The craftsmanship required to work with delicate, costly materials provides a lasting cachet in the custom home market. But with increasing focus on green building as well as low maintenance, interest is swelling in alternative products–especially those that can realistically capture the texture, color variation, and appearance of natural materials while delivering superior performance.
The small but growing category of synthetic roofing products caters to homeowners, builders, and remodelers who prefer renewable resources but want the look of slate or shakes. Even for those who are more interested in durability and longevity than in environmental friendliness, synthetic roofs can be a good choice.
Advanced materials and manufacturing technologies give the synthetic products better resistance to weathering, greater durability, and longer lifespans than real slate or cedar, according to manufacturers. "You emulate the natural material, but get performance and longer life over the natural product," says Charlotte, N.C.-based custom builder Jay Robinette, who used Enviroshake roofing on one high-profile project. "You're saving on potential callbacks."
Synthetic slate and shake products are manufactured from a variety of materials, primarily polymers and/or rubber along with fillers and modifiers. Although the products seem very similar, formulations vary among manufacturers.
"There are so many plastic or rubber compounds that can be utilized that to say they're all the same couldn't be farther from the truth," points out Brian Eberle, vice president of marketing and sales for Wellington Polymer Technologies, maker of Enviroshake.
The polymeric composition of most synthetic shingles and shakes generally includes advanced UV inhibitors and impact modifiers. Some products incorporate ingredients such as recycled rubber or plastic, mineral dust, or cellulose fibers, while others use virgin rubber and plastic.
The majority of the synthetic slates and shakes are backed by 50-year warranties. Most are UL-certified for Class 4 impact resistance, and many, but not all, also achieve a Class A fire resistance rating. Furthermore, some are rated to resist uplift in high winds.
Compared with natural shakes and slate, synthetic roofing products offer simpler installation and generate less waste. They come in several sizes to minimize the need for cutting, and because the products are of consistent quality, no pieces have to be culled because each one is usable.
Synthetic slate in particular is easier to work with than natural slate; it is lighter in weight and does not require a reinforced roof. Adding 10 percent to 20 percent to an order is typical for real slate to make up for breakage during shipping and installation. But synthetic slates are more flexible and durable, and breakage is virtually nonexistent, manufacturers say.
Both synthetic slate and shakes can be cut using standard wood or stone-cutting saws; some manufacturers claim their products can even be sliced with a utility knife. With most synthetic roofing products, the surface color goes all the way through, so the appearance does not change and there is little need to hide cut edges. They also can be installed using pneumatic nailers, unlike real slate and cedar shakes.
Shades of Green
The question of whether synthetic roofing products have green characteristics must be answered on a product-by-product basis. They are all polymer-based, which means they are made from a petroleum-derived material. Some synthetic slates and shakes are manufactured using recycled content and some are not. Those that contain recycled content typically use high-quality post-industrial materials from automotive and other industries, but a few incorporate a small amount of post-consumer content such as recycled tire rubber.
A long life expectancy–supported by extensive industry testing for UV resistance, low water absorption, and resistance to freeze/thaw cycles–means that roofs don't have to be replaced every 15 to 30 years, and there are fewer repairs during the roof's lifetime.
Even products that do not use recycled content can be considered somewhat green because they are polymer-based and a majority can be recycled at the end of a roof's lifespan.
It may be difficult to sell some clients a polymer-based roof without firsthand experience of the product, so architect Wayne Visbeen of Grand Rapids, Mich., put it up on his own home. "I wanted to use this particular roof on several projects this year, but it's very hard to recommend that a client use an unproven product," he says. "So I put it on my house."
Self-educated consumers looking for cutting-edge products will continue to be driving forces behind the slow but steady growth of the synthetic roofing category. "It seems that the credibility is beginning to find a place and people are becoming more and more secure with polymer-based shingles designed by chemists and engineers," says John Humphries, president of DaVinci Slate and shake maker DaVinci Roofscapes.
–This story first appeared in Custom Home magazine.
DaVinci Roofscapes. Exhibiting deep surface graining and a thick profile, DaVinci Shake roofing features two layers of UV protection to prevent fading and damage, according to the firm. Four different shingle widths create the random appearance of a real wood shake roof, the maker says. The product is Class A fire rated and Class 4 impact rated.
Royal Building Products. Manufactured from a proprietary polymer compound, Dura Slate roofing tiles look like slate, but install easily without the structural requirements of the real thing, says the maker. Dura Slate will not dent, chip, or spall, the company says, and achieves UL Class A fire resistance and Class 4 impact resistance.
EcoStar. Designed to replicate the smaller size and appearance of eastern United States slate roofs, Majestic Slate Colonial tiles are made from a formula that includes recycled rubber and plastic. The flexible, durable tiles come in nine colors. They are rated for Class 4 impact resistance and Class A fire resistance, and come with a 100-mph wind warranty.
Wellington Polymer Technology. Utilizing a composite of post-industrial plastics, recycled rubber elastomers, and cellulose fibers, Enviroshake replicates the look of a silvered taper-split cedar shake roof, the maker says. Enviroshake, which carries a Class C fire rating and Class 3 impact rating, is mold-, mildew-, and insect-resistant, the maker claims.
Tamko Roofing Products. Lamarite Slate shingles are made from a mineral-filled polymer and are molded to exhibit the textures and contours of natural slate, according to the manufacturer. The Class A fire rated, Class 4 impact resistant shingles come in four colors. They feature spacer tabs, exposure marks, and designated nailing areas to ease installation. 800-641-4691. www.tamko.com.