yard. The color of the tiles I found did not match so I painted with concrete paint. The paint faded and did not adhere to tile. Any suggestions on paint specs and process to match color or can I paint the whole roof?

A: There are a number of companies that specialize in recoating old tile roofs and most of them use high grade acrylic coatings that are very durable and are even available in new "cool roof" colors that effectively reduce the amount of heat that enters through the roof. Regardless of which product is used, proper and thorough surface preparation is required for this process to be effective long term. Most of the companies offer warranties.

Q: I read somewhere in your literature that the lap of your field tile is determined by taking the length of the tile, subtract 2", and then dividing the result by 2 to get the lap. Yet, in most other areas, it says to install a 3" min. head lap. Is there any other requirement than the 3" min.?

A: The typical headlap for mechanically fastened tile installation is 3 inches unless restricted by product design.

A 2 inch tile headlap may be utilized if a foam or mortar tile application is used along with the recommended sealed underlayment system.

Q: I'm ready to re-roof my flat tile, but answers from consultants and contractors don't seem right. I like the profile type tile but am concerned that the heavy rains we get in south Florida don't seem to be controlled satisfactorily. I like the closed valley but many roofs in my area don't seem to have the fluted profiles line up leaving large holes that are visible from the street. I would like to see nice clean matching shapes. I have noticed that roofs with the profile shaped tiles seem to have the joining of the roof slopes at the valley bottom edge of the roof blocked with metal fitted into the profile tile. Is this correct? Shouldn't there be an opening to let water out?

A: There are several installation options. The most common in South Florida incorporates the use of standard metal flashing which is sandwiched between layers of roofing felt as part of a sealed underlayment system. Therefore, there is less concern over water flowing under the tile as there are prefabricated weep-holes in the eave metal to allow this water to exit off the roof. It is virtually impossible to line up the medium and high profile tiles in a closed/mitered valley so that you do not see the voids caused by the ends of each cut tile. An open valley detail is the best option to avoid seeing these voids and although is not the choice of most contractors, it is code allowed in most areas. The voids would be closed off with mortar and pointed to a smooth finish. This is described and shown on page 98 and 99 of the FRSA Installation Guide which can be downloaded from our website at

Q: The FRSA Standards are stating the underlayment for your product is D-249 90# roll roofing with hot asphalt. Can I use Polystick TU Plus? It is an approved product by the local code, but not by MonierLifetile. What are the approved underlayment products?

A: 90 LB Roll roofing is only one option allowable by the FRSA. Most self-adhered underlayments (more commonly referred to as peel and sticks) are approved for mechanically fastened applications whereas there are less product offerings for self-adhered underlayments, such as the one you mention, for tile to foam applications.

We can also recommend our own self-adhered underlayment, Boral TileSeal, which is usable for either purpose. See the Miami-Dade product approval for Boral TileSeal.

Q: When repairing low profile tile on battens, do you cut the nail above the batten or pull it out. If you cut, will it back out and injure the new tile? And, if you pull out, how do you plug the hole under the batten?

A: You will find it difficult to remove the nail with the batten in place although this is sometimes possible by using a ripping bar if the surrounding tiles can be elevated enough and wedged during the repair process. If flashing cement/mastic can be squeezed down into the exposed hole in batten, then do so and insert replacement tile. This is typically not possible. Because of the inability to seal the nail hole at the deck, it is usually best to cut the nail flush with the top of batten and insert a new tile using an approved adhesive at the tile lap. It may be necessary to remove the batten anchor lugs in order to achieve this. Nail back-outs do not normally occur once the existing fastener has penetrated the batten and deck.

Q: Can the Madera tile be used when there is a rain water collection system that collects roof run-off water for irrigation purposes?

A: Madera is a concrete tile made from the same basic materials as all of our concrete tile products. Therefore, it can be used to help run maximum water off the roof. Care should be taken to use green friendly flashings like our Wakaflex product (not lead ) to help keep the water on top of the tile.

Q: I installed Lifetile with a slurry terra cotta color on my home in 1993. I did it myself. The color is still performing well and the roof has never leaked. I'm thinking about the benefits of a cool roof. Can I make a slurry coat of white cement to change the color instead of painting? It seems in the Fort Lauderdale area people who paint roof tile have to do it every 3 years. If a slurry coat is a good idea can you recommend instructions?

A: The slurry coat is a factory applied cementitious coating that we do not produce for jobsite recoating procedures.

The best solution is to lightly clean your roof and apply a good quality acrylic tint sealer (such as ATS-13 manufactured by Pompano Paints ).

If the coating has broken away or is loose at the surface, an alkyd type conditioning primer may be used prior to sealer application.

Q: Do you have any shop drawings for attaching tile in high wind areas?

A: You can find drawings and attachment resistance charts in the FRSA Installation Manual. This is available on our website at

Q: What is the language used to measure concrete roof tiles?

A: Roofs are measured in squares. A roofing square is equal to 100 square feet. There will be varying amounts of tile per square dependent on the size of the tile. Tiles are typically ordered by the square.

Q: I am interested in the Villa 600 and the Espana 600 roofing tile. I was wondering if these products qualify for the government Energy Star tax credit. I did notice that they were "cool tiles" but wasn't sure if they met the Energy Star rating standards.

A: Although there are concrete tile listings on the ENERGY STAR directory, the rebate does not currently apply to concrete tile roofing. The rebate qualification specifically lists metal and asphalt shingle roofs. This is unfortunate, considering the benefits of concrete tile that far exceed other roofing materials – durability, high thermal mass (reduces peak energy demand), carbon re-absorption, aesthetics and Boral Roofing’s Energy Efficient Roof system which provides a 50% reduction in the amount of heat penetrating the conditioned space versus direct-to-deck installations and a 22% reduction in energy consumption.

Q: We live in a condo in Florida with MonierLifetile roofs and would like to know how often you recommend power washing the roofs?

A: The frequency of cleaning is dependent on how dirty the roofs get along with how much vegetation and moisture content is in your community. With that said, it's typically every 2 to 5 years in Florida. The key is to clean before the roofs get too dirty; that way the minimum pressure is required thereby keeping the surface of your roof tile in better condition over the years. The pressure should be no more than 1200 psi. A light chlorine solution may be applied to the roof first to help remove the mildew and algae. An option is to then apply a clear sealer to help protect the surface and maintain the color.

Q: We are replacing our 40 year old white flat concrete tile roof with a Vanguard Roll Athenian Blend cool tile. Our contractor has suggested that a sealed tile will better resist mildew. Is the Athenian Blend a sealed tile? The tiles will be fixed to the deck using a foam adhesive. Will a sealed tile stop the tile from breathing and have a detrimental effect on the tar papers underneath?

A: The Athenian Blend is a sealed product and the system by which it is installed will still allow the sub-roof (below the tile) to breathe and help create enough airflow to keep the underlayment in good shape. The white tile will give you more reflectivity and a FPL rebate providing that your roofer is a participating contractor with FPL.

Q: Regarding fire ember control on the ventilated roof: Is the air channel fully fire resistant? What happens when super heated air comes at the roof line?

A: The most important thing you can do to protect your home from wildfires is what Fire Marshals like to refer to as "hardening your structure". This means, redesigning your home to prevent burning embers from penetrating through the exterior of the house. Concrete roof tile is the best fire-proof roofing material because concrete doesn't ignite. The next most important thing is to replace conventional vents with fire resistant vents, which allow air flow, but block direct flames and embers from penetrating through the vent during a fire. The next most important thing to consider is to make sure you have tight fitting metal eave closures that close off the front of the tiles at the eave. They should not have large gaps that could allow large burning embers to enter the system and land on the asphalt saturated felt under the tiles. The lack of proper eave closures was found to be one of the main failure points of the San Diego fires a few years ago. In the Freeway Complex fire of Yorba Linda and Anaheim Hills recently, the major cause of home destruction was caused by embers entering through vents and burning the structures from the inside. Superheated air is also blocked by fire resistant vents, which act as a heat sink, by preventing the air flow from directly flowing into the interior of the house and instead must follow a labyrinth maze to get through the vent, robbing the air of the majority of its heat in the process. Again, the most important thing to remember is to harden your structure to prevent those embers from igniting on or inside the home.

Q: We had the Homestead tile installed several years ago and I was wondering about the method of installation. Should the tile be a full overlay, meaning one directly above another or should they be stagger from row to row?

A: There are no instructions regarding vertical alignment (half-bond, or straight) of flat tile unless individual manufacturers state otherwise. In essence, a roofer can install flat tiles in any manner he chooses, including straight bond, although the aesthetics would almost certainly be affected. With the advent of split face tiles, a roofer must likewise be mindful of the straight line affect that can result from a half bond application of those tiles. Vertical lines may be marked prior to the installation of tiles to help prevent the lines from wondering side to side.

The straight bond method is recommended for all tiles, however a half-bond look is desired esthetically and is considered a choice between the home owner and the roofing contractor to discuss. When a flat profile such as homestead is installed starting with a full piece at the right downward first row followed by the installation of the second row directly above the first roof tile, a half piece generally 6 inches wide follows. Special consideration is required when fastening the roof tiles so that the fastener is not protruding upward enough to engage the tile above as this will cause a point load break on the tile either in the middle, or at the lower right side of the under-lock portion of the roof tile.

Both straight and half bond are considered acceptable and are within guidelines of the Tile Roofing Institute.

Q: I would like more technical information on your Boral Tile Seal Underlayment and need to know where I can get the application specs. Is this product approved in Broward County? Is this product better than hot mopping a 90 lb. felt over the tin tab applied felt? Should the edges be sealed with black mastic for better application?

A: Boral TileSeal has a Miami-Dade Notice of Acceptance (NOA) No. 08-0107.02 for use in Dade and Broward Counties, provided that an approved base sheet is also used. Other jurisdictions may allow MLT Tile Seal to be applied directly to the roof sheathing. Installation instructions are available by requesting MLT Component Sheet AC 542. This can be obtained through our Customer Service Department. The material is a modified asphalt and can therefore be considered an upgrade to a No. 90 (30/90 hot mop) cap sheet. The side laps (not the head laps) of the material can be sealed with a compatible modified adhesive. This is true of most SBS modified underlayments.

Q: I would like some information on the best way to clear my roof valleys. Debris has collected under the tiles and I would like to dislodge it before the water runoff is inhibited and causes leaks.

A: Debris accumulation in the valley areas of a roof is a fairly common occurrence that does not always lead to an immediate problem but it is certainly something that should be evaluated before it becomes problematic.

In most countries, it is common practice to keep the tiles cut well away from the center of the valleys to allow rain to flush out debris before it accumulates. In the U.S. however, the narrow cut or closed valleys are more common so the need for periodic cleaning becomes an issue.

If the debris has become trapped beneath the tiles, it will be necessary to temporarily remove the tiles for effective cleaning. The next step is to evaluate the method of application to make sure that the battens or the tiles are not contributing to the trapping of debris or diversion of water flow. If either the battens or tiles are blocking water flow in the valleys, it is recommended that batten extenders be installed prior to the replacement of the tiles. This may be done whether the tiles are cut close to the center of the valley or if they are cut open.

Q: We are considering replacing our wood shake roof with Cedarlite. Is it required to cover the existing skip sheeting with solid sheeting?

A: Cedarlite tile, despite its similar appearance to wood shake, is a completely different type of product that cannot be installed in the same manner as shakes. Wood shakes are double-lapped products that are 24-inches long with only 10-inches exposed. Cedarlite is a 13.5-inch long tile with only a 3-inch headlap. Consequently, our building codes require that an underlayment be applied beneath the tiles.

There is a provision that would allow the tiles to be installed over spaced sheathing but that method requires a very specific application and special type of underlayment that is not readily available in this country. While this method may be used, most contractors are not familiar with this application and many feel that it is more economical to sheath the roof and install the tiles in the more traditional method used in this country. The other issue is that many municipalities do not allow the spaced sheathing method of application.

Q: We recently noticed that on the peak of the roof, one of the tiles is cracked and the pieces are separated by about one-half inch. Are there any repair procedures for the broken tile, or does the tile have to be replaced? In either case, can you provide a suggested repair procedure?

A: While adhesives may be used for short-term repair of broken tiles, it is generally recommended that tiles broken in the manner that you described be replaced. If the tile you are replacing is a ridge trim they are typically joined to the overlapping tiles with an adhesive and you will have to break the bond between these tiles to allow a new tile to be inserted. The easiest way to do this is usually to further break the broken tile and then use a chisel to separate the bonded pieces. Once all pieces of the broken tile have been removed, it is allowable to insert the replacement tile and join it together with both adjacent tiles with adhesive placed in a location and of sufficient quantity to ensure a good bond between the tiles.

Q: Is it ever a necessity to change the underlayment of a tile roof? The tile has a long life but what about the underlayment? I live in a condo complex and they are considering replacing the underlayment of about 18 years but this obviously is a very expensive procedure. Is this typical in the desert?

A: The underlayment beneath the tile may require replacement in the event that it no longer serves the purpose that it was designed for. There can be any number of reasons for this premature failure, ranging from prolonged exposure prior to tile installation to poor workmanship.

The underlayment is intended as the back-up system for the tile and, as such, only comes into play when water finds its way beneath the tile. Since you are faced with this task of reworking the roof, I would suggest that you select a good quality underlayment but make sure that the tiles are installed in such a manner that water does not easily get underneath the tile.

Q: What is the recommended roof truss spacing and the sheathing thickness for standard weight roof tile on a home to be built in northwest Florida?

A: Florida has very high live load requirements. In most cases a few extra pounds of roof covering makes no difference in the truss design. Standard Florida residential truss spacing is 24 inches O.C. using engineered trusses.

Q: I'm installing tile on a new home in Boise, Idaho. Would you recommend the counter batten installation system? What benefits would you expect? How do I have to deal with the increased gap at the eaves/rake-area?

A: Since the Boise area is a more moderate climate region than other parts of Idaho, it is not essential that a counter-batten system be employed but it nonetheless can offer some advantages for the long-term performance of your roof system that you may still want to consider. In regards to the extra space created by the elevated batten system, MonierLifetile has created special eave components that are designed specifically for these systems so the appearance and performance are not impacted.

Q: I have a client in Boca Raton, FL who has a 10 year old "S" concrete tile that was mechanically fastened over a 30/90 underlayment on a 4/12 pitch. He thinks the hurricane wind may have loosened his tiles. Some of the butts can be lifted up 1" and some up to 2". What is acceptable tolerance? There are no leaks and only the ridge tiles came off. Does he need a new roof?

A: First of all, there is always some movement of the nose on a mechanically fastened system. This is desirable. It allows some movement when walked on and avoids stress on the tile and minimizes foot traffic breakage.

A 1-inch movement at the nose would not be a concern. A 2-inch movement is not good. That level of movement is considered failure in our static uplift tests. Having said that, it is one thing to have a large percentage of the roof with excessive movement as opposed to just a few tiles.

Of course, any decision to repair or replace a roof tile installation should be made by a certified roofing consultant that has been on the roof and inspected it. From what you've described, it does not seem that a reroof is necessary. Some repairs on a few obviously loose tiles are probably all that is required.

Q: Do you have a detail for the tile installation in Maui County or Honolulu? I understand they like a space under the tile for air circulation.

A: The concept of circulating air between the tile and the roof deck is not unique to Hawaii but Hawaii adopted the universal system of counter batten application many years ago due to the strong New Zealand influence when that market was developed. MonierLifetile has an Energy Efficient Roof that features an elevated batten system and other components that provide enhanced ventilation and drainage beneath the tiles.

Q: Are there any techniques to make sure that a eyebrow dormer lays flat on a roof being tiled with S-shaped Mediterranean tile?

A: Aside from making sure that the dormer is positioned in a level manner, the fit of these dormers depends largely on the type of apron flashing provided at the front edge. Lead or dead soft aluminum aprons are the most common but if rigid steel is used, then the void beneath the flashing must be filled with mortar or some other type of fitted closure material. MonierLifetile also offers a flexible flashing material called Wakaflex that may also be used to weatherproof difficult transition or flashing requirements.

Q: When we bought our home in 2002 we were told that if we removed more than one tile from our roof that our warranty would be voided. We had one solar tube installed and would like to install another one, but would like to know if our warranty would be voided?

A: The product warranty provided by MonierLifetile applies only to the actual roof tiles and would be unaffected by the installation of integrated components into the roof. The warranty that you are referring to is most likely the installation warranty provided by the builder or roofing contractor that relates to the installation and performance which is totally independent from the MonierLifetile product warranty.

Q: The edge tiles on my roof are not well attached. They have two pre-punched holes in them, but the contractor nailed only on the side that contacts the wood. What size masonry bit should I use to clean out the other hole and drill into the field? Is there any other way to fix this problem?

A: The trim tile comes with two nail holes along each side of the trim so that the same piece can be used at either end of the roof. As long as the trim is installed with two sufficient length nails into the wood, they are installed to code.

Q: Do you have any product approvals for Barcelona 900 tile installation on a sloped concrete deck?

A: There are no formal specifications for concrete deck installations, but they are being done on a job-by-job basis.

Option #1: Prime the concrete deck and hot mop a No. 30 base sheet. Hot mop a No. 90. Back nail the No. 90 with concrete fasteners (pre-drilled). Foam apply the tile.

Option #2: The same anchor sheet installation as Option #1 with a hot-mopped SBS modified cap sheet. Foam apply the tile.

Option # 3: Prime the concrete deck and apply Boral Tile Seal self-adhered underlayment making certain of sufficient bonding by using a light roller or stiff broom. Most code bodies also require attachment of the top of each sheet into the substrate. Foam apply the tile.

Note: There is test data that would allow a self-adhered membrane directly to the concrete deck without an anchor sheet; Miami-Dade would require an engineer's approval on such a system.

Q: A roofing contractor advised that chips along the edges of installed tile are routine. Do you have any guidance on what number of tile and size of chips you would consider acceptable in installation of your product?

A: Any slurry coated tile could have some chips at the nose. This is an aesthetic issue and as such is subjective. Small chips can be painted to match the base color of the tile.

From a functional perspective, any chip larger than 2 inches may compromise the water shedding capability of the product. Even this is not really an issue because the tile is applied over a sealed underlayment that is designed to handle water runoff. Having said that, large pieces of missing chips can be unsightly and should be replaced.

Q: Is there a "cap" design for a mansard condition using the flat profile concrete roof tile?

A: The easiest way to cap a mansard application is with a metal cap unless the wall is narrow enough to be fully covered by one of our standard ridge tiles.

Q: What would you recommend in lieu of copper flashings at roof in a marine exposure environment?

A: If your project is situated within 1500 feet of the shoreline, you should use copper or stainless steel for your exposed flashings. If you are further than that, you could probably use a Zinc-Alum or Galv-Alum material for your flashings and save quite a lot of money without sacrificing too much corrosion resistance.

Q: How concerned should I be about pest control workers breaking tiles when tenting the house?

A: Our experience has been that pest control companies who utilize the tenting method of termite control typically pay very little attention to the protection of the roof and in fact ask you to sign a waiver releasing them from any responsibility for broken tiles. I would suggest that you look for a company that features one of the newer methods of cryogenics or orange oil for your termite treatments.

Q: How concerned should I be about the tile surface appearing cloudy as concrete bleeds?

A: You are most likely referring to the efflorescence that can sometimes occur with concrete products. While it is impossible to guarantee against efflorescence, we do apply a sealer to the surface of our tiles during the manufacturing process that is designed to limit and control this occurrence. Natural weathering will eventually remove this condition.

Q: The oxide that my builder placed on my new roof does not match the roof tile color. What can be done to correct this situation?

A: This can be one of two things: Either the mortar work is going through the efflorescence phase of the curing cycle (white film on the surface), or the oxide is the wrong color. If it is efflorescence it is temporary. You can determine the condition if you simply dampen a section. This will temporarily remove the white film and reveal the actual color. Time will clear up efflorescence. If it really is the wrong color, a 100% acrylic paint will provide a good match and is an enduring solution.

Q: Is there a manufacturer's requirement to cut back roof tiles at valleys?

A: Tiles may be cut to form either an open or closed valley. The only requirement is that when flat tiles are cut to a closed valley, (when using a top flashing method) the roofer must use a ribbed valley or batten extenders. This requirement went into effect as of July 1, 2006.

Q: What are the advantages of Cedarlite vs. Madera? I know Cedarlite is lighter. Is it less durable? Less fire resistant?

A: Madera is a mid-weight version of the popular Cedarlite tile that provides a stronger, less expensive solution that looks almost identical to Cedarlite. Both tiles have similar fire resistance and long life expectancy but the Madera tiles will handle foot traffic, hail impact and sliding snow better. Where the roof structure is not adequate and cannot be reinforced to support standard weight tiles, Cedarlite is the preferred solution.

Q: I am contemplating installing your Cedarlite product on my home which currently has wood shake. Is this a project a handy homeowner can take on? I have built barns, roofed sheet metal barns and cabins, and done asphalt shingling. Some specific questions: How do you cut the tiles? Do you have to paint the cut edges if you don't want rake tiles? Is there a time limit from receipt of tile to installation? I am installing on a 2" X 6" T&G roof deck and I don't want to use battens. What would be the best underlayment material?

A: While the installation if a tile roof is not overly complex, it is best accomplished with a methodical approach that could easily be done by a handy homeowner. The most difficult part is the coordination of the project and the delivery and loading of the tiles. You should check with your local roofing supply house to see if they offer roof loading services. Beyond that, if you follow the installation instructions, it is not difficult to install the roof.

As to your specific questions: You cut the tiles with a diamond blade that can be used on a standard hand-held power saw. Wear a mask and goggles to protect from cut dust and clean the dust off of the tiles at the end of each day. An alternative method of cutting concrete roof tiles is with a product called Hytile. - You may paint the edges of the cut tiles, but it is not necessary as they will eventually match the rest of the roof as the surface sealer wears away. -Concrete tiles never become too brittle to install. -While there are a number of good underlayments available, if you are intending to fasten the tiles directly to the roof deck, the best alternative is a self-sealing, self-adhered product, such as Boral Tile Seal.

Q: What is your UL Fire Rating?

A: Concrete roof tile is considered a Class A fire rated product by all local code jurisdictions. MonierLifetile and most other concrete roof tile manufacturers use ASTM E 108, a fire brand test in lieu of UL. Our compliance is verified by merit of ICC Evaluation Report 1647. Historically, our tiles have been tested to UBC 15-2 which is essentially identical to ASTM E108 and UL 790. All three tests may be used to determine the fire classification for roofing products, as required by code.

Q: I have a Monierlifetile roof and I need to paint some of the tiles. Sherwin Williams is recommending H&C Silicone Acrylic Concrete Sealer. It is xylene based and I need to know whether it will be compatible with the finish on your tiles.

A: Xylene based sealers have been used in the past as a coating for concrete roof tile. The material must be handled with care. It would be better to use a less toxic, 100% acrylic based sealer with a slight tint for color blending.

Q: I want to install Barcelona 900 tile over 3X4 perlins (no plywood or paper) on an outdoor loggia. If we space the perlins to the nailing of the tiles, is there anything else we need to do? The structural engineer and the county have approved this application. We understand that we will get some leaking, and that is OK. The owner wants the old world look of seeing the bottom of the tiles.

A: Many people choose to use our tiles in a decorative mode and we have no problem with that as long as the performance limitation is recognized as you apparently have.

Q: We are doing a tile roof in Fort Lauderdale. What are the dry-in requirements?

A: The minimum dry-in in Miami-Dade and Broward Counties is a No. 30 organic felt. There are upgrades that are permissible.

The standard underlayment system used in those counties is a 30/90 hot mop system. Also used is a No. 30 dry-in with a self-adhered membrane as a cap sheet.

Q: I have re-roofed my home with your tile and in the next days will have my final inspection. What should I look for, as a homeowner, to check the quality of workmanship of my roofing contractor? The roof has passed the county's wind strength requirements but I am uncertain as to the level of workmanship that I should expect. For example, should the tiles be in a perfect straight line?

A: Aesthetic issues should be discussed with your roofing contractor. Please keep in mind that roof tile is not bathroom tile. It is a dimensional roof covering that is intended to be a natural blend of small, individual components. Some trust in the roofing contractor is required, because you cannot see under the tile once it is finished.

Q: We have a Tudor style home and have ordered Cedarlite tile. The roofer is not planning to use battens in the installation. Is it optional or do you recommend battens in the installation? What is the advantage or purpose of battens?

A: All of our tiles, including Cedarlite may be installed on battens or fastened directly to the roof deck. The Cedarlite and Madera tiles are unique in that they do not feature a projecting anchor lug by which most of our other tiles would normally attach to the battens.

While nailing the tile directly to the roof deck is fine and would perform just as well as a tile nailed directly to a batten, you may want to consider the option of installing the tile to an elevated batten system.

By installing a counter batten or elevated batten system, you effectively raise the tile and the batten above the roof deck. This method does two things that can have a dramatic effect on the performance of the roof. Firstly, it provides for better drainage should water get beneath the tile. Secondly, more importantly, the increased air flow created by this system has been proven to be a very effective method of ventilation between the tile and the roof deck. This airspace has been shown to be effective in reducing the amount of heat that can enter through the roof and into the structure, thereby reducing the amount of energy needed to cool the house during hot weather.

Q: Can tile manufactured in Florida or Texas be used in our northern climate in Minnesota?

A: The MonierLifetile color-through tiles pass freeze/thaw testing for code purposes and can be used in all climates. We do not recommend slurry coated tiles in northern climates, however.

Q: Does your warranty require the installer to use your Boral TileSeal? And, how long can the roofer allow underlayments to remain exposed before installing tiles? Does this affect the warranty?

A: 1) Boral does not require the installation of Boral Tile Seal as a condition in supporting our product warranty.

2) The Boral Tile Seal can be exposed for 6 months. The warranty does not apply to Boral Tile Seal, as mentioned. If an underlayment is exposed longer than the recommended time, it should be examined by the manufacturer or one of their representatives.

3) The Boral Tile Seal underlayment carries a separate warranty of 25 years.

Q: Can you recommend a brand of paint to cover faded roof tiles?

A: After cleaning the tiles, you can use a good quality 100% acrylic paint.

Q: Are battens used with Madera?

A: Madera tile, like all tiles, may indeed be installed on battens or direct to the deck. As as a matter of good practice, we recommend that they be installed on our 1"x3" Elevated Batten System that was originally developed specifically for this product line.

Q: Do you have installation instructions on how to create a turret with Barcelona 900 tile?

A: Interlocking roof tiles are not ideally suited for installation of turrets but there are ways to do it if enough time and preparation are applied. There is no precise formula for turret application. As far as material usage, you will definitely need more tile since the coverage of each tile will be diminished by the increased sidelaps and cut work. You should anticipate that you will need 2-3 times the amount of tile that would normally be required for this size roof area.

Q: I want the staggered roofing placement of my tiles. Can this be done with Madera?

A: The Madera tiles are not designed to be applied in a staggered fashion but we have received numerous reports of this being done and have noted that it results in a very unique look. The one precaution that we provide to roofers who elect to install the Madera or Cedarlite tiles in this manner is the fact that there is a small water stop at the top of the underlock of the tile that should be removed on the lapped tile to prevent this stop from lifting the adjacent tile and presenting a point load and potential water intrusion problem.

Staggered tile courses are usually only considered for steep slope roofs since the effect is not as noticeable at lower roof slopes and most people do not wish to spend the extra money that this application requires if they are not going to be able to see the effect. The aforementioned precaution becomes less critical as the roof slope increases since foot traffic that could create point load is less likely on roofs that are too steep for walking. Likewise, water intrusion is less likely on steep slopes since water exits the roof so quickly that it typically doesn't have much of a chance to be diverted sideways.

If you do want to pursue this application you should know that it will require that you order more tile (approximately 5-10% more per inch of stagger) and will weigh slightly more (again- 5-10% per inch of stagger).

Q: My company is currently in the initial construction stage for two seven story condominium projects. The buildings were both designed with tile roofs but some of the purchasers are suggesting that standing seam metal is a better material in the event of a hurricane. Could you provide any information to back up the use of tile?

A: Metal roofs did perform well during recent hurricanes. When failure did occur, entire sections were affected (came loose or blew off). Roof tile also did well when installed correctly. Impact damage (flying debris) to metal roof coverings results in dents. Impact damage to tile roofs results in limited breakage that can be repaired. Aesthetically, there is general agreement that tile roofs are the roof covering of choice by most owners and builders.

Q: I had the Monier Duralite roofing tile installed about 12 years ago. The grey colored tile has slowly lost its glaze through the years and now has a greyish brown appearance. When installed, I was advised this tile has a lifetime warranty. Having such a long warranty, why is the tile so discolored and have such a dirty appearance?

A: Our product warranty applies only to the physical properties of the roof tile and not to the appearance. Different climate conditions can affect the tiles differently so the dirty appearance could easily be the result of dirt accumulation on the roof or even moss or algae that forms on the roof in many climates. The shine that may have been on your tile when they were first purchased was not a "glaze" but rather a temporary surface sealer that is applied to the tile during the manufacturing process to prevent efflorescence from forming on the tiles. This risk of efflorescence only affects the tiles for the first few years so the sealer is designed to gradually wear away to leave a more natural matte appearance.

Q: What can be done about bats getting under the curved tiles at the edge of the roof?

A: Any opening in the roof can provide an opportunity for bird or animal nesting. For problem intrusions such as this, I would start by contacting an extermination or pest control company since they undoubtedly would have some experience with such things. The method used for closing off the openings would depend largely on the desired aesthetics. Many openings on tile roofs are closed with mortar or polyurethane foam although wood trim may also provide an effective barrier as well. A great alternative to the above mentioned temporary solution is MonierLifetile's Wakaflex, a rollable and paintable flashing which is installed between wall and concrete roof tiles. It carries a 25 year warranty.

Q: How do you install nailer board used to attach the hip and ridge trim tiles? Do you wrap with a weather protection or a tile guard or put mortar without the tile guard?

A: If mortar is being used as weather blocking, the wood must be protected from the mortar by installing a moisture barrier between the mortar and the wood. This is typically accomplished by inserting a layer of roofing underlayment over the wood prior to the mortar application.

Q: We have a Monier tile roof on our home in Hawaii, installed in 1974, and we would like to change the color. Is there a paint or coating you recommend?

A: There are a number of companies that specialize in recoating old tile roofs and most of them use high grade acrylic coatings that are very durable and are even available in new "cool roof" colors that effectively reduce the amount of heat that enters through the roof. Regardless of which product is used, proper and thorough surface preparation is required for this process to be effective long term. Most of the companies offer warranties.

Q: Do Boral Roofing products have an Energy Star rating?

A: Boral Roofing has been actively participating in the studies that are being conducted by Lawrence Berkeley and Oakridge National Laboratories to determine the best ways to make roof systems more energy efficient. These studies evaluate Cool Roof performance under the auspices of the California Energy Commission.

While we have evaluated a number of our tiles to the Energy Star standard, we feel that the California Cool Roof Council (CCRC), which demands a 40% reflectivity and .75 emissivity is far more useful than the Energy Star level of 25%. Since Energy Star is currently re-evaluating their test standards, we have submitted some recent test results from Oakridge (ORNL) for their consideration as additional criteria for people interested in reducing their energy usage.

In short, the latest testing proves that tile roofs offer advantages far greater than can be achieved with just reflective coatings and emissivity ratings. In fact, the study indicates that the vented air space between the roof deck and the installed tile effectively reduces the amount of heat that enters the roof of a building by an amount that's equal to roughly 30 points of reflectivity. Clearly, this effect makes Cool Roofs far more accessible than the past reliance on special coatings and colors.

What this means to you (if you are in the process of preparing an upgrade of your current roof) is that you may maximize your results by taking whichever tile you choose (lighter colors have highest reflectivity) and installing them on an elevated batten system that allows for enhanced airflow beneath the tile. Vented eave riser metals and ventilated ridge tapes are additional components that factor into this new breathable roof that should maximize your energy savings from your roof.

If you want only to have a reflective roof, there are companies that specialize in spraying new, highly reflective coatings onto older tile roofs.

Q: I recently had a renovation done where a rubber / membrane roof was installed on the dormer because of the low pitch. In the winter snow builds up with a small layer of ice next to roof. Then it slowly slides to the edge where it falls off in an avalanche. My contractor said that if I used snow guards it may cause ice dams which would be worse. Is that true? What type of snow guard can I attach to a rubber roof?

A: Specific solutions to snow retention problems vary. The following is recommended for this particular case. Apparently, the roof slope is low enough to require a sealed membrane but not shallow enough to retain the snow pack. Certainly, snow retention would seem to be a viable solution but I'm unsure why your contractor would be concerned about ice dams since these conditions are not necessarily related.

Typically, ice dams are created when there is heat loss from within the structure that is sufficient to melt the standing snow which in turn, runs down the roof until is hits the overhang of the roof that is usually much colder which causes the snow melt to then freeze and gradually build up into an ice dam. This can be exhibited most commonly by the icicles that hang from your roof eaves.

From your description, it is not clear to me if you, in fact, do have the conditions that would result in ice damming but you certainly seem to have a situation that leads to avalanching which can be dangerous. I am not familiar with any snow retention devices that are designed to be installed on stand-alone sealed systems since all we deal with are concrete roof tiles.

In any case, I cannot see where snow retention would result in ice damming. The thin layer of ice that forms between the snow and the roofing material is quite common and in many cases will form a bond between the roof and snow pack. Unfortunately, when the first warm weather comes, this bond can break and result in the sliding that you have experienced.

Q: What is the maximum slope for tile installation on a roof?

A: Tiles may be installed on any roof slope but, on slopes exceeding 24:12(200%), the nose ends of all tiles must be securely fastened. This is typically accomplished with special clips and/or adhesives.

Q: Have any of your roofing products been tested to UL 2218?

A: The UL 2218 is a convenient standard that basically consists of the dropping of steel balls onto roofing materials to compare impact resistance. While this is a fairly simple test, the tile roof industry did not feel that it effectively portrayed hail stone impact. For that reason we chose a more appropriate test (now known as FM 4473) that actually simulates hail impact by utilizing an ice ball cannon. The results of this test are what we used as basis for our hail warranty. In 2004 an industry-wide test for concrete tile was conducted using the factory Mutual (FM) 4473 testing methodology, a significant improvement in replacing the actual effects of hail on roof tile. This test requires that each tile is impacted in 3 different locations by ice ball ranging from 1-1/4" to 2" in size. The ice balls are shot at terminal velocity and each tile tested to withstand 6 hits each. To successfully complete the test, the tiles has to withstand the hits without breaking the tile (or showing any visible crakes), using the different sized ice balls for each test. MonierLifetile's concrete roof tiles products are synonymous with enduring protection from the elements in all climates. Now, with the recent certification through the Roof Covering Impact Certification program sponsored by Architectural Testing and recognition from State Farm Insurance, homeowners will now qualify for insurance reductions when choosing a certified product from Boral Roofing after June, 2005.

Q: Can we use an existing EPDM membrane (5:12 pitch) for substrate in Minnesota?

A: Although EPDM is not normally installed beneath concrete tile, there is no reason that it cannot be used. It is important however, when using a sealed system, to provide adequate ventilation to avoid condensation problems. The use of a counter batten system is also important in climates with severe weather. However, consideration should be given to the sealability of the specific EPDM around roof penetrations.

Q: Can I use your products on a roof with pitch less than 4:12? I have a 40 year old house with 2X4 rafters 24"o.c.

A: Tiles may be installed below a 4:12 slope but special consideration must be made for the selection and application of the underlayment at the lower roof slopes. Also, it is recommended that for mechanically fastened systems, that a counter batten or elevated batten system be used at lower slopes. The engineering requirements depend on the policies of your local building official. In most cases, an engineering report verifying the capabilities of the structure will be required. The size of the rafters are not as important as the type and frequency of supports and ties. Most roofs are capable of supporting our lightweight tiles without enhancement, but if standard weight tiles are used, some reinforcement may be necessary. 2x4's are commonly used in the current pre-fabricated trusses that support tile roofs on new homes but when 2x4's were used in roofs forty years ago, it was usually for relatively short spans or on steeper roof slopes. As a rule, 2x4's on 24"o.c. should not span much more than 7 feet without support.

Q: Will my room with a cathedral ceiling support your lightweight tile?

A: Tiles are commonly installed over cathedral ceilings and our lightweight tiles are typically considered a viable alternative if you are replacing an existing roof. The specific capability of your roof system must be determined by the span of the rafters and the size and spacing of the rafters. Generally, when large spans are designed the engineer or architect will increase the lumber size. The engineering requirements depend on the policies of your local building official. In most cases, an engineering report verifying the capabilities of the structure will be required.

Q: I am currently in escrow on a house that has the Monier roof tile. The tiles on the main roof of the house are attached to the roof joists directly, with no tar paper, or felt, or anything between them and the wood. Is this correct installation, or not recommended, or possibly not even to code.

A: The open spaced sheathing method of tile installation is fairly common in some parts of the world but was only practiced for a short while in this country. This method was code approved up to about thirty years ago, after which time, this type of application required that a special underlayment be used with the installation. That being said, when properly applied, this type of installation can perform very well for many years.

Q: We live in an area where moss on roofs is prevalent. How does your roofing material hold up under wet, damp conditions and what precautions need to be taken to prevent moss build-up?

A: Our tiles hold up very well in the type of climate that you described but, unfortunately, we can offer no magic solution for avoiding the growth of moss on the roof. The good news is that there is no indication that moss or algae do any harm to the concrete tiles themselves. Small amounts of moss on a roof are not a problem but, left unchecked, moss will continue to grow and may eventually block and divert water flow, thus diminishing the watershedding capacity of the roof. Periodic cleaning of the roof can prevent this and the use of biocides or zinc strips may be incorporated to slow the growth of these organisms.

Q: My home was built in 1938. All the rafters are 2x4 construction spaced 24 inches o.c. Is your Duralite product acceptable for a reroof on this house?

A: Our lightweight tiles are designed as reroof options for houses that were not originally designed for standard weight tile. In most cases, no additional reinforcement is required for Boral lightweight tiles although it is still important to consider the condition of the structure. On a house as old as yours, there are sometimes changes that have been made to the structure and these need to be identified and analyzed to certify their compliance to standards. Rafter sizes of 2"x4" on 24" centers is quite common for homes built at that time and they would be capable of supporting a tile roof if they are properly supported and attached. Current allowable, unsupported spans for 2"x4" at 24"o.c. would not exceed 7'9" for lightweight tile or 7' for standard weight. Your building official will likely want to know the rafter spans and other information prior to issuance of a roofing permit.

Q: When installing the roof ridge tile, what is the minimum overlap between the tiles?

A: Ridge tiles must be lapped sufficiently to cover the nail holding the preceding tile. This nail hole must be sealed with roofing cement or other adhesive that will effectively seal the nail hole and provide a firm bond between the two tiles. The lap is typically a minimum of 2 inches.

Q: We are planning to install your tile on a dome roof with varying pitches from approx. 12:12 to 2:12. What kind of special precautions should be used to prevent wind driven rain from penetrating the system of the lower slopes?

A: It is difficult to totally prevent the entry of wind driven rain into low slope roofs but there are steps that may be taken to guard against leakage and roof damage. Increasing the head lap of the tiles installed at low roof slopes can be helpful in preventing water intrusion but steps must still be taken to prevent damage beneath the tiles. On slopes below 3:12, a sealed underlayment is required and a counter batten or the Boral Roofing's elevated batten system is required by code to keep the battens and tile above the roof deck to prevent damming and minimize fastener penetrations.

Q: What is the thermal resistance "R" value for your Shake style roof tile?

A: We do not publish or promote the "R" values of our tiles due to the large number of variables that may affect this figure. I can tell you that ASHRAE has published figures that put a concrete tile roof assembly at 3.41 (Heat Flow Down) and 2.95 (Heat Flow Up).

Q: I have a Monier tile roof that has developed a leak. How can I find out if it was properly installed? The valleys are butted against each other. One tile broke and slipped down a few inches; I caulked it and pushed the tile back together. Should it be replaced?

A: There are a number of reasons that your roof may be leaking and having a broken tile is certainly a way for water to enter into the system. Caulking on a broken tile will usually work as a stopgap measure but this tile should be replaced as a permanent solution. Since you mentioned the closed valleys, am I to assume that the leak is occurring in that area? If this is the case, it may be necessary to clear away any debris that may have accumulated there. You did not mention which tile profile you have but if it is a flat tile, you may want to consider having the tiles cut away from the center of the valley to allow better drainage. Even though closed valleys are an accepted method of installing tiles in your area, they may become problematic if there is any debris accumulation that creates water diversion off of the valley metal. Sometimes it is sufficient to remove only those cut tiles that are creating dams or diversions in the valley. Another option, if you desire to keep the closed valleys is to use a ribbed style valley metal to replace what is probably a standard flat valley metal.

Q: As a rule, should fasteners penetrate the sheathing at exposed eaves on concrete tile applications?

A: There are no specific rules regarding exposed eaves. The Uniform Building Code UBC and ICC ES 1647 requires, only that the fastener penetrate the batten 3/4-inch or through the sheathing, whichever is less. Exposed fasteners at overhangs become an aesthetic issue that should be discussed with the contractor.

Q: I am looking to get a City of Los Angeles Research Report Number (RR#) for your roof tile.

A: Our LA RR # is 23700 and should be on file at all city building departments.

Q: I am using the Boral Roofing Villa 900 tiles. I would like information about proper installation around a skylight. I have heard about a product called Wakaflex . Can it be used for this detail?

A: The type of installation depends on the type of skylight you're using but for the sake of this conversation, I will assume you are using a standard curb-mounted skylight. Firstly, the curb-mount should be a minimum 2"x 6" but could be higher if you are using a counter batten system or step-flashing. Next, the underlayment should turn up at the curb on all four sides with the corners sealed to water proof the cut underlayment. If standard tile pan flashing is to be used, it should be installed at this point. The flashing around the skylight should form a clear path for water to be directed around and away from the skylight and back onto the tile at the downslope edge. If step flashing is used, each course can be fitted with MLT Wakaflex. This is a flexible, paintable less expensive alternative to lead and more eco-friendly. Wakaflex can be dressed under the skylight and used as a counter flashing down onto the tile to form a watertight fit.

Q: I am a contractor building my own home. The roof, floors and walls are going to be poured in place concrete. I would like to know the attachment for your roof tile given this type of construction.

A: Although fairly uncommon in this country, there are a number of methods for attaching concrete tiles to concrete decks. In Central and South America it is common to set the tiles directly onto the deck in a bed of mortar. Recently, two part polyurethane foam systems have been developed in place of the mortar for attachment. In this country, it is more common to mechanically attach the tiles over a layer of underlayment, most commonly an asphalt based product. The attachment of the tile is typically onto a raised batten system.

Q: Can the Barcelona 900 tiles be installed using a wire tie system in lieu of battens?

A: Our tiles may be installed using a wire tie system only if the system has specific code approval for use with our tile and provides evidence that it will perform equal to mechanically attached systems. Our company has performed both seismic and high wind testing for mechanical systems but not for wire tie systems.

Q: How much bleach should be used per gallon of water to kill moss, mildew and algae on the roof? Is full strength bleach harmful to the roof tiles? How does one determine whether sealing of the tile is needed? What brands of 100% clear acrylic sealers are recommended?

A: Full strength bleach may harm the underlayment (felt under tile). A diluted solution with agitation (water pressure) is preferable. A 10% to 15% solution of bleach to water, in addition to moderate water pressure (1200 psi) will, in most cases, clean the tile surface in the short term. The dynamics of organic growth on the tile surface will return, however, assuming conditions remain favorable. The primary purpose of the sealer is to prevent efflorescence showing on the tile surface during the curing phase of the concrete. Any additional sealer coats applied as a maintenance procedure would offer a temporary brightening of the color.

Q: I have a 17 year old house with asphalt shingles. Can I leave the shingles in place and install your tiles over this surface. Some of the shingles are curled. Would this affect drainage? Do I have to do a structural analysis of the rafter support system?

A: In certain jurisdictions, it is possible to install our tiles over existing asphalt shingles if the structure is shown to be capable of supporting the total combined weight of both roof systems. Depending on the design, you may be able to reroof without reinforcement but you should have this verified by an engineer or truss manufacturer before beginning. Whether the existing shingle will serve as a proper underlayment depends on the condition. If the shingles are curled, there is a good chance that the shingles are brittle and will likely experience quite a bit of damage during the process of re-roofing. It is generally advisable to install a new underlayment prior to the installation of the tile. Since you live in a hot climate, you may also want to consider optimizing your results by installing the tile on a counter batten or the Boral Roofing's elevated batten system this will increase the airflow beneath the tile which will help keep your attic much cooler. Other enhancements such as ventilation and radiant barriers may be considered if you want to have a measurable impact on controlling the heat gain into your home.

Q: We are a Florida-based company building a custom home outside of Chattanooga, TN. We are using MonierLifetile and had specified in our specs that the roof was to be pointed up with color-matched oxide. The roofer in TN is not doing this, for a variety of reasons, but the only one that we can't dismiss without researching is his claim that in that climate, pointing up will trap moisture due to freezing and thawing. Is this correct?

A: The practice of bedding and pointing the hip and ridge trim is common only in the hurricane regions of the USA. This method is helpful in reducing the risk of wind damage and preventing water infiltration. Bedding and pointing may require maintenance and repair in areas subject to repeated exposure to freeze-thaw cycles. There are other methods of weatherblocking such as Boral Zephyr Roll or Boral Figaroll Plus, that can be used in these areas that perform quite well if they are properly installed.

Q: Do you make a curved turret piece for Barcelona 900?

A: We do not produce a curved tile for turret sections although our Barcelona 900 tile lends itself fairly well to that application since it may be progressively overlapped to minimize the amount of cutwork that this application requires.

Q: I need a tile cutter to cut the concrete flat tiles with a punch hole.

A: While there are tile cutters that are used in some countries, they are not commonly used, nor are they commercially available, in the US market. Attempts to market cutters in the USA have not been successful due to the fact that most roofers prefer to use circular saws fitted with diamond blades. I would suggest that you may find it easier to purchase a dry-cut diamond blade that may be used on any circular saw and then use a masonry bit to drill holes where necessary for attachment.

Q: I'm considering your shake-look products and I've heard some conflicting information regarding the need to install "edge wrap" pieces. Is it required that these pieces be installed in order to have a valid warranty, or can your shake-like product be installed like real shake (which of course is not available in 90 degree bent pieces for end wraps)?

A: It is not an uncommon practice to install the flat tiles without the standard rake (90 degree) trim pieces at the side edges of the roof. Other options that may be used at the rake edge is to install metal rake trim or metal rake flashing or to fill the void beneath the tiles with mortar or other durable material to prevent birds or other vermin from entering.

Q: Do you have an approved installation for Spanish S tiles on a 5/12 slope at 40' +/- above grade in a 130 MPH wind zone?

A: The required uplift at a 40 ft. mean roof height, 130 mph wind zone, coastal exposure, is 35.1 ft-lbs. Two (2) screws, direct deck installation, provides 51.3 ft-pounds resistance which complies with the code. Polyurethane adhesive (66.5 ft-lbs) also complies with code guidelines.

Q: We have a MonierLifetile roof on our home in Santa Barbara, CA that was built in 1992. The tile is developing a discoloration that appears to be mildew growth. What is your instruction for removal?

A: There are a number of variables that affect the procedure so it is very difficult to come up with a "one size fits all" solution. However, the most common method for cleaning moss and algae from the roof is to soak the roof in a diluted solution of bleach and then power wash to remove the debris. Typically, a 10 to 15% solution of bleach (5% if pool chlorine is used) is sprayed onto the roof in an amount that soaks in rather than runs off the roof. After it dries, the roof may then be power washed to remove the debris. To slow the recurrence of the problem, the roof may be sealed with a high grade acrylic tile sealant that optimally has 33% solids with a wetting agent (ATS-13 by Infiniti Paints is a common brand used in Florida). This sealant should be applied to a thickness of 1 mil for normal wear.

Q: Do you have a UL design number for Boral Roof Tile for a two hour roof/ceiling assembly? The roof frame is steel (W12X22) with sprayed on fireproofing.

A: Boral Roofing does not have a UL design number for one or two hour fire ratings. All of our tiles are rated as Class A assemblies based on tests conducted in accordance with UBC Standard 15-2 which is essentially identical to UL 790, ASTM E-108 and NFPA No. 256. These tests are conducted under worst-case scenarios utilizing tiles installed onto wood decks of plywood or OSB so it would be logical to assume that they would meet the requirements of your project.

Q: The tile on our roof rattles and makes noise when windy; is there any remedy for this?

A: If you have tiles that chatter in high winds, you may want to consider applying a small dab of adhesive between the tiles at the overlap. It is unlikely that all of the tiles on the roof are uniformly affected so you may want to try to identify which tiles are chattering and then treat them accordingly. You did not include information regarding the slope and design of your roof or which style of tile you have but those issues may have an impact on your solution as well.

Q: I have your roof tile on my home and am in the process of installing a propane unit heater in my shop. What is the best way to run my 5" b vent pipe through the tile?

A: Any vent pipes through the roof regardless of size requires that two flashings to be installed, one worked in shingle fashion with the underlayment and the other with the tile. The flashings should be properly lapped and sealed to prevent water intrusion and the tiles may be temporarily removed and cut accordingly to allow for the pipe to pass through the tiles. You may want to reference page 17 of the 2006 edition Concrete and Clay Roof Tile Installation manual for Moderate Climate Regions.

Q: How does Boral Roofing Tiles compare to slate roofing?

A: Slate and concrete tile are similar in that they are both long-lasting, fireproof, rot and hail resisting roofing products that add significant value to the structures that are applied to. Both products are heavy, with concrete tiles ranging from 6-11 pounds per square foot and slates ranging from 10 to 16 pounds per square foot depending on type and application. Slate roofs are a double lapped product which means that the exposed length is less than half the actual length of the slate due to the full over lap of each piece. Concrete tiles have a vertical interlock that allows them to be installed with only a min. three inch overlap. There are quite a few other differences in how the products are installed and flashed but probably the biggest difference is in the price of the products. Most slate will cost approximately 3-10 times as much as concrete tile. Concrete tiles can be made with textures and colors that simulate slate so it is not surprising that most folks looking for that appearance will select concrete tile.

Q: Several years ago, the contractor who built my custom home installed Mission-S tiles without closing a gap at the eave with a birdstop. I would like to plug these gaps to improve fire safety. Is there a way to do this myself without removing the roof tiles?

A: Any material that will keep the birds from nesting beneath the tile will help to protect from fire damage. Since I assume you are in a high risk area, I would suggest that you use a non combustible material such as metal or mortar rather than wood or foam. Mortar works quite well but it is difficult to do a good job after the tiles are installed. Metal birdstops may be the best solution since they may be glued in place if conditions are right. How practical this is will depend on how the first course of tile is currently being supported. Is the tile resting directly on the roof deck or was a board or raised fascia installed to hold up the nose of the first course? If this was done, standard birdstop may not fit properly. There may be any number of methods that will effectively close this opening, but which one meets your aesthetic demands will depend on you.

Q: Do you have an installation spec for 130 MPH wind loading at 40' height above grade? The spec must comply with the requirements of Florida Building Code.

A: Fastening requirements are based on: Roof Slope Tile Profile Type of Installation (Batten or Direct Deck) Coastal or Inland Exposure As a general rule, however, the following methods would comply with the code: One Screw Two Ring Shank Nails Polyurethane Adhesive. You may want to reference 76-83 of the 2006 edition Concrete and Clay Roof Tile Installation manual for Moderate Climate Regions if you are outside of Florida. If you reside in Florida, please reference the 5th edition of the FRSA.

Q: We are a construction investigation firm. We just looked at a home built in 1981 with what appears to be the "Villa" style Monier tile installed. The material is installed directly over spaced sheathing without underlayment. Our installation manuals only go back to 1989. Would the installation instructions from 1981 permit direct application to space sheathing without underlayment as an alternative method?

A: In 1981, Monier tiles were allowed to be installed over open spaced sheathing per the provisions of ICBO ER 2093.

Q: What is the current spec for installing tile over a low slope concrete deck?

A: While there are no industry specifications for tile on a concrete deck, the following assembly has been used based on local code acceptance: Prime the deck (various concrete primers are available). Hot mop a Type 30 anchor sheet. Hot mop a Type 90 cap sheet. Mortar or adhesive set the tile based on the product instructions. The minimum slope for such an installation is 2:12.

Q: Can Boral Roof Tile be installed over a rigid perlite insulation composite board (with waferboard up) used as a substrate and surface for the battens to be fastened onto? This composite insulation board sits on a metal deck.

A: Boral Roofing tiles may be fastened to the perlite/waferboard as long as the manufacturer of the board has evidence to support this type of application. Since the Boral Roofing installation instructions are based on convention construction designs, it is only necessary to show that your proposed construction provides support and fastening equal to that of wood sheathing attached to conventional wood framing. If the substrate you've selected does not provide adequate attachment, you may want to consider attaching your vertical battens through the perlite board with screws and into the metal decking. The horizontal battens to which the tiles are attached may then be fastened with screws to the vertical battens.

Q: I have an open beam ceiling with 2x6 tongue and groove. I have a 1 inch sheet of insulation with shakes over that. I want to add 2 more inches of insulation over the existing. What has to be done to install the Cedarlite product?

A: Since you have an existing shake roof, I would assume that the shakes are attached to 1"x 6" spaced sheathing that is installed above the 1" insulation. You did not mention whether you intended to remove the 1"x 6" or add the new insulation on top of it. Whichever assembly you select, you should be cognizant of the need to attach the new roof deck and/or roofing material to the support system of the roof. In your case this would be either the 2"x 6" roof sheathing or the rafter system. The Cedarlite tiles may be attached directly to a solid roof deck or to a minimum 1"x 3" batten. As long as you make certain that the roof deck and/or batten is securely attached to the roof structure, you may proceed as normal with your installation. I would also like to point out the importance of proper ventilation on this type of application. The UBC building code requires ventilation of roof structures and this includes open beam and cathedral ceilings. There should be some space in your assembly for venting.

Q: Can hip and ridge sealer be used as a glue to hold small cut tiles in place? I want to hold tiles at the valleys of my new roof because I hear that you aren't supposed to nail at the valleys.

A: Unless the manufacturer specifically states that his material is designed for the attachment of concrete roof tiles, I would not use it as such. There are other adhesives available that are specifically designed for the attachment of cut tile pieces and they may be used to attach individual tiles to adjacent tiles that are mechanically attached. When using these adhesives on steep slopes or in valleys, it may be necessary to further attach the tile with wires to keep them from sliding prior to the adhesive bond as long as the sealant is one part polyurethane.

Q: Does Cedarlite meet the new building code requirements for a 120mph zone. Do you have test data supporting claim?

A: The Boral Roofing SBCCI compliance report (Standard Building Code evaluation service) #9460B includes Cedarlite: 120 mph 3-second gusts equate to 90 mph sustained wind speed listed in that report. Polyurethane adhesive or one screw will comply with these wind uplift requirements.

Q: One local contractor has told us that it is not necessary, in his opinion, to nail down EVERY tile. His usual practice is to only nail the tiles around the perimeter. How important is it that every tile is nailed down?

A: There are a number of different fastening requirements for concrete tile depending on the type of application, the roof slope and the local building requirements. The Uniform Building Code Table 15-D-2 stipulates that tiles installed on battens need only to be fastened at the perimeter of the roof (three tiles in from eaves, rakes, ridges and hips)at slopes less than 5:12. From slopes of 5:12 to 12:12, alternate courses must be fastened in addition to the perimeter. Above 12:12 all tiles must be fastened. In areas designated as snow areas by the local building official, all tiles must be attached with two fasteners or with one fastener if installed on battens. Your contractor may very well have had good success without fastening all tiles, but these are the code requirements and are the same as the MonierLifetile recommendations.

Q: Is the warranty valid if my roof is not installed according to your installation instructions?

A: Unfortunately, Boral Roofing has very little control over how our products are installed. Fortunately, we do not necessarily void your warranty due to improper installation. The Boral Roofing warranty is specifically for the physical properties of the actual tiles and not the roof installation. Hopefully, the installation inconsistencies on your roof are minor and will not affect the performance of the assembly. Unless the method of installation has caused harm to the actual tiles, your product warranty should be intact.

Q: I am planning to build a home on the salt water marshes of Cape Coral, FL in the 130 MPH wind zone. I plan to use a lightweight slurry coat concrete tile but I do not like the idea of a urethane foam mastic tie down. I want to use stainless steel mechanical tiedowns. Do you have product approval for this system?

A: The preferred method of attachment is a full or medium foam paddy for two reasons: 1) The method provides the highest resistance values. 2) It provides added support for the lightweight tiles. Our Product Approvals ( FL 601-R3 and FL 7849) also reference the use of approved mechanical fasteners.

Q: What is the roof material wind resistance rating for concrete "S" tile?

A: Uplift resistance values are based on wind zone, mean roof height, roof slope, the particular fastening system proposed, as well as tile profile. Wind speeds to 150 mph are referenced page 76-83 of the 2006 edition Concrete and Clay Roof Tile Installation manual for Moderate Climate Regions if you are outside of Florida. If you reside in Florida, please reference the 5th edition of the FRSA.

Q: When installing barrel tile, is it necessary to use drip edge along with the metal that covers up the rises in the barrel tile?

A: Drip edge is required by code for all concrete and clay tile roofs, in addition specific to your concern regarding a profile specific metal designed to close-off the openings on a high S profile tile is required by code as well.

Q: I am in the process of finishing working drawings for renovations to my existing ranch style home. My intent is to transform the house into a Norman Cottage. French farm houses typically had tile roofs and I would like to be true to this architectural style. However cost and weight are concerns. The roof is the dominant feature and highly visible on my home. I have a steeply sloped wooded site with the house sited well below the road. I am planning to increase the roof pitch to 9:12. What options would you suggest, and what can I expect to pay in terms of materials and installation. I have a design/build background, and currently work as a consultant to developers, builders, and designers, so this is a doubly important project to me.

A: Firstly, the weight of our tiles vary from approximately 6 pounds per square foot to around 11 pounds per square foot. Which tile would best suit your purpose would depend on the strength of the existing structure although, if you are planning to build up the roof slope, the rafter assembly could certainly be addressed during that process. The total installed cost depends greatly on the experience level of your roofing contractor. A tile roof in the Southwest US will typically cost less because it is close to the source of manufacture and tile happens to be the most common type of roofing material in that area. In areas where tile is less common, you will likely expect to pay two to three times more. There are also a lot of variables, such as roof complexity and accessibility that could impact the cost of the roof.

Q: My husband and I are in the process of selecting roof material to replace the Cal Shake that we now have. Our roof gets some foot traffic from window washers, painters, and other maintenance people. I am concerned about the effect of that traffic on Cedarlite.

A: While we generally do not encourage foot traffic on lightweight tiles, the Cedarlite seems to withstand traffic best when installed with a single screw in the center hole rather than the two nail method that is commonly used. If regular traffic cannot be avoided you may also consider using walk boards that can be purchased or fabricated. Another option is to apply an expanding polyurethane foam beneath the tiles as they are being installed; this is usually only applied to those roof sections likely to see foot traffic.

Q: I have a Monier Concrete Roof Tile on my home. It was built in 1980. The color is slowly eroding and the glaze is gone. How should this be maintained?

A: The color of your tile is not a true glaze but a surface coating referred to as a slurry coat. Unfortunately, this type of coating is susceptible to the oxidation and erosion that you are experiencing. Fortunately, there are some very good processes available for rejuvenating the appearance of the tiles and even the opportunity for changing the color if you so desire. There are a number of companies that specialize in this type of work depending on where you are located. There are a number of treatments that are used to rejuvenate old concrete tile roofs and most of the good ones involve a multi-step process of cleaning, priming and coating. The high-grade acrylics that are applied as the color coat will typically carry an 8-10 year warranty and can be expected to last much longer. In Florida they sometimes use a 100% acrylic tile sealant, ATS-13, made by Infiniti Paints. For product description and application data, contact them directly at 954-972-2225.

These applications do not affect the performance of concrete roof tile, however a rubber or synthetic based paints should not be applied to the surface of concrete roof tiles that are designed with a under and over-lock feature. The under and over-lock features are designed to engage one another vertically and act as functioning water channel.

Our warranty covers all of the physical properties requirements but specifically excludes color. Fortunately, the strength and performance of the tiles are unaffected by color loss.

Q: I need the specs/weight for an existing tile we have. It says Lifetile and Burlingame Industries. It's flat with squared indentations.

A: The tile you are describing sounds like the Chateau product that was manufactured by Lifetile prior to the merger of Monier and Lifetile. This tile weighed approximately 950 pounds per square or 9.5 pounds per square foot installed weight. The Chateau product has since been discontinued and is no longer produced at any of our facilities.

Q: The contractor wants to nail only the first row of the tiles. Please let me know if this is correct?

A: If the tiles are installed on battens and the roof slope is less than 5:12, the only tiles that need to be nailed are at the roof perimeters. The perimeters are defined as the first three tiles 36 inches from the eaves, rakes, hips and ridges. If the roof slope is between 5:12 and 12:12, alternate courses of tile must be fastened in addition to the perimeter tiles. Above 12:12 slope, all tiles must be fastened. In areas designated by the building official as high wind regions, all tiles must be fastened at all slopes. Lightweight tiles (< 8 psf) must be nailed individually at all slopes, in all regions. If battens are not employed, all tiles must be fastened at all slopes. In areas subject to high winds >90/mph, it is generally advisable to use an approved fastener for each tile.

Q: Is it acceptable to use roofing cement instead of mortar at head laps - where tiles meet wall or skylight?

A: The use of roofing cement is fairly common with clay and concrete roofing tile and is typically applied as an adhesive or weather blocking at small openings. Neither roofing cement nor mortar are acceptable as stand-alone replacements for code required metal flashings at any vertical roof intersection.

Q: With Cedarlite tile, how many nails are required to secure each tile that is placed over battens on the roof?

A: Cedarlite tiles are required to have one fastener per tile in all situations.

Q: I have Barcelona 900 tile on 6:12 roof pitch and need to add half-round dormer vents. I would appreciate any recommendations or details for flashing pop-up vents with the Mission 'S' tile.

A: If dormer vents are to be installed, you must first provide a flashing or diverter around the opening in the roof sheathing, making sure that it is installed in such a manner that no upslope moisture is allowed to flow into the opening. As the dormer unit is installed, it is important that water flow be directed around the dormer and onto the course of tile directly below the dormer; no water should be allowed to enter beneath the tile covering. If flashing the dormer over the tile, ideally the dormer will have a flexible apron at the front and sides to provide a matching contour fit to the surrounding tiles. The tiles on either side of the dormer should be cut close to the dormer but not so close as to create blockage or diversion of water.

Q: I am currently installing a new roof with your tile. It is a dual pitch 8 on 12 and 16 on 12. How many nails are required per tile? Are more required on the 16 on 12?

A: Unless you are in a designated high wind region, the tiles installed above 12:12 would all have to be fastened and those below 12:12 would require alternate tiles or all tile on alternate courses to be fastened. This would be in addition to all tiles within three feet of the roof perimeters areas; eave, ridge, rake/gable.

Q: We installed your tile on our roof. Looks great but unfortunately, with the spring melt, ice slid off the roof and broke many of the lower tiles. Can you send us information as to how far the last row of tiles is supposed to extend from the edge of the roof, unsupported by plywood?

A: A normal overhang on the first course of tile is usually less than two inches, the most common overhang is ¾ inch. Sliding snow and ice however must be prevented by the use of some sort of snow retention devices. Tile roofs can perform very well in cold climates but they must be installed in a very precise manner as it relates to ventilation and snow retention. To minimize snow slippage, snow retention devices should be installed on your upper or lower roofs. Please visit for further options on placement of snow brackets.

Q: I am interested in determining the flexural strength of your cement roof tiles. Do you follow a specific ASTM standard when testing your tiles? Do you have a minimum flexural strength your tiles must achieve?

A: Our concrete tiles must meet the physical property requirements listed in ASTM C1492, SBC Section 1509.7.1.3, UBC Standard 15-2 and ICBO Acceptance Criteria AC07. The transverse break strength threshold is roughly 300 psf for all of these standards.

Q: Can I walk on my roof? I noticed in the warranty you said you do not guarantee "damage to the tile caused by roof traffic or foreign objects falling on the roof".

A: Most tile roofs will support some foot traffic, as long as it is done properly, although special precaution should be exercised when traversing lightweight tiles. For standard weight tiles, it is generally enough to step on the lower edge of the tile where it is supported by the tile beneath it. Try to distribute your weight evenly and avoid impact as much as possible.

Q: My question deals with the use of polyiso insulations on top of dimensional wood decks using standard weight tiles on a 12:12 slope.

A: Polyiso insulation is commonly installed beneath tile roofs but is not recommended as the substrate for tile attachment. You would typically have the option of attaching ½ inch plywood over the polyiso and then proceed with a normal tile over a batten installation, or you may want to consider a counter batten installation where vertical strips are fastened to the wood deck and then the anchor battens are attached to those.

Q: I need technical advice for installing tiles in higher wind speeds.

A: There are a number of different methods for attaching tiles in high wind zones and the selection of the best method for you would depend on the specific circumstances of your job. Some of the variables to consider would be what wind speed are you required to resist, what is the roof slope, what style of tile are you using and how are the tiles to be installed (battens or direct to deck)? A simpler approach would be to follow the guidelines of the local Building Code: Each tile must be fastened. Wind clips must be installed on eave courses. The nose of all trim tiles must be set in a bead of approved sealant. This applies to most jurisdictions.

Q: We installed Duralite in 1995 and now we have to either replace or glue together some broken edge tiles. I read that there is a special adhesive for this?

A: The two most commonly used adhesives for fastening or repairing broken tiles are RT600 by Ohio Sealants or Rainbuster 850 by Topp Industrial. Both of these products should be readily available at most roofing supply companies.

Q: I have a MonierLifetile roof on a house that is 20 years old. Over the front entry we have a shed type roof supported by a cantilevered beam that in turn is supported by a diagonal beam. This area of the roof is sagging and needs repair. One contractor wants to jack up the overhang with all the tile in place and then put in a strong vertical support. I am concerned about the tile cracking. Is this the way to raise the porch overhang or should the tiles be removed?

A: Although it may be somewhat easier to lift the roof without the tiles on it, there is no reason that they cannot be left in place. Assuming each tile is fastened individually, they can sustain quite a bit of movement without damage.

Q: I have a question regarding the installation of concrete tile on the roof of my home. The home is 10-years-old and the tiles on the hips and ridges are slipping and falling. They were not nailed in at all. As the tiles have slipped, we have had water damage on the walls. I have had 3 roofing professionals evaluate the situation and they all say the tiles were not installed properly. They asked me to contact you and get installation specs. The tile is "s" shaped and stamped "Lifetile" on the back.

A: The Uniform Building Code specifically requires that all tiles be attached to the roof and that requirement has not changed since the time your tiles were installed. Tiles at hips, ridges and other perimeter are as are required to be mechanically attached in addition to the battens onto which the tiles are hung. Certainly, if tiles are slipping out then they were not adequately fastened and should be repaired. The fastening requirements are contained in the UBC Table 15-D-2 which is the same as the UBC Table 32-D-2 that was in force at the time of your roof installation. Please visit page 9-10 of the 2006 edition Concrete and Clay tile Installation manual for Moderate Climate Regions.

Q: I'm replacing my roof from wood to concrete tile and I would like to know if the temperature of my home will increase during the summer and if it will drop during the winter more with your roof?

A: Wood shake roofs are fairly efficient as an insulative layer but they are not usually as effective as a properly installed tile roof. Concrete tile roofs can be the coolest roof available when installed with that thought in mind. The way the tiles are installed creates an air space between the tile and the roof deck that serves as an effective thermal barrier against heat gain; this is due to the thermal mass of the concrete roof tile. The air space may be increased by using Boral Roofing's Elevated Batten System EBS, elevated vented eave closure and ridge venting system incorporated into the tile application. This will further benefit your heating and cooling cost by allowing convection which is the movement of air. Also, selecting a light colored tile will help keep the roof cooler during the hot summer months. During the winter, you will typically not notice a significant difference in temperature from when you had the wood roof on.

Q: One contractor has proposed to use clips to hold down each tile. My question is that he proposed to use stainless steel on the first course and then galvanized on the remaining courses. Is this standard practice or should stainless be used throughout?

A: The need for stainless steel is dependent on the immediate exposure to a corrosive environment. In any situation, the eave course will typically receive greater exposure than the rest of the field but this is not always so. Coastal areas (1500 feet from the shore) have the greatest exposure so I would recommend stainless steel on any roof within that area. Since your roofer undoubtedly has some practical experience in your climate, I would certainly factor in his opinion based on past performance but I would expect some pretty strong evidence to support the use of a less corrosive-resistant material.

Q: I have an AC unit on the roof. Do you have any suggestions to reduce the chance of breakage when work is done on the unit in the future?

A: While padded walk boards are commonly used by trades who have to work on top of tile roofs, there is a new approach that is being used that may work better for you. As the tiles are being installed, it is possible to apply polyurethane foam beneath the tiles that will expand to fill the void beneath the tiles and provide support that will reduce the risk of breakage under foot traffic. This can be done in isolated areas that are likely to be subject to frequent foot traffic.

Q: What is the best method of installation of Vanguard Roll tile in Florida on a 8:12 pitch roof?

A: System One using horizontal battens using 10d ring shank nails, # 8 screw(s), or polyurethane adhesive (foam) are all tested systems. Boral Roofing offers no preference. 5/8 inch plywood is required in some Florida jurisdictions. 15/32 inch plywood is the minimum industry standard. Venting, both low (soffit) and high (exhaust), are recommended by both the industry and Code: 1 square foot venting for each 300 square feet of attic space.

Q: I bought a home with a Duralite shake roof. I was told not to walk on the roof, or the tiles would break easily. The valleys get a lot of leaves in them all year from the oak trees. I was also told to keep the valleys clear, or leaks might occur. What should I do? Can I walk on the roof?

A: The concern for maintenance of valleys in situations such as you described is best addressed at the time of installation but in light of the fact that your roof is intact, here are some options to consider. The first one is to use an extension device to rake the leaves from the valley from a ladder set up at the eave. This option is practical for short valleys but may be impractical for longer runs. Another option that is best considered during the original construction is to cut the tiles away from the center of the valley far enough to allow you to step on the valley metal rather than the tile as you clean the area. This method also greatly reduces the concern for roof leaks since the water runs more freely down the center of the valley. It is possible to have the valleys cut open later, but it is much easier during construction. Valley metals with additional longitudinal ribs on the sides will also help to prevent clogging and lateral water diversion. If neither of these methods are feasible, you might consider using padded walk boards that are commonly used by painters or other trades who have to work on roofs of this type. There are commercially prepared versions of these or you may consider fabricating some from sections of plywood with padding attached. This method should only be used on reasonably shallow roof slopes and caution should be exercised to prevent slipping. It may also be possible to find contractors in your area who actually specialize in providing this type of service. The other option is to apply EPS or polyurethane foam beneath the tiles in the areas that you need to access. The polyurethane foam in particular may be viable in your case since it often may be applied without removing the tile.

Q: How quickly will all the scratch on my new roof go away? Also, what is the recommended distance or overlap on gutters? In some areas, I only have 1" of clearance.

A certain amount of surface scuffing is unavoidable during the installation of a tile roof. How long it takes the scuffs to blend into the surface depends on a number of variables including tile type, climate conditions and roof slope. While we do not specifically monitor the length of time, since it diminishes gradually, we do not see or hear reports of these scuff marks remaining for long periods. A simple solution is to apply a single light coat of acrylic clear spray paint to the areas with scuff marks There are no specific guidelines established for gutter placement other than to ensure that water flow is captured by the gutter. This is an issue that must be coordinated between the roofer and gutter installer, however, the standard size gutter for a home residence is 4-6 inches and typically the first course of roof tiles have an overhang of ¾ inch min to 1 inch.

Q: What is the recommended type of nails we should use to install rake tiles? The concern here is that these nails are exposed to the weather given they are visible along the sides of the homes.

A: The UBC building code requires only that the fasteners be corrosion resistant and penetrate the framing a minimum of 3/4-inch. The degree of corrosion resistance required will typically depend on the climate and environment. The minimum corrosion resistance noted in the latest TRI Installation Guides calls for nails complying with ASTM A641 Class 1. In coastal areas or other areas known to be highly corrosive, stainless steel or other non-ferrous materials may be considered. In high wind regions an, additional bead of sealant at the head-lap of all rake/gable trim tiles regardless of the profile of tile.

Q: I would like to collect rain water for general use of our roof. Are your roof tiles suitable for this kind of application? Is there any toxic materials mixed into the concrete of the tile or used for the glazing?

A: You should contact your local municipality regarding their filtration and storage standards for drinking water. However, because our tiles are made from sand, cement and oxide coloring, there are no chemicals added and nothing that would prevent you from using them for catchments with proper filters.

Q: What is your position on the use of radiant barrier under concrete tile roofs with 90# membrane that is hot mopped lapping joints. Will this adversely affect the life of the membrane?

A: Radiant barriers come in several forms, i.e. rolled material, paints, laminates, etc. They are generally effective at reducing attic temperatures in the summer. Generally, if the roof installation, methods, and workmanship keep the system as dry as possible--and if the system allows air flow--this dynamic will extend the life of all the components.

Q: What kind of roofing material do you suggest as underlayment for your tiles installed in Florida?

A: The minimum underlayment in Florida is a Type 43 coated base sheet. This would be the minimum used with the current System One as per the FRSA/TRI Installation Manual. Upgrades such as heavier felts or modified bitumen membranes are also used based on type of installation system and budget. Heavier or more stable underlayments such as Boral Tile Seal, provide additional assurance against roof leaks and premature system failure.

Q: We are designing with your S tile, and I need to know the maximum roof slope for this type of concrete tile. The design wind load for the area is 130 mph.

A: There is no maximum roof slope for the installation of our tile although, above 24:12, the tile is considered as wall cladding and must be fitted with a nose clip to prevent chatter. In wind areas of 130 mph, calculations must be performed based on the roof slope, mean roof height and method of application.

Q: Is there an insulation difference if using a flatter, slate-type tile as opposed to one with a rounder shape. It seems there would be less air circulation under the slate type.

A: You are correct in your thinking that a profiled tile will allow more circulation between the roof deck and the tile underside which, in turn, will reduce the heat gain into the attic. The effect may be further enhanced by installing the tiles on a counter batten or utilizing Boral Roofing's Elevated batten System (EBS), elevated vented eave closure and ridge venting system incorporated into the tile application. The way the tiles are installed creates an air space between the tile and the roof deck that serves as an effective thermal barrier against heat gain. The elevated batten system has the added advantage of reducing the chance of roof leaks and extending the life of the underlayment and batten system.

Q: Does the concrete tile crack after long exposure to the sun? Any special advantages of using concrete tile versus clay tile? Does it discolor after long period of time?

A: Concrete tile does not crack from long term exposure to the sun. Some of the advantages of concrete tile over clay tile are the greater color and profile selection, lower installed cost and better walkability. Roof tiles are subject to a certain amount of oxidation and surface erosion that will result in some appearance change over time but the degree of change will depend on which type of tile is selected and the climate conditions where it is installed.

Q: I have a contractor who is insistent that he can provide a hot mopped underlayment for a tile roof. I know there are asphaltic products that can withstand a steep slope but they are specific and they are associated with built up roof systems.

A: The so-called 30/90 hot mop system is probably limited to a 7:12 roof slope, although some roofers will install it on steeper slopes. This underlayment system has a long history under tile, especially in southeast Florida. This sealed system would be an upgrade in the Tampa area (it is the minimum requirement in Miami-Dade). In recent years, the advent of "peel and stick" underlayments such as Boral Tile Seal, has removed the risk factor of working at steeper slopes when using hot asphalt.

Q: What does the term "slurry" mean in a tile description?

A: Slurry is a cementitious coating applied on a grey tile body during the manufacturing process. Slurry colored tiles are brighter, and the color-through tiles have a more matte finish in comparison. Slurry tiles are sometimes referred to as color coated tiles.

Q: In order to enhance energy efficiency I am considering using TechShield Radiant Barrier OSB Sheathing on our house. Do you know if this type of sheathing will have any negative effects on the Cedarlite tile and if you have any recommendations regarding the use of this product with Cedarlite?

A: It is quite common to use OSB with radiant barriers as a substrate for concrete tile application. We are not aware of any problems associated with this application and, given the physical properties of the tile it is not likely that it would be affected by the reflected heat than can affect other materials, such as asphalt and chemical based materials.

Q: Since the tile is usually nailed to battens I assume the tile is designed to provide a watertight seal. The felt membrane provides a cushion and protects against condensation and occasional water intrusion. If this is true, then if you have a leak the cause is either broken tiles or improper vents/exhausts or perhaps porous mud around ridges. Is this correct?

A: All steep slope (>2.5:12) roofing materials, including concrete roof tiles, are considered as water-shedding assemblies and are not water-tight. The purpose of the underlayment, in most cases, is to serve as a back-up system in the event that water gets underneath the tile. The amount of water that gets under the tile is minimal in all but the most severe weather conditions. For example, the current System One Florida application relies on an unsealed underlayment for protection. This systems utilizes top flashing over the tile to provide positive water flow away from the underlayment. If a roof leak occurs, it is usually due to a breach somewhere in the underlayment or flashing system.

Q: I got an estimate by a local roofing company who installs your lightweight product and he doesn't install the batten boards under the tiles. Is that okay?

A: As long as the tile is being installed between a 3:12 and 7:12 roof slope, the roofer may attach the tiles directly to the roof deck.

Q: I would like to know the difference between clay and concrete tile.

A: Clay tile is cured in a kiln using very high heat (approximately 2000 degrees). Concrete tile is a mixture of sand, cement, coloring oxides, and water and is cured at much lower temperatures (approximately 130 degrees). Clay tiles and concrete roof tiles have decidedly different physical properties even though they are tested to the same ASTM standards in most cases. Clay tile is limited to the colors of the raw materials or can be glazed employing more color options. Cement tile is available in many colors, both color-through and slurry coated.

Q: I need to know the moisture (water) absorption rate for concrete roof tile versus clay tile.

A: Concrete roof tile will average between 8% and 10%. The code allows 12%. Clay tile will average slightly less than 8%.

Q: We got two quotes from roofers on reroofing our house with Boral Roofing tile. The roof pitch is 20 degrees. One installer says we need battens and the other one says we do not need them. Who is correct?

A: At a 20 degree roof slope (4:12) battens are optional. At this roof slope, the tiles may be fastened directly to the roof deck as long as each tile is, in fact, fastened to the deck. If battens are incorporated into the installation and the roof is not located in a designated high wind area, standard weight tiles may be hung on the battens without fastening except for the perimeter areas as defined by the building code. Lightweight tiles must be fastened in all situations regardless of wind zones or batten status.

Q: Which do you recommend for the mud, use as an oxide or paint after installation?

A: Oxide coloring in the mortar work has a more natural look. However, a concrete stain is common industry practice. The ageing process is probably similar for both applications.

Q: I am a structural engineer on Maui. We are considering specifying your roof tiles but I need to examine the impact of lightweight vs. normal weight tiles. Could you supply me with estimates of the light and normal weight systems (psf) that I can use to evaluate the impact to my roof framing?

A: Our lightweight tiles weigh approximately 6 pounds per square foot and our standard weight tiles weigh between 9-10 psf. You should be aware that our lightweight tiles are not recommended for roofs that require frequent foot traffic or extremely high winds. Since Hawaii wind speed design is for 105 mph, lightweight tiles would require wind clips to be installed on each tile.

Q: Will your roof build up ice on edge of roof using standard weight slate tile? What is the best application method?

A: The formation of ice dams or icicles on the down slope eave of any roof is usually the result of building heat loss that melts the snow on the roof which, in turn, runs down the roof surface until it encounters the colder, ambient air temperature at the eave where it freezes and accumulates. The best way to avoid this problem is to install the combination of good insulation and balanced roof ventilation. There are a number of ways to accomplish this but there are also many variations depending on the design of the building and roof structure. The best information regarding this fairly complex issue is the WSRCA/TRI DESIGN CRITERIA FOR CONCRETE AND CLAY TILE IN COLD AND SNOW REGIONS. If your roofer or designer does not have a copy of this book, you may order one from the Tile Roof Institute at Concrete tile roofs can be the best solution for severe winter climates but it is essential that attention be paid to proper installation for these regions. In essence, the roof should be well ventilated, the tiles should be installed on a counter batten system and snow retention devices should be considered to avoid the possible damage caused by cascading snow. There are many different ways to accomplish these tasks but the method you employ will depend greatly on the specific design of your project.

Q: Can roof tile be installed at a 4:12 pitch without battens? Is this preferable, and if so what is the recommended fastener?

A: Battens are optional from a 4:12 to and including 7:12 roof slope. There are several fastening options, i.e. screw(s), two-part adhesive, or one-part adhesive. These are the most popular options and are all wind rated fastening systems.

Q: I am about to sign contracts to install your tile on my new home in Florida. The home must meet 120 mph windloads. My local building official requires documentation that your tile, applied with the roofer's suggested "foam down" method, meets the FL code requirements. Can you provide me such documentation or tell me where to find it? Also, I believe I understood my roofer to say that no screws or nails are used with the foam down method. Is that correct?

A: Wind requirements are based on several factors; in this case wind zone (120 mph), mean roof height (unknown), roof slope (<7:12), exposure (unknown), and tile profile (medium). Based on worst case, the requirement at a 60 ft mean roof height is 31.1 ft-lbs. The resistance value of a medium paddy (two-part foam) is 45.5 ft-lbs. The one-paddy system would comply to 25 ft mean roof height based on 11.4 grams per paddy. Larger paddy size would increase resistance. Code bodies approve foam permit applications on a regular basis, and have resistance values based on the manufacturer's recommendation.

Q: I am in the process of building large spec homes in Montana and was wondering if there were benefits to using concrete tiles to enhance a cold roof design?

A: Properly installed tile roofs actually create a sort of cold roof by the way they are installed. The space created between the tile and the roof deck allows for ambient air to cool any heat loss that may escape the roof system. This is one of the reasons that tile roofs are the preferred roofing material in alpine regions around the world. The method of installation in severe winter climates however is very important and I would suggest that you reference the WSRCA/TRI Design Criteria Manual for Cold and Snow Regions for more specific information regarding your roof.

Q: What is the R-Value of your roof tiles?

A: The value assigned to concrete roofing tile by ASHRAE is .13 although the concrete tile roof assembly which includes roof sheathing, underlayment and 3/4-inch dead air space amounts to 3.41 (Heat flow down) and 2.95 (Heat flow up). The actual value may vary somewhat, depending on the method of installation, slope of the roof and the materials used. The above values were based on a 45 degree slope.

Q: Can we use your roof tile for water catchment? How safe is it to drink this catchment water, if filtered correctly of course. Is there any adverse chemical runoff associated with this roof? We have land that is going to be used for organic farming with the roof used for catchment.

A: Because our tiles are made from sand, cement and oxide coloring, there are no chemicals added and nothing that would prevent you from using them for catchments with proper filters.

Q: My current roof has a class 4 rating. What rating does the Saxony Slate carry? Do you have any data on how it performs in hail? i.e. how big of a hail stone does it take to damage the tile?

A: We have completed our impact testing against the FM 4473 standard and are awaiting the final report for publication. Our flat tiles, which include Saxony Slate achieved a Class 4 level and our other standard weight tiles all achieved a Class 3. To achieve a Class 4 rating, the tile must sustain 6 separate impacts on a single tile without breaking. The ice ball size for Class 4 is 2-inch diameter.

Q: I purchased and installed your tile roof, and it looks great. The installation guidelines do not specify an exact overhang at the eaves for the tile. Is there a minimum overhang (1/2 in?) code requirement? If so, what is it?

A: Most codes do not define a minimum overhang although 1/2-3/4 " has always been sort of an industry standard. The reason the code doesn't address this is that there are so many different circumstances that may affect what is required in any given area. In areas subject to heavy snow accumulation, for instance, overhangs are sometimes eliminated altogether and replaced with metal flashing. As long as the water is effectively directed off of the roof, the length of the overhang is left to the owner and contractor. It is perhaps more important to make certain that there is not more overhang than needed. In high wind zones, this can be the initial failure point of a roof system.

Q: What underlayment and installation methods are recommended for concrete tile roofs? I have roofing contractors debating over whether or not I should use Coolply or similar foiled sheathing under your Split Shake tile. One says tile manufacturers recommend against it because their tile bakes from underneath. What is the official Boral Roofing position?

A: Our parent company has done extensive testing on the use of radiant barriers and has many years experience with concrete tiles being used with radiant barrier underlayments and have no reports of any problems associated with this practice. Our research clearly shows that radiant barriers installed with a properly installed tile roof on a counter batten system results in the coolest roof assembly of any tested. Your roofer may be confusing the issues since asphalt shingle manufacturers tend to remain concerned about the effect it will have on their product since it is applied directly to the sheathing and is not as durable as concrete tile. Since you are obviously concerned with heat reduction, I would suggest that the most important component that you should insist upon would be the elevated batten or counter batten system.

Q: How long does it usually take for repair tile (new) to fade and blend with the existing (old) tile on the roof?

A: Since there are a number of variables that can affect the weathering of tile, it is difficult to say precisely when a replacement tile will match the shade of the existing roof. Likewise, different types of tile will have different rates of weathering depending on whether they are surface colored or integrally colored. The weathering process happens gradually but we would expect that once the surface sealer has worn off, the tiles would be reasonably close in appearance. The sealer loss also occurs gradually depending on exposure but most of the visual effect of the sealer will be gone after five to ten years. It should also be noted that darker colored tiles are most likely to exhibit contrast between the color shades of the new and old tiles. If the contrast of the replacement tile is considered a significant problem, it is quite common to harvest tiles from another, ideally isolated and hidden, part of the roof to be used for the repairs and the new tiles may be substituted onto the vacated area where they will gradually begin to match the original roof without causing a visual distraction.

Q: What level of energy cost "penalty" am I likely to incur by going with a Dark Charcoal Blend Slate roof versus a white color slate tile?

A: While color is an important factor in the thermal transfer of heat into the attic, it is not the only one. The thermal mass of a concrete roof tile slows heat transfer, the air space between the tile and the deck acts as an insulator, and the air permeable nature of individual tiles (air movement through the gaps between the tiles) all contribute to lowering attic temperature. Also, standard insulation of the attic space plus radiant barriers and attic ventilation contribute as well. The impact of color is not quantifiable specifically other than to say that white performs better than charcoal in heat transfer studies. To measure specifically, the other factors mentioned must be taken into account. The fact that current home construction involves generally up-to-date insulation does mitigate the effects of the color of the roof tile. The rule of thumb is to select the color most consistent with the architectural intent of the home.

Q: In the ICC installation guide, a 3" head lap is specified for concrete tiles. How much variation is allowable? Would a 2 1/2" head lap be acceptable?

A: It is required that the roofer prepare the layout of the roof for a minimum three-inch headlap of the field tiles, with the exception of the Cedarlite and Madera roof tiles. Minor variations due to variances in tile lengths or roof inconsistencies are fairly common and will typically not affect the function of the roof. If however, the entire roof has been installed with less than the required headlap, it could make the assembly more susceptible to wind-driven rain in severe storm situations. This is less of a hazard on steep slope roofs and may never actually result in roof problems at all. If you are having problems related to this issue, I would discuss it with your contractor to see what could be done to correct the problem.

Q: I have a Roma style tile roof on a residence that is not on solid sheeting - vintage 1984 - and need to know if this was ever approved to be installed without solid sheeting?

A: The Roma style was approved for application over open spaced sheathing in 1984 provided that the roof slope was above 3 3/4:12 and the roof was not installed in an area subject to ice and snow build-up or hurricanes.