My company installs ICC-ES Division 7 pedestrian traffic coatings. The ones we install are waterproof and qualify as Class A/1-hour fire-rated roof coverings, though most haven’t been evaluated for use as decking in a Wildland Urban Interface (WUI). They aren’t mentioned as an option to traditional cedar or composite decking in Steve Quarles’ recent Q&A about fire-resistant decks (Sep/Oct 2014), but I think they should be. I once saw a YouTube video where a firefighter described a wood deck as “organized kindling.” Indeed, a quick search of YouTube videos shows many a home and deck going up in flames after burning embers (simulated by “brands” in most fire testing) land on a wood deck. I’ve set my Google account to find news articles about deck fires, and almost every day I receive a new alert about a house or deck fire caused by a cigarette tossed into a planter or by coals dropped from a grill.

In fact, I have one client whose apartment building was firebombed by the rival gang members of a tenant. His deck over the garage and his second-floor walkways were protected by the concrete-based walking deck system I’d installed several years earlier, which the fire department credited with helping prevent the flames from spreading into living areas and for allowing time for the tenants to escape. Although there was extreme damage to the joists and plywood in the ceilings, the coating did not burn through.

It would be interesting to match several Class A/1-hour fire-rated pedestrian traffic coatings against redwood, cedar, and composite decks in actual ASTM fire testing. I’d bet good money that the coatings would come out on top, which is why I believe that they should be used instead of traditional wood or composite decking for any deck built in a WUI.

Bill Leys
Division 7 Waterproofing Consultants
Arroyo Grande, Calif.