Remember the old days, when homes were sturdy and built to last, and set on generous plots of land? Today's homes have evolved to cookie cutter houses built so close together you can barely fit a lawnmower between them. These semi-townhouses come with very little maintenance since their yards barely extend beyond the main structure. They do, however, come with unsuspecting risks.
Due to their close proximity to neighboring houses they might as well be town houses, but they aren't built with the same fire-safety regulations. Some are less than six feet apart, but at three stories high, a fireman wouldn't be able to lean a ladder far enough back to reach the second level. Climbing up the ladder with necessary breathing gear or carrying someone down the ladder is next to impossible.
A home ignited from a neighboring fire is known as an exposure fire. In 1993, in Loudoun County, VA, three new homes with six foot separations all caught fire before the firefighters could get there. In another instance, a house caught on fire and melted the siding of the neighboring house 10-15 feet away.
Experiments were done in 2004 to determine the length of time it would take for a fire to spread between two exterior walls six feet apart. This is typical for many new developments where homes are required to have only a three foot setback from the property line.
After igniting the first wall, it took 3 minutes and 42 seconds for the flames to break a window. After another 80 seconds, the adjacent wall had ignited.
In a second experiment, an extra barrier of Sheetrock was placed under the siding of each building, and in this case, the neighboring house failed to ignite. This learning could be applied when revising building codes, but in the US there is no single national building code; every jurisdiction has their own version, and apparently some have none at all.
In Southern California, an area plagued by wildfires, the building codes were tightened up to include fire-resistant building materials, in-home sprinklers and increased water flow for fire suppression. Fire-resistant landscaping methods were also implemented such as perimeter clearing of trees and brush. The reduction in loss of homes due to exposure fires more than justified the changes in regulations.
When shopping for a home located in close proximity to another, here are a few rules to keep in mind:
Be aware of the local code. Your local planning department should have a copy of the building code; section R302 describes the requirements for separations between dwelling units.
Face solid walls to your neighbors. Walls facing a neighboring home should be made of fire-resistant materials such as brick or stone and should not contain windows. An extra interior layer of fire-resistant material under siding can help slow the spread of fire.
Hire an inspector for a thorough check before buying a home situated close to another. When you're screening candidates, test their knowledge of exposure fires.
Is the roof made of straw, sticks or brick? Wood shake and shingles are a combustible building material. Look for Class A composite shingles that are rated for fire resistance. Other resistant materials include slate, terra cotta and metal.
If you're already living in a home located close to your neighbor, increase your safety by following these tips:
Remove combustible items. Anything sitting between the two homes that can easily catch fire should be removed. This may include lawn mowers, gas cans, rags, trash cans, firewood, sheds or yard equipment. Try to clear a minimum 7-8 space between homes.
Practice fire resistant landscaping methods. This involves getting rid of dead, dry plants, weeds, and replacing dry mulches with gravel or crushed rock. In April 2007 alone, 18 fires started in dry garden mulch in Loudoun County, VA.
Organize your neighbors. Help your community understand the risks from exposure fires and how to prevent them.