Step 1: Demolish the Fireplace

Begin by removing the existing mantel and materials from the wall. Use whatever tools work best for the material that needs removing. Often, a crowbar, hammer and chisel work well to remove most building materials. Make sure that the resulting drywall base is sound and level. If not, patch or repair it so that it is.

Step 2: Install Tar Paper

Apply a layer of heavy-grade tar paper to the drywall base. The tar paper will serve as a moisture barrier. Stretch the paper tight across the drywall and use a hammer stapler to secure it in place.

Step 3: Install Metal Lath

Use a stud finder to locate and mark the studs. Secure the expanded metal lath to the wall studs at the edges and in the middle using masonry screws. Leave at least a 2"overlap where lath pieces meet. Use wire snips to cut the lath pieces to the appropriate sizes

Tip: When installing the metal lath, it is imperative that it is hung in the proper direction. The lath should be rough when running your fingers down and smooth when going up. This ensures maximum support.

Step 4: Apply Scratch Coat

Prepare the mortar mix according to the manufacturer’s instructions. Let the mix sit for five minutes before using it to make sure that it is properly set. Use a hawk and trowel to apply the mortar onto the lath. Press the mortar into the lath using upward strokes. Cover the lath entirely with mortar. Before it dries, scratch the surface using a trowel to create a rough surface.

Tip: Before applying the scratch coat, cover the fireplace with newspaper to prevent it from being damaged by the mortar.

Step 5: Install Mantel

Once the scratch coat has dried, install the mantel. Locate the center point of the wall and mark it. Mark the desired placement of the mantel with a tape measure and level. Mark and install the mantel anchors. Slide the mantel on top of the anchors, check for level and secure.

Step 6: Set Stone

Begin by separating the flat stones from the corner stones. Start at the corners and work in. Apply a half-inch-thick layer of prepared mortar mix to the back of a stone and firmly hold it in place for 30 seconds to secure. After all of the stone is set, use a jointer to fill the joints with mortar to cover the lath.

Tip: When setting stone, make sure to alternate, or tooth, the joints to prevent continuous joints.