I’ve always been intrigued by the idea of creating a “carpet” of stone on a deck, much like you’d see inside someone’s home, defining a space. We first experimented with a flagstone inlay, mortared down in much the same way a floor is laid: 3/4-inch plywood over strong joist work, then mesh reinforcement and mortar. We drilled holes through the mortar joints to allow water to escape, because we did not pitch the deck.
Now we often use materials like travertine that have a more uniform thickness, and instead of plywood for an underlayment, we install a heavy-duty 11/2-inch-thick fiberglass grating. Then we basically dry-lay the stone on it so we have good drainage through the deck. We’ve also used construction adhesive to mount stone to steps and to do picture-framing inlays in decks. Clients love the one-of-a-kind detail and I enjoy combining the stone with the wood.
Bruce Zaretsky owns Zaretsky and Associates in Macedon, N.Y.