Tyler Allwood, Director of Business Development, Eagle Roofing Products
Concrete roof tile is well known in many areas of Florida, so much so that Florida is occasionally referred to as a tile market. This is a misconception and, in fact, much of Florida is a roof tile desert. Some roofing contractors are aware of concrete roof tile, but have, for one reason or another, chosen to not offer it to their customers. There are others that have installed concrete roof tile but avoid it. Still other contractors have not been exposed to concrete tile at all. One topic that tends to unite these contractors against concrete tile is its weight.
It is imperative that concrete tile manufacturers address weight concerns head-on. We need to turn this perceived weakness into our greatest strength. Weight is the defining characteristic of concrete roof tile that makes many of its other benefits possible. We cannot tout our superior energy efficiency, our durability, our fire and hail ratings and then run from weight. These features and benefits are all tied to the amount of all-natural raw materials we incorporate into a premium, sloped-roofing product.
The first and most tangible benefit derived from weight is energy efficiency. When discussing energy efficiency, it is more appropriate to refer to weight as thermal mass. Thermal mass can be thought of as a product’s ability to store heat energy before allowing it to conduct through to the attic space (where HVAC equipment and ductwork are often housed). Therefore, the more thermal mass, the more heat energy stored. This means that tile, with a thermal mass more than double that of asphalt shingles or metal roofing, can delay the movement of heat into the attic. The attic temperature will be considerably lower as a result and this lower maximum daily temperature will occur much later in the day when energy use inside buildings is lower. A study at Oakridge National Laboratory showed that the results of this effect equated to an R value of 2. What does this mean for home and building owners? It means that they will experience lower energy costs and more comfortable living conditions.
It is also important to note that tile’s greater thermal mass allows it to provide energy efficiency beyond mere reflectivity. Most ratings agencies focus on reflectivity as it is an easy value to test. However, reflectivity’s benefits diminish significantly after a roofing material has reached its maximum thermal mass. This means that concrete tile's reflectivity is more valuable than the reflectivity on lower thermal mass products.
Another benefit of tile's weight is overall durability and longevity. One of the earliest examples of nanotechnology – the hydration process that occurs when Portland cement and water combine to create the glue that suspends the aggregate – produces one of the strongest materials known to humankind. Because concrete is so strong and the extrusion process used to make concrete roof tile is so efficient, tiles throughout the industry often pass the FM 4473 ice ball hail rating test. Without its weight and heft, it would be very difficult to withstand a two-inch ice ball fired at over 70 mph.
This kind of durability explains why tile roofs over 100 years old can be found around the world. According to an NAHB study of life-cycle costs for different steep-slope roofing products, a tile roof may last as long as three or four shingle roofs.
Concrete roof tile became a mainstay in the western United States in the 1980s due to its fire resistance, a quality derived from its density and weight. Because concrete roof tile is both thick and dense, it provides a roof surface that is impervious to heat. Obviously, there are considerations that need to be addressed at perimeters and transitions in order to prevent flying embers from entering the roof. However, the exposed field of the roof cannot reach temperatures that would cause it to combust or to cause any combustible materials under the tile to combust due to the heating of the tile. This makes concrete roof tile the superior choice for a Class A fire rated roof.
The benefits of concrete roof tile are numerous, and the average home owner may agree that it is a great choice for their needs, but they may still worry about the load it will place on their home. There are many misconceptions about the weight of concrete tile roofs. Factually, there is often little need for concern. Many homes in all regions of the US and Canada are already suitable to take the load of a tile roof and most others need very little in the way of framing upgrades in order to hold a durable tile roof.
A majority of homes in the last 30 plus years have been constructed with pre-engineered trusses. These trusses are engineered and certified to hold pre-determined loads. Whether 2”x 4” or 2”x 6” lumber, they often incorporate webbing, angled supports that break up the overall span of the truss. The addition of the webbing increases the trusses' load capabilities and often trusses that currently support an asphalt shingle roof are able to support a concrete tile roof. This can be determined by locating the home’s plans, going to the local building department, or it may even be determinable by referencing a stamp on the trusses themselves.
In situations where conventional framing was used or when the pre-engineered trusses are not yet capable of holding a concrete tile roof, an engineer can be contracted to produce a stamped report. The report will explain any framing deficiencies and propose upgrades that can be made during the course of the roofing project. Very often these upgrades are minimal and require little added cost.
Given the large number of substantial benefits provided by concrete tile roofs, it is time for the concrete tile industry to take its place among the most popular steep-slope roofing products. While weight is an important factor to consider, it should be recognized by homeowners and building owners as a benefit that makes concrete roof tile the most energy efficient, most durable, longest-lasting and most fire resistant roofing option available to them. It is up to the concrete tile industry to convince them that “Weight is Our Strength.”
Tyler Allwood is the Director of Business Development for Eagle Roofing Products and a member of the Tile Roofing Institute Government Relations Committee and FRSA’s Roof Tile Committee. Tyler was a roofing contractor in Florida prior to joining Eagle and served as President of the Sarasota/Manatee affiliate of the FRSA.
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