“Underdecking”, or “dry-deck”, refers to any product either in the decking, or under the decking, that creates a dry space underneath the deck area.
Underdecking and dry-deck products available include:
- Deck boards that feature built-in “gutters” in the interlocking board edges to drain water off the deck
- Weatherproof strips or inserts that are placed in the grooves of grooved deck boards for sealing the space between boards
- Panels installed into snap-in brackets attached to the underside of the frame, or between framing members
- Membrane(s) draped between and across deck joists, underneath the decking, that drain and channel water down the joist bay
Generally, underdecking is installed to have a nice, dry patio space or storage space underneath the deck. Underdecking might also be installed to add a finished look to the underside of the deck frame.
