Living With Fire

Little Things Matter Most: Preparing Your Home for Embers from Wildfires

ember resistant home
This is an example of what makes a home vulnerable to embers. From top middle proceeding clockwise: 1) Tree canopies are too close together and too close to the roof edge. 2) Wooden gate attached directly to the wall allows high intensity fire to burn right up to the structure. 3) A woody shrub with dead material adjacent to the wall and the wooden fence could easily catch embers and spread flames to the home. 4) Another woody shrub with dead material, this time underneath trees, a textbook example of a ladder fuel. Also, the woody mulch would likely burn in an ember storm and spread to the shrub and the wooden fence. Photo source:

The Next Step in Maintaining Defensible Space

By Mitchell Danforth, Community Fire Resources Coordinator,
Trees Foundation

Summer is here, and as we all know, so is wildfire season. Often wildfires are depicted as an indomitable force that sweeps across the landscape, leveling all in its path like a lava flow, and the homes left standing are just lucky. However, there are many things that can be done to improve a home’s chances of survival, and most of them are quite small. It is said that “fortune favors the prepared”—this holds true for wildfire season. We need to set ourselves up for success independent of whether homes are defended or not. Decades of study and research have shown that the little things are actually the biggest factors in determining how resilient a home is to wildfire. The tiny details of home construction and property maintenance matter more than the construction materials themselves and become the Achilles’ heel if not addressed properly. The main threat is also tiny: embers.

Embers, though small, have enormous potential to cause fires. Often overlooked, these little pieces of burning material can travel up to a mile and still pack enough heat to start a fire where they land. While seemingly innocuous on their own, embers are generated by wildfires in such great numbers that they are often referred to as an “ember storm.” In a mass their heat output is quite high. Unfortunately, these embers can travel far from the main front of a wildfire, jumping containment lines and fuel breaks, starting spot fires and threatening homes. Often embers threaten a home long before the actual flames of a wildfire get there. So what can be done?

The particularly vulnerable areas for a structure are the roof (especially gutters, exposed rafters, and roof-to-wall intersections) and the space 0–5 feet out from the base of walls, as this is where embers tend to accumulate in the greatest quantities. Ensuring that these areas are adequately prepared is not only vitally important but relatively easy to accomplish. Many of the actions that can help your home in a wildfire fall into the category of common-sense routine maintenance that prevents things like rot and water damage. Not coincidentally, embers prey on many of the same areas of poor design or deteriorating material that are susceptible to damage in heavy rain.

Burning material, especially vegetation, gives off an immense amount of embers. Individually, these embers are relatively harmless (as demonstrated by the man in the foreground), but together they start spot fires wherever there is readily combustible material. Photo source:

Of the three “Defensible Space” zones, the 0- to 5-foot zone—also known as the “Ember-Resistant Zone”—has been identified as the most important for wildfire preparation. Combustible materials left next to a structure are typically more vulnerable than the structure itself and pose a much greater risk than embers alone. Leaf litter, vegetation, stored materials, and combustible furniture are some of the biggest culprits here, but fortunately all of them are easy to deal with.

A few tools and a little time can go a long way toward getting ready for the season. Following are some simple and low-cost things you can do to prepare for embers this wildfire season. Note: This material does not cover all aspects of wildfire preparation. This is not intended to be used as a comprehensive guide. For specific recommendations, look up the UC Cooperative Extension Publications, visit the CAL FIRE website, or consult your local wildfire safety and preparedness experts.

Clean Your Roof and Gutters

This is no longer just a fall-time activity! The leafy debris on your roof and in your gutters is a huge fire risk in the summer. Gutters, eaves, and roof-to-wall intersections are especially vulnerable; ignition of materials there can spread under your roof or siding. Even noncombustible roofing materials like metal or tile can be rendered ineffective if flames from the gutter get into the attic underneath. A leaf blower or garden hose are easy ways to get rid of debris; also consider installing noncombustible gutters and gutter guards.

Move Flammable Materials Away from Structures

Most of us have some clutter stacked up next to the walls of our house, garage, or shed. Not only is this unsightly, it’s actually a major liability. While even plywood walls are resistant to embers; direct flame and radiant heat from a burning pile of lumber, for example, is enough to compromise virtually any material. Make sure that your 0- to 5-foot zone is clear of anything that could combust, and store that stuff indoors where embers can’t get to it. That includes furniture, fuel, chemicals, toys, tools, grills, firewood, arbors, trellises, and practically anything made with wood or plastic. Lastly, your wooden fence acts like a fuse when it combusts, providing an uninterrupted pathway for flames to travel down. Cut the fuse before it reaches a structure by replacing that final 5 feet of wooden fencing or gate with metal.

Remove Dead, Woody, and Large Vegetation Within the 0- to 5-Foot Zone

Research has shown that plants immediately adjacent to your house are a major concern in a wildfire, even potted plants (especially in a plastic or wooden container). Plants located next to openings such as windows and doors are particularly problematic. New recommendations are to reduce vegetation to small, low to the ground, widely spaced, and well-watered plants with “hardscape” (non-combustible material such as rock or gravel) in between. Organic mulch (such as wood chips or straw) can readily ignite from embers and is no longer recommended within 5 feet of any structure. Mature trees are considered OK as long as they are clear of ladder fuels and pruned back from chimneys and roof edges. Finally, just like the roof, leaves and needles need to be cleaned up from the ground near structures on a regular basis.

ember resistant
An example of a well-prepared 0-5 foot Ember Resistant Zone. The area is made of noncombustible material and kept clear of debris. However, the 5-30 foot zone is problematic: notice how the groundcover connects the bushes and trees? Horizontal and vertical discontinuity between fuels is key to reducing fire behavior.” Photo Source:

Create and Maintain Defensible Space

This tried and true strategy for increasing the resiliency of your property remains vitally important. The objective here is not to stop a fire but to reduce its intensity, slow its rate of spread, and give firefighters a chance to defend the structures. Breaking up continuity of fuels vertically and horizontally is key to reducing intensity. Defensible space can prevent a wildfire from knocking on your door, but it doesn’t protect against embers landing in vulnerable spots. Additionally, make sure your yard is easy to access and maneuver through—this is important for all kinds of emergencies. Once established, maintaining defensible space is pretty easy.

Caulk and Plug Gaps Greater than 1/8 Inch in Siding and Eaves

Embers are often driven by strong winds and can find ways to lodge themselves in tiny spaces, causing fires in particularly vulnerable areas, such as cracks in siding and trim. A little time with a caulk gun can remedy this and ready your home for winter all at once. While you are at it, be on the lookout for signs of rot, as rotten material is more susceptible to ignition. If you have exposed rafters, seal up any gaps around them and the blocking; later on, consider enclosing your eaves with soffits.

roof and gutters
Roof-to-wall intersections are especially susceptible to accumulating debris and moisture, causing rot, which is more combustible than material in good condition. Ensure your roof is constructed properly with at least 6-inch metal flashing along the walls and is kept clean. Good roof care is important all year round! Photo source:

Install Skirting Around the Base of Structures

If the base of your house is open—as is common in post and pier construction—enclosure or “skirting” needs to be a top priority because embers can easily find their way underneath if unimpeded. Even plywood skirting is preferable to none at all, though noncombustible material such as metal roofing is recommended. Wood lattice (a.k.a. “decorative kindling”) does not count! The bottom 6 inches or more should be a noncombustible material, which will also help prevent rot. In the very short term, make sure the area underneath your house is cleared of all combustible materials down to mineral soil. If you have a deck or stairs, make sure the area underneath is also cleared down to mineral soil.

Make Sure Vents and Chimneys Are Properly Screened

While vents are necessary for your house, they also represent potential pathways for embers to get into your attic or crawl spaces. Make sure your screens are metal and have at least ⅛-inch or smaller openings or are otherwise rated to stop embers. Move combustible materials away from vents inside the home in case some embers do make it through. Your chimney should also have a metal screen, sometimes called a “spark arrestor,” with openings between ⅜ inch and ½ inch in size. Close your flue during fire season when not in use.

Have an Evacuation Plan Established before a Fire Starts

This one is very easy to put off, but it’s actually easy to do as well. Evacuation is unpleasant to think about, but the better prepared we are, the more time we will have to get to a safe place safely and leave behind a home that has a better chance of survival. Have a game plan, create a checklist (examples are available online), know where to go, and have multiple ways to get there. Also, make sure you know where to get official information in an emergency and that you are enrolled in emergency alert programs. Keep in mind that evacuation orders are given strategically to avoid bottlenecks and ensure that everyone has enough time to make it to safety; and know that embers cause spot fires that make a wildfire’s progress difficult to predict and contain. If there is an active fire in your area, be prepared to evacuate.

Finally, Support Your Local Fire Departments and Volunteer Organizations

Many Fire Departments, especially in small towns and rural areas, are staffed by volunteers and have a severely limited budget. Despite limited resources, these departments are relied upon heavily as the first responders for all sorts of emergencies, not just fire and medical. Community support and appreciation are vital for their continued operation. Donate, volunteer, and attend your local pancake breakfast or BBQ—every bit helps! Also, vote to support measures that fund your fire department, such as district formations and special taxes: consistent funding is key for long-term planning and investing in the things that really help VFDs best serve their communities. Also, your local volunteer organizations do important work in educating and preparing the community for wildfires. Fire Safe Councils and Firewise Communities are prime examples of organized groups—get in touch with them and help in their efforts.

For more information:


My name is Mitchell Danforth. I have been a resident of Humboldt County since 2010 and a member of the greater Garberville community since 2015.

My interest in wildfire began in 2007 when I worked as a seasonal wildland firefighter on a hand crew for several years. The experiences I had on the fire lines showed me the need for all of us to reevaluate how our communities interact with the land on which they reside. This is why I recently chose to join the Trees Foundation as their Community Fire Resources Coordinator, to help my community and others become more prepared for and acquainted with wildfire.