Apply Joist Tape/Waterproof Membrane

What happens here

After the main substructure is built, apply a protective joist tape or waterproof membrane (like Grace Ice & Water Shield) to the top of all joists. This membrane acts as a barrier, preventing moisture from seeping into the wooden joists and significantly extending their lifespan. The tape is typically self-adhesive and applied directly over the joist surface. This step is crucial for the longevity of the deck, especially when using composite decking that may not fully protect the underlying wood.

Goal: Protect the wooden joists from moisture and enhance deck longevity.