Wood, as well as plastic and plastic composite products, is combustible, so the best way to improve its performance in a wildfire is to avoid conditions where it could receive a flame impingement exposure. Examples of vulnerable conditions include combustible vegetation or firewood located adjacent to or under the wood or wood-based component. Using larger wood members (greater than 6 in. by 6 in. in cross section) will improve performance because of the ability of wood to develop an insulating layer (the "char" layer) as it burns. Like a campfire, wood burns most vigorously when the members are small and the orientation of adjacent pieces allows re-radiation between burning surfaces. Wood with pressure-impregnated fire-retardant chemicals is available for exterior applications. Such fire-retardant treatments approved for exterior applications have been evaluated for the leach resistance of the chemical treatment.

Browse related FAQs by tag: surviving wildfire, beforefire