Over the past decade, Oriented Strand Board (OSB) has become increasingly popular as an alternative to plywood, not only for new construction but also for reroofing projects. Designers and builders are using OSB more often primarily because it reduces the overall cost of a roof system.

Despite its popularity, until recently no one addressed the lack of UBC Code fire ratings for roofing systems using OSB. In California and other fire-prone regions of the United States, designers and consumers place great emphasis on fire ratings and the fire performance of roofing systems. Accordingly, the absence of any laboratory testing of OSB began to cause some concern.

For the last several years, testing laboratories and code officials have been trying to address the lack of direction on this issue, but not until earlier this year did the International Conference of Building Officials (ICBO) begin to deal with the problem directly. In a code hearing in January, the ICBO-ES board determined that the fire rating of any roofing material over OSB must be determined through proper testing of the entire roofing assembly. Basically, this means that roof systems previously tested over plywood now require testing over OSB. Although this requirement may seem redundant, significant evidence exists showing that the performances of different roofing systems may vary when OSB is used.

In accordance with these requirements, tile manufacturers decided - as an industry - to fire test our tile roof systems over OSB. Because tile is generally thought to be one of the best choices for fire-retardant roofing, the tile manufacturers felt an obligation as an industry to perform the required testing of our tile systems to assure our customers of their expected performance. In June of this year, tile manufacturers performed full-scale fire testing of concrete and clay tile - standard weight and lightweight - on OSB. Results were positive: when installed on OSB in accordance with the UBC, our concrete and clay tiles achieved the highest fire ratings (Class A) as products and systems. As an industry, we have recently published a test report that provides the supporting documentation.

All specifiers and users of roofing materials need to understand this new, additional testing requirement by ICBO-ES. Make sure that the roofing material you choose has been properly tested on OSB and that you know its corresponding fire rating. In the past, many people have been confused about the performance of "products" versus "systems" in regard to plywood. Although a product may have a Class A fire rating, as part of a roofing system, it may have additional requirements or limitations during installation that must be addressed to retain that Class A rating.

Now, with the addition of the new ratings for OSB installations, more potential for confusion exists. If you have any questions about the fire rating of your selected roofing material, contact the manufacturer or ICBO-ES for further clarification. At minimum, as consumers, you should ask your material supplier to provide a written statement regarding their new rating on OSB.

The tile industry supports ICBO in its decision to clarify this ongoing problem with OSB and is happy to report the successful testing of our products, which hold Class A fire ratings as individual products and as complete roofing systems. For more information about this topic, please visit our website at www.rooftile.org

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For decades, architects and roofers worldwide have installed multiple shades of tile in either random or set patterns to create distinctive roof designs. Known as "blended" tile, this special feature has increased in popularity in recent years, primarily due to the numerous design options that blended tile offers and the added value and beauty it brings to any structure.

Contractors typically use one of two methods to install blended tile. They either select two or more solid colors from pallets of tile of specific shades and blend them together on the roof, or they use "factory-blended" pallets of tile. With the latter method, colors are pre-blended at the factory and delivered to the job site with multiple colors on a single pallet.

Proper blending requires careful tile placement. The tile installer is responsible for insuring that the placement of the tile is completed in an aesthetically pleasing manner to the owner. Accordingly, during installation, roofers must routinely check the appearance of the roof from ground level. Such care insures that they achieve the desired design effect; however, this extra scrutiny may require additional personnel on the ground to evaluate the tile arrangement. Contractors should keep this in mind when estimating labor costs for the installation of blended tile.

Even with factory-blended pallets, roofers must constantly evaluate the distribution of tile on a roof. The resulting roof pattern depends not only on how tile is stacked on a roof but also on the order in which tiles are taken off the pallets and installed on the roof. Improper layout can cause "hot spots," which occur when several tiles of the same hue are installed close together on the roof deck. Left undetected, these hot spots can create patches of color that negate the blended effect and result in additional labor to correct the problem by moving the tile. For this reason, in all their installation guides, the tile industry has always recommended that roofers check to insure that hot spots are not being created during installation.

Architects and builders have used blended tile for many years to add diversity and aesthetic appeal to buildings of many types, and their recent, increased use of this technique will most likely create even further demand. But, as a roofer, you must make sure that the appearance of the tile, once installed, achieves the proper blending effect when viewed from the ground. Moreover, you must estimate your costs for installing blended tile based on the additional personnel required to accomplish this task.

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This week I received several telephone calls from people in the South Florida area asking about how to evaluate the quality of roof tile. In one case, the question pertained to a specific imported clay tile product being considered for a large restoration project. The individual was asking a simple question: How do I know this is a good product?

Florida has a large construction base that consistently provides a strong demand for tile, which means that many new and different types of tile products continue to become available in that market. Currently, no one source is able to monitor all of these products entering the market; however, as with any building product, numerous code requirements and regulated product approvals can help guide you to a greater confidence level when selecting the appropriate roof tile for your project.

Metro Dade County and Broward County both provide individual product approvals for building products that are to be used within their jurisdictions. Likewise, the Southern Building Code Congress International (SBCCI) provides product compliance reports for building materials used in the southeastern part of the United States. Depending on your precise location, you will be covered by one or more of these code jurisdictions. In some areas, you may be required - as part of your building permit process - to provide evidence that you are using products with one or more of these approvals.

The roof tile industry has been actively involved with all of these agencies to help determine the most suitable code language to use to address the physical properties that should be considered for tile. In particular, the industry has recommended focusing on product testing procedures, tile tolerances, quality controls, and methods of maintaining ongoing assurances of the high level of quality products. The roof tile industry has also helped in the development of two ASTM standards for tile. ASTM is a nationally recognized standard organization that has published ASTM C-1167 for clay tile and ASTM C-1492 for concrete tile.

As a user of tile, you need to make every attempt to ensure that the products you are about to use conform to one of the above-listed standards. Companies that are members of the Roof Tile Institute meet these standards. Although many fine tile products are currently available in the market place, a few imported tile products have reportedly failed to perform when installed. Because some manufacturing facilities are in remote countries, local code agencies do not have the same opportunity that they do with domestic manufacturers to provide onsite inspection and compliance testing of the manufacturing processes being used. In some cases, sample products supplied for testing may not be the same as the products that arrive at the docks or projects.

Additional factors other than demand can influence the availability of imported products. Economic conditions in countries abroad can glut domestic markets or severely restrict shipments. The volatile cost of ocean freight also creates some uncertainty in long-term pricing.

Roof tile continues to increase in popularity and usage across the country. With just a simple bit of research about the products you plan to use, you can help ensure the quality installation and performance of your selected roof tile product. So, how do you know you have selected a quality roof tile? The best answer I can provide is: ask the supplier of your tile to provide you with documentation that addresses quality, codes, and approvals of the tile you are about to use. The Roof Tile Institute can also provide accurate answers to any questions or concerns you may have about the proper selection and use of tile. Please visit us at www.Rootile.Org for more information.

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Tile Roof Maintenance

 

With proper planning and design, quality materials, and professional installation, tile roofs can last 50 to 100 years or more. That's because tile not only is resistant to pests but also withstands fire and harsh weather better than other roofing products. But, improper drainage, gutters filled with debris, and careless foot traffic can damage roofs of all types, tile included.

To protect your investment and prevent potential problems, inspect your roof regularly. And, because tile roofs possess some unique features, use professional roofers experienced with tile roofs to perform maintenance and cleaning, when necessary.

Walking on a Tile Roof
Walking on any roof is dangerous, but walking on a tile roof can damage tiles, if not done properly. Even though tile is one of the most durable roofing products available and hardens with age, walking carelessly on it can cause breakage.

Chimney sweeps, painters, and even roofers should avoid walking on tile roofs unless absolutely necessary and, when such times arise, they should do so with extra care. For heavy or continued foot traffic, workmen can use sheets of plywood covered underneath with carpet or foam to prevent slippage and distribute weight. For lighter traffic, they should avoid the more fragile tile edges and instead walk on the bottom three inches or "butt" of the tile that overlaps with adjacent tiles, moving gently and carefully parallel to the roof's ridge.

Dealing with Occasional Roof Repairs
Under normal circumstances, tile roofs are virtually maintenance free. However, the ultimate longevity of a tile roof depends on the quality of all elements of the roofing system. For example, many leaks are caused not by tile failure but by damaged or inferior underlayment or flashing. If this occurs, qualified tile roofers can remove the roof tiles, address the cause of the problem, and then replace the tiles intact.

Tiles do sometimes break - from falling tree limbs or inexperienced craftsmen on the roof. Homeowners should not neglect broken tiles, as they can compromise the roof's waterproof surface and damage the underlayment by allowing exposure to sun and rain. Fortunately, roofers familiar with tile can repair or replace roof tiles quickly and easily, and manufacturers can help match the color and style of the original tiles with their replacements.

Regional Concerns
Certain climates and regions have special issues to address, such as snow accumulation in the north and mold and mildew growth in humid areas of the south. Proper building and roof design and/or routine maintenance can minimize these potential problems in both regions. Many homeowners living in areas of heavy snowfall mistakenly believe that snow accumulation on a tile roof is dangerous; so, they arrange for snow removal, which - in most cases - is not only unnecessary, but also dangerous and potentially damaging to the roof tiles. What many people do not know is that snow is an excellent insulator and snow guards or snow fences placed strategically across a roof's surface can keep snow safely on most roofs until it melts gradually in the spring.

In contrast, residents of south Florida and regions like it often contend with mold and mildew. High humidity and warm temperatures encourage their growth on all exposed areas of buildings, not just roofs. Because mold and mildew usually thrive in areas of shade or moisture, the best remedy is prevention - through proper drainage and roof design that exposes shadowed and wet areas to sunlight. If mold or mildew does develop on a tile roof, however, professional cleaning once or twice a year should effectively remove them. The cleaning must be performed by professionals familiar with tile roofs, using a pressure cleaner or regular water pressure and environmentally friendly cleaners.

For More Information
No matter where you live or what type of roof you have, chances are your roof needs regular inspections, maintenance, and cleaning. For tile roofs, make sure these tasks are performed by professionals experienced with tile roofs because, with their assistance, you can ensure that the beauty of your tile roof and the protection it delivers truly last a lifetime.
 

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