Apr 1, 2020
Slate roofs are beautiful. They carry the patina of history as a go-to material for centuries for topping off homes, churches, government buildings, and apartments. Homeowners love them for their attractive appearance and the character they add. Yet slate can be expensive, heavy, and difficult to install. It must be quarried and transported to manufacturing facilities, resulting in high levels of energy consumption before being applied to rooftops.
Enter synthetic slate tiles. They have many advantages over real slate, from installation to the ability to be recycled. Yet, are they a green application for roofing? A debate rages in the roofing industry over synthetic slate tiles. Here’s a closer look at the issues.
Synthetic slate roofing looks like authentic slate roofing, except it’s composed of plastic and rubber materials. Manufacturers of synthetic slate roofing offer a wide variety of styles that fit nearly any house, from contemporary to French Colonial.
Faux slate comes in various materials, including plastics, polymers, clay, fiber cement, rubber, steel, and asphalt. They have different characteristics, price points, strengths, and weaknesses.
Plastic and polymer composite manufacturers mold individual slate tiles with ridges to look like natural slate. Recycled rubber and plastic sometimes form the basis of rubber slate tiles. Steel roof tiles are shaped like slate roof tiles but have less texture. Asphalt manufacturers offer premium shingles that share a textured attribute with slate.
In general, synthetic slate roof manufacturers and installers say they cost less to install and last much longer than authentic slate and other roofing materials. They maintain a good appearance for years, say advocates for synthetic roofs. More roofing companies can install them compared to slate, which demands a higher level of expertise.
Authentic slate proponents say no one will ever mistake synthetic slate with the real thing. Synthetics can curl, crack and disintegrate, especially in harsher climates. The flexibility of rubber and plastic means curling and cracking can occur, sometimes allowing water to seep into attics of synthetic roof owners. Tiles have discolored or faded in just a few years.
No, synthetic slate weighs much less than slate, allowing for simpler and faster installation, even by handy homeowners. Transporting tiles costs less because synthetic tiles weigh a quarter of natural slate. Installers can nail synthetic tiles into place with standard roofing nails and pneumatic nail guns. A utility knife can cut tiles. Authentic slate tiles need heavy nails and can be challenging to cut and shave. Roofers installing slate often require hiring specialized installers with more expensive skill sets.
No, the tiles are less expensive, as is the installation. Synthetic slate roofs cost roughly about $9 to $12 per square foot, installed, depending on where you live. Real slate roof installations cost $22 to $43 per square foot. Compared to other conventional roofing materials, synthetic slate roofing falls in the middle, being less expensive than real slate and clay tiles but more expensive than asphalt and architectural shingles.
Manufacturers claim they last longer for several reasons and offer 50-year warranties, with some claiming they can last 100 years. Materials used to produce the tiles are combined with ultraviolet inhibitors to reduce sun damage. However, most synthetic slate products have been in the marketplace for less than 20 years. Critics charge that they begin to look a bit aged after just a decade, with chipped and discolored panels. Over time, we will gain a clearer picture of the longevity of synthetic slate tiles.
Many synthetic slate models come certified for Class 4 impact resistance from Underwriters Laboratories. That’s the highest level that roofing materials can achieve, and this will help increase the resiliency of your home. Many synthetic slate roofs have elements and designs to mitigate storm damage.
Many synthetic roofs have Class A fire ratings, the highest level. The tiles do not create burning particles and embers that could spread fire to the rest of a roof and have no dangerous flammable characteristics.
These features make synthetic slate roofing a great option when considering the fire resistance of your home. Some synthetic roofs have Class B or C ratings. To increase that rating, contractors can add a layer of fire retardant material underneath synthetic tiles that will raise the project's cost.
Yes. Often, recycled materials form the basis of faux slate roofing products. Euroshield products, for example, are composed of recycled tires. Another product, Enviroslate, by Enviroshake, is composed of 95% reclaimed materials. In this case, the composition is proprietary, and therefore the materials included are not publicized. If you are thinking of pursuing LEED Certification, this 95% recycled content will aid in achieving LEED credits for recycled content.
Typically, synthetic tiles with recycled materials use recycled plastic, rubber, plastic, cellulose fibers, and mineral dust. Manufacturers use high-quality post-industrial waste rather than content from consumer products.
Many synthetic slate manufacturers produce their products in North America. Being able to source materials, recycle them, and make the product locally has many environmental advantages. These include reducing waste to landfills, reducing the carbon required for transportation, and possibly achieving further LEED points if you live within a 500-mile radius of the manufacturer.
When removed, synthetic roofs can be recycled. Roofing materials contribute 5 percent of the waste stream of landfills, a not insignificant figure. Real slate is not renewable and cannot be recycled.
As noted, synthetic tiles not as cheap as other roofing options. Not all models have Class A fire ratings. The industry suffered from a few fly-by-night companies, leaving customers with worthless warranties. And speaking of warranties, many industry professionals question the 50-year length since synthetics are relatively new. No one knows what they will look like after five decades of weather abuse.
Work with a roofing contractor and find out from the company if they have installed slate and synthetic slate roofs in your neighborhood. Check them out. Can you tell the difference? Now study manufacturer websites for more information and contact local distributors to gather samples. That won’t be easy, but holding real shingles in your hand and matching them to your home’s exterior will help you make the right choice.
Many reputable companies sell in this market. Plastic and polymer firms include Authentic Roof, Brava Roof Tile, DaVinci Roofscapes, Enviroslate by Enviroshake, Polysand, and Titan Roof Systems. Rubber manufacturers include EcoStar and Euroshield. Slate Select offers fiber cement shingles, and Certainteed offers metal, slate look shakes.
Based in St. Paul, Frank Jossi is a journalist, editor and content strategist. He covers clean energy in Minnesota for Midwest Energy News and writes frequently for Finance & Commerce. His work has appeared in more than 70 local, national and international publications.