In a past job managing condo associations, I spent a lot of time dealing with damage caused by leaks in decks over living spaces. The damage was often quite spectacular. In one case, a seemingly minor flashing error led to rotted framing below eight decks. It cost $114,000 to repair the decks and structural members. That episode convinced me there was a future for contractors who knew how to properly waterproof decks, so I went to work for a coating company. A few years later, I opened my own deck waterproofing business in Arroyo Grande, Calif.

There are about a dozen cementitious waterproofing systems that can be applied over wood framing. They are distributed primarily in the West, a region where there is significant demand for fire-rated waterproof decks. We use a product called Desert Crete (Hill Brothers Chemical Co., 800/994-8801, desertbrand.com), because its maker has been in...

or Register to read the full article.