Several deck drainage systems have come to market in the last couple years that promise to transform the spaces below second-story decks into functional outdoor living areas. TimberTech first opened this category in 2005 with Dry-Space ( www.dryspace.cc), which consists of extruded vinyl drainage pans that fit between deck joists to channel water away from the area below. The pans slip into vinyl extrusions that clip onto the bottom edge of the joists, creating a clean finish ceiling for the space below. “We've installed dozens of these systems, and customers have always been very positive about them,” says Michele Moss of 1st Deck, in Kansas City, Mo. “It's been a good seller for us.” DrySpace is no longer the only option available. Shawn Carter, project manager at 1st Deck, has also installed DrySnap ( www.drysnap.com) and RainEscape ( www.rainescape.com) systems. “Everyone likes having that area [below an elevated deck] dried in,” Carter says. “DrySpace performs well once it's installed, but we find these other two systems to be a bit more forgiving.” If the framing is not dead-on, he explains, or the deck is framed in any configuration other than rectangular shapes, the TimberTech product can be difficult to install. Another drawback is that the material is sold in kits that cover either 120 or 170 square feet, which often forces you to overbuy for a single project. Both DrySnap and RainEscape can be purchased by the linear foot to match each job.

The DrySnap system consists of 8-inch panels that install entirely below the deck joists, and finishes out like beadboard ceiling. “We build a lot of unusual deck shapes,” Carter says. With DrySnap, it really doesn't matter how the framing above it is configured, as long as there is consistent support at 24 inches on center or less.

DrySnap vinyl drainage panels finish out the ceiling of a curved, second-story deck built by 1st Deck of Kansas City, Mo. The panels fit under the joists, allowing for any configuration of framing above them. Even better, Carter says, is the RainEscape system, which consists of flexible plastic sheets that get stapled between the joist bays and a series of drainage boots that channel runoff into a gutter. Because the material flexes, it can be cut and will conform to any framing configuration. It's intended to be covered by a finish ceiling below. “When it's done, you'd never know it was there,” Carter says.