Friday, June 09, 2006
Make your home fire-resistant
By Ann Robinson and Annie Vernon
This is a beautiful time of year. The mountains and foothills are awash in green grasses and vegetation and for a brief moment it feels more like the lush Northwest than the arid Great Basin.
But already the desert heat is turning the first greens of spring to the dry yellows of summer, and we find ourselves approaching another fire season. There are steps you can take when remodeling or building anew to help guard the exterior of your home against marauding flames from a wildfire or neighboring house fire.
The primary ignition sources for exterior fires are flames, radiant heat and airborne firebrands. The most vulnerable areas of your home's exterior are the roof, soffits and windows. Though beautiful, wood shingle roofs are especially hazardous. They make all-too-productive tinder for fire, and once aflame, airborne shingles can be a hazard to surrounding structures. Instead, consider using more fire-resistant materials such as Class A asphalt or fiberglass shingles, metal roofing material, terra cotta tiles or lightweight concrete composite materials.
Keep your roof free of leaves and debris that may accumulate in valleys or gutters and become fuel for a fire. Chimneys and stovepipes should be covered with a nonflammable screen, as should attic and underfloor vents, to prevent sparks from entering your home.
A soffit is the horizontal part of your roof that overhangs the exterior walls. Vinyl is often used in this area because it is relatively inexpensive and maintenance-free. However, vinyl will quickly melt and allow fire to penetrate into your attic or roof. For better fire protection, soffits should be made of a noncombustible material or a minimum of 1/2-inch thick wood sheathing.
Windows are a vulnerable point in the envelope of your home. Heat from a fire will cause glass to fracture in just minutes. Double-paned glass and tempered glass give more protection than single-paned. Smaller panes will hold up better than larger ones. You can also add operable, nonflammable shutters for extra protection.
For exterior cladding materials, brick, stucco and man-made products, such as cement fiber board, are better at surviving flames than real wood. Foundations are usually built of fire-resistant concrete or masonry block. The further a foundation extends above the vegetation, the more protection you will have from a spreading ground fire. Also consider using metal doors instead of wood ones.
Well-planned landscaping will also help minimize the exterior fire danger to your home. The primary goal is fuel reduction. Fire experts advise having four zones radiating out from your home. Zone 1 (closest to your house) should be well-irrigated and include carefully spaced, low flammability plants. Zone 2 should also be well-irrigated and have low-growing plants. Zone 3 can include trees that are well-spaced with vegetation kept low around them. Zone 4 includes natural vegetation, and even here you should selectively prune and remove highly flammable vegetation.
Keep all shrubs and trees properly pruned, with the lowest branches six to 10 feet above the ground. Dispose of debris promptly and keep the lawn mowed. Store firewood away from the house and separate wood fences from the main structure.
Few things are as devastating as a house fire. Wise planning will help to minimize the danger to your home and those around it. As always, we welcome your home architect design questions at firstname.lastname@example.org.