How to Install a Mantel on Cultured Stones

Examine the surface of the mantel for signs of damage. Sand any rough edges smooth, and use wood putty to fill in any holes in the wood.

Brush a coat of primer or stain onto the mantel. Go with the grain of the wood while applying the primer or stain, taking care to prevent it from beading up along the edges of the mantel. Allow the coat to dry.

Assemble the mantel, following the instructions provided for the one you purchased. When assembling the mantlel, do it with the back side up -- it will be more stable.

Flip the mantel over, and place it against the cultured stones around the fireplace. Have an assistant help you with this if you need it.

Place a level on top of the mantel, using shims underneath to level it out if necessary.

Trace the mantel onto the cultured stones, then carefully remove it and lay it down where it won't be damaged.

Measure the inside surface of the mantel shelf, and cut a 2-by-4 board to match the length. The 2-by-4 will be a "cleat" that holds the mantel to the stones.

Place the cleat inside the shelf of the mantel, and measure the distance between the bottom of the cleat and the bottom inside edge of the legs. Remove the shelf cleat. Cut a 2-by-4 for each leg that matches the distance. These boards will be the leg cleats.

Place the cleats inside the legs. If the cleats are thicker than the legs, cut them thinner until they fit. If the legs are too thin, nail a second 2-by-4 to them.

Hold the shelf cleat against the cultured stones along the bottom of the line you drew for the shelf when you traced the mantel. Drill four evenly-spaced pilot holes through the cleat and into the cultured stones with a hammer drill that has a 1/2-inch carbide-tipped masonry drill bit.

Drill the 2 1/2-inch concrete screws through the holes and into the stones.

Install the cleats for the legs of the mantel, using the same process you used for the shelf cleat.

Move the mantel back into position against the cultured stones. Drill a 2-inch finishing screw through the mantel and into the cleats every 16 inches along the back edge of the shelf and the back edge of the legs. Drive the screws deep enough that they're just below the surface of the mantel. This allows you to cover the screws with wood putty to hide them.

Nail molding to the inner edges of the mantel to cover any gap between the mantel and the cultured stones.

Run a bead of caulk along the joint between the mantel and the cultured stones on the outside edge of the mantel.

Cover the finishing screws. Use wood putty if you're painting the mantel, and plugs if you're using stain. If you're painting the mantel, cover the wood putty with primer, and allow it to dry.

Add a second coat of stain to the mantel, or paint it.