Follow these tips for creating a faux stone look on a wall.
1. Remove existing drywall down to the studs using a crowbar. Using an angle grinder, cut random sections of 1/2-inch backer board which will be the foundation for the stones.
2. Lay the cut backer board to the framing to make sure it fits correctly. Use 1-inch galvanized staples to attach the backer board to the studs in the walls in the desired locations of the rock facade.
3. Take a piece of drywall and lay it in front of the wall. Use a rotary tool to cut around the locations where the backer board is installed. Trace and cut around any electrical outlets. Be sure the electricity is turned off first! Once the sheet of drywall is fully cut out, use it as a stencil to create a second piece of that matches the first. Put aside the second piece. Attach the first layer of drywall to the studs with a screw gun.
4. When the drywall is hung, select the stones you want to use in the backer board holes and check for fit. Apply mortar with adhesive admix to the back of the stones with a trowel. Tip: Moistening the backer board with water will help the mortar on the back of the stones adhere better.
5. Attach furring strips made from 5/8-inch drywall (or 1 to 2-inch wide strips of wood) to the first layer of drywall to increase the depth of the wall. Screw the furring strips into the studs in the wall.
6. Place the second piece of drywall you cut earlier on the top of the furring strips. Screw the drywall into the studs with 1-1/2 inch screws so they go through both layers of drywall. Use drywall tape to begin prepping the wall for mudding and joint compound.
7. Use drywall mud/joint compound to fill the seams. Don't be afraid to scrape the mud onto the stones for a more rugged look. Use taping knives to move and scrape the compound onto other parts of the wall to give the wall texture and an antique look. Paint wall with desired color.