Is Your Home Prepared for a Wildfire?

Decks can be ignited by wildfires via flame contact (usually from below) or ember attack (usually from above). Burning decks will expose the house to long-term flame impingement, which could ignite siding and/or shatter windows. If the decking or siding is highly combustible, flames may spread to the eaves. There are several factors that can contribute to deck ignition.

Deck enclosing is often recommended by wildfire guides, but it may not always be the best option. The benefits of enclosing your deck are minimal if you are not storing combustible materials under your deck, while moisture-related degradation can become problematic. The gaps between deck boards also play an important role in ignition. A gapped-board deck will be less likely to have flames spread from its lower to upper surface if the deck boards are tightly installed. It would, however, be a bad detail due to the increased risk of water accumulating in the joints, causing fungal decay. The deck's distance from the ground also matters. Debris under decks that are close to the ground are generally more difficult to remove and could pose a fire safety risk.