How to Get Flame Retardant Roofs and Walls

A house destroyed by fire can represent a devastating loss, even if everyone inside escapes with their lives. So many memories can be be carried off into the winds by the conflagration. You can limit the damage by having your roofs and walls fireproofed.

Difficulty: Moderately Easy

Instructions

1. Consider a fire retardant varnish or coating for your roof. For some locales, this is the minimum required by local building codes. Many localities won’t allow new roof construction unless the shingles have been chemically treated under pressure. To find a coating for an existing shingle roof, look at www.fireretardansinc.com. The company also offers a toll-free hot line for consultation.

2. Investigate mission-style tiles. They offer good fire protection but they haven't been used much in the U.S., except in the Southwest and Florida. Traditionally the tiles are made of clay, which doesn’t burn, decay or corrode. The tile is fired in a kiln to harden it and limits its ability to absorb water. The cheapest tile, from Mexico, is unglazed and can absorb up to a fifth of its weight in water, which make this tile unsuitable for anyplace but a hot, dry climate. Soaking and freezing will cause it to crumble. The best tile is made of premium ingredients, glazed and fired. It absorbs only 3% of its weight in water and is designated as vitreous tile. Top end tile comes with a 50-year warranty. In Europe, some tile roofs are hundreds of years old, yet still doing well. Tile is now available in flat shapes as well as the traditional split cylinder forms.

3. Weight the advantages of concrete tile for your roof. Concrete is a mix of sand, cement and aggregate, which has been cured chemically. A ribbon of concrete is extruded on a machine and cut at intervals to make tiles. Like clay, it doesn’t corrode or rot and needs little maintenance. It also absorbs less water than even vitreous clay tile and is now available in a range of shapes and sizes.

4. If you have a typical asphalt shingle roof, coat the roof with an 1/8” layer of Portland cement mixed with acrylic latex. A less expensive method, which is probably better suited for a cabin in the woods than a neighborhood home, is to glue aluminum foil to it. Foil is fragile, so it would be hard to walk on the roof after foiling it. You might also want to paint it with RV paint, so the roof is less of an eyesore.

5. Use fiber cement siding as a fire resistant covering for an external wall. This siding looks like wood, but it is made from a blend of cellulose fiber, cement and sand that’s been cured in an industrial pressure cooker to add strength. It doesn’t rot and is termite proof. You can buy it with a factory applied top coat, so that you won’t have to paint it for at least 5 years.