It is not uncommon that replacement tiles will not be an exact match. While matching the color is desirable, matching the profile is essential. Reclaimed tile yards can often be a source of "good matches" particularly if the tile roof was installed some time ago and the tiles have been discontinued.

To protect the investment in the roof and prevent potential problems, a roof should be regularly inspected. If it is necessary to walk on the roof, soft-soled, non-slip shoes should be worn; it is advisable to step only on the lower portion of the tile where one tile overlaps the other, referred to as the head lap. For best results, professional roofers experienced with the unique features of tile roofs should perform any necessary maintenance and cleaning.

Sustainability
Concrete roof tiles are manufactured from natural materials: sand, cement and water. As a result, concrete roof tile is more environmentally friendly compared to other roofing products such as asphalt composition shingles or metal roofing. Old roof tiles can be recycled to create new tiles and other products. Not only does tile's less frequent replacement translate to lower life cycle costs for the consumer, it represents an overall reduction in the use of energy and natural resources.

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System has become the accepted measure for sustainable development for green building construction within the USA. Concrete roof tile can be used towards achieving LEED credits in several new construction or major renovation categories.

For dramatically increased energy savings, manufacturers now offer solar panels integrated with roofing tiles. One aesthetically pleasing option that has shown promise is pre-engineered photovoltaic modules interlocked with roof tiles or other roofing materials. In a hot, sunny climate, a 200-square-foot such system has been shown to generate some 70 percent of the power for a 1,500-square-foot home.

Cool Roof Issues
According to the U.S. Department of Energy, over 90 percent of roofs in the United States are dark-colored. Not surprisingly, a black roof has been shown to have a surface temperature of 190 ?F, while an identical white roof in the same setting will be just 110 ?F. Studies by Lawrence Berkeley National Laboratory and Florida Solar Energy Center show that light-colored "cool roofs" result in up to 40 percent energy savings, generating an estimated annual savings of $750 million in utility bills. A cool roof reflects and emits the sun's heat back to the sky instead of transferring it to the building below. Coolness is defined by two properties - solar reflectance and thermal emittance. The combined ratings of these two properties are calculated into a solar reflectance index (SRI) from 0 to 100. There are currently two national cool roof rating systems: the EPA's Energy Star Reflective Roof Program and the Cool Roof Rating Council's Product Rating Progam.

As mentioned previously, there is a LEED credit for roofing materials with a SRI 29 or greater. Striking a balance between reflectivity and aesthetics is at times a design challenge for architects.

As architects strive to get to an aesthetically pleasing cool roof, coating manufacturers are experimenting with coating tiles to boost reflectivity. Some coatings burn off in a couple of years and the peeling tiles can become a maintenance issue. After a period of time the functionality of the coating can be questionable. The Cool Roof Rating Council is currently conducting studies to determine how much reflectivity various coatings still contain after a threeyear period. Concrete roof tile manufacturers are taking another approach of experimenting with tile additives and testing their capabilities as an option for increasing roof tile's reflectivity.

 

LEED Points for Concrete Tile

 

 

While solar reflectivity is a worthy goal, it's important to bear in mind that by its very installation, tile can keep energy costs down. Concrete tile is one half inch thick and it's installed with an air gap beneath the tile and the roof, which means it takes a lot longer for the attic to heat up compared to other products that sit directly on the roof. A 2007 Oak Ridge National Laboratory study found that tile roofing's mass, reflectivity and air ventilation underneath the tiles cut the transfer of heat by at least 50 percent, versus an asphalt shingle roof.

Architects interested in further information on tile roofing's green benefits, including life cycle cost, recycling, reflectivity and sustainability can contact the Tile Roofing Institute at  www.tileroofing.org.