Dry Deck Over Living Space, Images 11-20

The author installs galvanized expanded lath on the deck, lapping it onto the flashings and fastening it down with closely spaced staples.

Polymer cement is troweled over the lath.

Once the cement has set, the crew uses mason’s stones to grind off any high spots and lap marks in the finish.

When the first layer of cement has cured, it is covered with overlapping sheets of fiberglass matting.

The cement is coated with acrylic resin. The resin soaks through and bonds the mat to the substrate, then cures to form a continuous waterproof membrane. It's important to lap the resin onto the vertical leg of the wall flashing.

Long exposure to sunlight will damage the acrylic resin membrane, so it is protected under a thin layer of the same polymer cement that was used to cover the lath.

After the second layer of polymer cement cures, the deck can be finished — in this case with a spray-applied texture.

The texture is troweled flat shortly after application to leave a knockdown finish.

The texture is coated with pigmented concrete sealer, which dries to form a tough walkable surface. Because this deck was finished before the exterior trim was complete, it will require protection while the building paper and siding are installed.

More typically, the texture and sealer are applied at the very end of the project.

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