Embers are the most common cause of ignition for both site built and manufactured homes. Embers are light enough to be blown through the air and can result in the rapid spread of wildfire by spotting (in which embers are blown ahead of the main fire, starting other fires). This wind-driven rapid spread scenario was observed, for example, in the 2017 Tubbs Fire in Santa Rosa and in the 2018 Camp Fire in Paradise. Should these embers land on or near your house, they can ignite nearby vegetation, accumulated debris, or enter the home through openings or vents. Recent research indicated that two out of every three homes destroyed during wildfires were ignited either directly or indirectly by wind-dispersed, wildfire-generated, burning, or glowing embers and not from the actual flames of the wildfire. “Indirect ignition” implies either a radiant heat and/or direct flame contact exposure to the building from the combustible item ignited by the embers.
Near-home ignitions can subject some portion of a house to either a direct flame contact exposure (where the flame actually makes contact) or radiant heat exposure (the heat felt when standing next to a campfire or fireplace). If the fire is close enough to a combustible material, or the radiant heat is high enough, an ignition will most likely result. Even if the radiant exposure is not large enough or long enough to result in ignition, it can preheat surfaces thus making them more vulnerable to ignition. In most mobile home parks the homes are sited relatively close together. This can make mobile homes more vulnerable if adjacent homes are ignited by wildfire.
All homeowners should take action in four areas to reduce wildfire risk.
First, prepare yourself and your family. Make a disaster plan, sign up for alerts and warnings, know your evacuation routes, pack a go bag, make a plan for your pets.
Second, create defensible space around your home. The first five feet around the home should be clear of all combustibles. In most mobile home communities in Marin, homes may be located close to each other. When there is sufficient space between homes, be sure to clear dead grasses, weeds, plants and foliage within 30 feet from your home. Limb up trees and create space between plants. Do not use highly flammable mulches like gorilla hair. Any kind of flammable mulch product (i.e., all bark mulch products) should be avoided in areas close to the home.
Third, take action to harden your home. Mobile homes sometimes have decks which must be protected from embers. There should be no combustible materials under decks or the home itself. Make sure decks are properly screened (from the edge of the deck, vertically down to the ground) with corrosion resistant ⅛-inch mesh or smaller metal screening to minimize ember intrusion in the area under the deck. If there is a fence, make sure there is a noncombustible section that connects to the home. That could be something like chain-link, hog wire, or iron. The immediate solution, if you are evacuated in the event of a fire is to prop the gate open to create a break in the fence. If you think of the fence like a candle, we want to break the wick so it can’t burn any further.
Make sure the area around the skirting of your home is tidy and free of brush and debris. Keep the roof clear of trash and leaves.
Fourth, consider becoming a firewise community. Mobile home parks tend to be community oriented. Neighbors helping neighbors is a great way to prepare.