Quick Answer: Slate tiles are the best fire-resistant roof for your home, followed by clay and concrete tiles, then metal. Most residential roofs aren’t equipped to support the heavy weight of slate or concrete tiles. Metal, on the other hand, is light-weight.
What Does ‘Fire-Resistant’ Mean?
Before we discuss the best fire-resistant roof for your home, we need to know what ‘fire-resistance’ means. It’s good to keep in mind that ‘fire-resistant’ is not ‘fireproof’. According to Surviving Wildfire, in order for a roof to be considered Class A fire resistant, fire cannot penetrate through the roof into the attic. Take asphalt shingles, for example. Most asphalt shingles have a Class A fire-resistant rating. Class A is the highest fire-resistance rating. For a certain period of time and at a certain heat intensity, asphalt shingles will resist catching fire. However, after so long, or with increased heat, they will catch on fire and burn, and melt. Asphalt shingles have asphalt in them. Asphalt is a form of petroleum. Petroleum burns.
Natural slate tiles, on the other hand, are also rated Class A. Slate is rock. Rock does not burn nor will it melt. Neither does concrete or clay. Metal roofing also doesn’t burn.
What Are The Roof Fire Classifications?
UL measures and tests, among other things, how resistant roof coverings are to fire. They rate different roof coverings, such as asphalt shingles, on a scale from Class A to C, and Unrated. Class A roof coverings are effective against severe fire test exposures, Class B against moderate fire tests, Class C against light fire tests. An Unrated roof is the most vulnerable to fire. An example of an Unrated roof covering would be untreated wood shake. Dry, untreated wood is the most vulnerable to fire. Campfire, anyone?
These fire test exposures are simulated and originate from outside the home. In other words, how well will your asphalt shingles protect your home from an approaching fire, for example, if a burning brach lands on your roof?
Causes of Roof Fires
Roof Leaks
There is electrical wiring in your attic. A leak in your roof can allow water into your attic. Water in contact with electrical wiring can create sparks. Sparks cause fire. Your roof protects your house from outside fires, not from inside fires. If you notice a stain on your ceiling, have your roof and attic inspected immediately. A stain on your ceiling is a sure sign you have a roof leak. Other roof leaks signs include missing asphalt shingle granules, missing roofing materials, cracked or damaged roofing material.
Insulation
Insulation itself does not cause roof fires. Improperly installed insulation does, however. Insulation installed too close to HVAC vents can overheat the insulation and ignite it or other materials. Insulation covering electrical wires or electrical boxes can cause sparks. If you’re buying a used home, be sure to have it inspected, and make sure the inspector checks for these potential problems.
Roof Coverings
Some Class A fire-resistant roofs are better than others. Untreated and worn-out wood shingles or shake are the least fire-resistant. Although most asphalt shingles are Class A fire-resistant, as mentioned above, they still have asphalt in them. If you have wood shingles or wood shake, either have them replaced with a more fire-resistant roofing material, or get them treated immediately. If you have a worn-out asphalt shingle roof, again get it replaced with a new fire-resistant roof right away. A metal roof with a fire-resistant underlayment not only makes your roof fire-proof, it’s also the coolest roofing material for Colorado.
Dirty Chimney
Chimney fires are among the most common causes of roof fires in Colorado. As you use your fireplace, creosote builds-up on the inside walls of your chimney. Creosote is flammable. Have your chimney cleaned by a professional chimney sweep at least once a year, before you light your first fire of the Fall or Winter. A good chimney sweep will also inspect your chimney while they’re in there to look for damage or cracks. If they find anything, get it fixed right away.
Dirty Roofs
Another common cause of roof fires in Colorado is airborne embers. Embers come from as close as your neighbor’s chimney or a wildfire miles away. Embers landing on dry leaves or branches on your roof can catch fire. Inspect your roof and gutters in the Fall after leaves have fallen, and again in the Spring to remove any debris that might have collected. Give your roof a fighting chance against roof fires by keeping it clean.
The Best Fire-Resistant Roofs for Your House Ranked:
- Slate Tiles
- Concrete or Clay Tiles
- Metal (standing seam, and stone-coated metal shingles and tile)
- Asphalt Shingles
- Treated Wood Shake or Shingles
Slate Tiles
Slate roofing tiles are basically rock. They are made from sedimentary rock of volcanic ash and clay. Slate roofing tiles are mined from quarries and are extremely durable, waterproof, and fireproof. Rock does not burn. Slate roofing tiles carry a Class A fire-resistant rating. Slate roofing tiles are among the most fire-resistant roofing materials available today. Although they are among the most expensive, initially, they are among the least expensive in the long run. This is because they often last 70+ years. Slate tiles are also among the heaviest roofing materials, along with concrete and clay tiles.
Concrete Tiles
Concrete tiles, like slate tiles, do not burn. They carry a Class A fire-resistant rating. They are made from sand, cement, water, and iron oxide. Coloring agents are added to give them their unique colors. While the mixture is wet, it’s pressed onto steel molds to give them their unique looks. Concrete tiles can resemble barrels, slate, wood thatch, wood shake, or even asphalt shingles.
Concrete tiles, like slate tiles, are expensive and heavy. However, like slate, they often last a lot longer than, for example, asphalt shingles. Which makes concrete tiles lesser expensive over their lifetime.
Clay Tiles
Like slate roofing tiles, clay roofing tiles are a natural roofing product. They clay is mined, mixed, and stored for a period of time. It’s then pressed and cut into blocks. Pressed again, formed and trimmed to their verious shapes. Finally, the tiles are dried and baked. Like concrete roofing tiles, clay tiles are formed into many shapes. Traditional shapes include Romano pans, S tiles, and barrels.
Clay, naturally, does not burn. This makes clay roofing tiles very fire-resistant. Clay roofing tiles carry a Class A fire-resistant rating. They are, however, somewhat fragile. They do not stand-up to large hail stones or being walked on.
As with slate and concrete tiles, clay tiles are heavy. If you are considering replacing your asphalt shingle roof with slate, concrete, or clay tiles, your home will almost certainly require additional structural support.
Metal Roofing
Metal roofing products also carry a Class A fire-resistant rating. They include standing seam, and stone-coated metal shingles and tile. As with slate, concrete and clay tiles, metal does not burn. What’s more, standing seam metal roofing also helps to lower your cooling bill during the hot months. This makes it the coolest roofing material. Metal roofing products aren’t as expensive as tile, yet lasts as long, if not longer. Metal roofing is fire-resistant, if not fireproof with the addition of a fire-resistant underlayment. It also has a cooling effect during the warm periods. Could standing seam metal roofing be the overall best residential roofing material?
Asphalt Shingles
Most asphalt shingle manufacturers make Class A fire-resistant shingles. This includes, among others, Owens Corning, CertainTeed, and GAF. Asphalt shingles are among the shortest-lived roofing products, however. Which makes them the more expensive long-term. They are among the least expensive, initially, though. Asphalt shingles also contain asphalt, which will eventually melt and burn. Which is why we list asphalt shingles lower on our list of the best fire-resistant roofing materials for your house.
The Least Fire-Resistant Residential Roofing Material
Wood Shake
Right out of the box, wood shake roofing, such as cedar, isn’t fire-resistant. Wood shake needs to be treated with a fire retardant in order for it to be fire-resistant. There are three different fire retardant treatments available. These treatments costs extra money. A wood shake roof is already expensive. A high quality wood shake roof almost costs as much as a new metal roof (standing seam or stone-coated metal shingles or shake) at around $8.50/sf. Since a metal roof easily outlasts wood shake, it’s more cost-effective to have a metal roof, be it standing seam or stone-coated metal shingles or tile.
How to Choose the Best Fire-Resistant Roof
The best fire-resistant roofing material is the one you can afford or the one that you’re allowed. Not everyone can afford natural slate tiles. Not every roof can support them, anyway. However, if you can afford tiles or metal roofing, and if your home can support them and HOA allows it, these are the best fire-resistant roofing materials. As mentioned above, rock, concrete, and metal doesn’t burn.
Standing seam metal roofing might be the perfect sloped roofing material. It’s highly fire-resistant. It’s the coolest roofing material for Colorado. It lasts longer than most other roofing materials, which makes it cheaper in the long run. Although it’s more expensive initially, our financing makes it affordable.
If you live in a neighborhood whose homes all have asphalt shingles, your HOA might not allow you to have a standing seam metal roof. If this is your case, stone-coated metal shingles or stone-coated metal tiles might be the best you can do. Check with your HOA or city ordinance.
If you have no HOA, or if your HOA is not concerned, congratulations! Go with a metal standing seam roof with a fire-resistant underlayment. Embers and snow will slide right off your roof, and your new metal roof will help lower your Summer cooling bill 🙂