Utilizing fire safe materials and designs in your home is key to keeping your family and property safe. After serious wildfires, it can seem like flames randomly leapfrog through neighborhoods, leaving some homes unscathed alongside others that have been reduced to rubble.
In reality, homes have critical points through which fire can strike. With some advance planning and maintenance, you can increase the chance your house remains standing after wildfire. Use the Home Hardiness Checklist or the suggestions below on how to harden critical areas in your home.
| Critical Feature
|Roof||Fires that catch on roofs are difficult to extinguish. Furthermore, they are hard to see and can go un-noticed until it is too late. Class "A" roofing material will resist ignition even when struck by a barrage of embers.||Ignition-resistant Class "A" or Non-combustible roofing material (concrete tile, asphalt composition shingles, etc)|
|Vents||Embers can easily slip through crawl space or attic vents. Once through, embers can ignite debris and items stored inside the house, setting the home ablaze from within. In addition to using specially designed ember resistant vents, consider periodically checking your vents to clean out combustible debris such as leaves and pine needles. For added protection, make sleeves out of plywood to cover vents before evacuating your house.||Meshed covers with <1/4 in|
|Vegetation||Vegetation can work in your favor and against it. Plants close to the home, under eaves, in corners and near windows catch fire easily. On the other hand, trees and shrubs farther away from the house can serve as buffers against radiation, convective heat and flying embers. Consider also fire-adapted ornamental species with succulent leaves instead of combustible junipers and cedars. The smaller the plants the better, especially near windows and other critical fail points such as inside corners.||Clear vegetation away from house|
|Windows||Heat stress expands glass more quickly than the wood frame, breaking the glass. Tempered glass is much stronger than regular glass, so it provides more protection from breaking. Dual-pane windows distribute the heat more slowly and uniformly so even when the outer pane breaks, the inner pane may remain. As with vents, fabricate window covers out of ¾ -inch plywood or another fire-resistant material to cover windows before evacuating when a fire breaks out.||Dual-pane windows with tempered glass|
Combustible debris can build up in gaps and corners, creating targets for flying embers to ignite. Decks are also often adjacent to large windows or sliding glass doors, increasing risk of glass breaking and fire entering your house. Thicker desk are preferred as decks less than an inch thick can ignite significantly more quickly. Replacing deck boards can be expensive, but may be one of the best investments you can make. Fire tests have shown that any rated material (plastic, plastic composite lumber, fire-retardant treated lumber, etc) will resist fire as well as solid wood, but none better.
Thick (>1 inch) solid deck with smooth surface
|Siding||Good quality sheathing – which is installed underneath the siding – was a key to protecting the home’s studs. A wide array of non- combustible siding can be installed over the sheathing – such as stucco or fiber-cement siding. Combustible siding – such as wood panels and clapboard – should be carefully inspected annually for gaps, making sure that they are filled with a high-quality caulk to prevent hot embers from taking up residence and beginning to burn.||Non-combustible siding material|
|Gels||Fire gels while costly, can be applied on homes and surfaces to help existing material resist lighting on fire when struck by embers. These gels are fire resistant and often impregnated with water to help douse embers as they strike your house.||Fire Gels|
Resources for Builders
New homes built after 2008 have increased fire safety measures, but owners of existing homes should also consider making changes to improve their homes’ resistance to wildfire.
Furthermore, it is important to keep up to date with the changes to the codes and regulations to ensure home safety.
There is no perfect solution to designing a fireproof home. Design elements such as overhanging eaves and deck board spacing designed to reduce moisture damage to a house also creates opportunities where fire can establish a stronger foothold. It is important that these conflicting design issues in wood construction be considered for adequate long term performance.
- Quarles, S.L (2005) What is a Fire Safe Roof?, Home and Fire
- Quarles, TenWolde (2004) Assessing Attic and Crawlspace Ventilation- Implications for Homes Located in the Urban- Wildlife Interface, Woodframe Housing Durability and Disaster Conference
- Quarles, S.L. (2012) Window Failure During Wildfires, Insurance Institute for Business & Home Safety
- Quarles, S.L. (2005) Decks - Safe or Not, Home and Fire
- Quarles, Cool, and Beall, (2007) Performance of Deck Board Materials under Simulated Wildfire Exposures, International Conference on Wood-Fibre Composites
- Quarles (2010) Changes to California’s Building Code for Construction in Wildfire Prone Areas- Impact on Wood and Wood-based Materials, International Convention of Society of Wood Science and Technology
- IIBHS - Protect your Property from Wildfire
Information on this website was compiled by individuals at the University of California, Berkeley, and is based on the results from laboratory fire tests, observations made during post-fire assessments and input from those who are involved in firefighting. It is important to realize that no house is completely fire proof, but you can make it more fire-safe.
The goal of the information contained in this website is to provide information on how homes ignite and are destroyed during wildfires, and to provide guidance on changes you can make to your home and its surroundings to make it better able to survive a wildfire, and to also help you understand why these changes are important.
Embers, also called firebrands, are the principle cause of home ignition and loss during wildfires. Embers can result in ignition directly, or indirectly by igniting combustible vegetation or materials on or near your home that would result either flames touching your house or a radiant heat exposure that may break glass in a window, or otherwise threaten your home.
As can be seen in this photograph, information about your house has been separated into 1) the roof and roof edge, 2) the sides and attachments and 3) other combustible materials and vegetation on your property. Although you can look at each of these items individually, it is important for you to understand that when threatened by a wildfire, the survival of your home will depend on improvements you make to your home itself (both in terms of materials and design you have, and how well they are maintained), and the “residential fuels” that are on your property. “Residential fuels” include vegetation near your home, often referred to as your “defensible space” and other combustible materials such as fire wood piles and gazebos or other structures located near your home. Ignition of these residential fuels can result in fire spreading to and igniting your home.