Granite shelves are beautiful additions to a room, but they require careful installation due to their weight. The key is to use strong brackets and install them on backer board, a sheet surface like drywall but denser and designed to hold weight. It is important to install the shelf properly, or the weight of the granite can pull down the wall surface, causing a dangerous and ugly situation. If your granite shelf is large, you'll need a second person to help install it.
Things You'll Need
- Measuring tape
- Ruler or straightedge
- Stud finder
- 2 sheets of backer board
- Long drywall screws
- Water-based paint
- Steel brackets
- Ratchet wrench
- Tack cloth
- Dish soap (optional)
- Polyurethane adhesive
Measure how high you want the shelf to hang. Draw a line the length of the shelf using a pencil, a straightedge and a level.
Check for studs along the line using a stud finder. Mark the stud locations with a pencil.
Install a piece of backer board along the edges. Use backer board that is 1/2 inch deep, 4 inches wide and as long as the shelf. Have someone hold the board so the top of the board is flush with the pencil line. Drill pilot holes through the backer board into the stud. Screw the backer board in place with long drywall screws. Check that the board is level.
Install a second, larger piece of backer board below the first one. Choose a board that is 1/2 inch deep, as long as the shelf and wide enough to support the brackets. Screw the board into position as you did with the original board.
Paint the backer board with water-based paint so it matches your home decor. Allow the paint to cure before proceeding.
Line the brackets up so they are flush with the top board and each one is over a stud. Drill pilot holes for each screw hole in the bracket before installing the bracket. Check that the brackets are level before making your pilot holes.
Install the first bracket using bolts that fit into the holes in the bracket. Tighten it with a ratchet wrench. Set a level on top of the bracket to make sure it stays level as you are working. Continue to install the remaining brackets in the same manner. Make sure each bracket is level.
Lay the granite on the brackets and line it up on either side. Use a level to make sure it is still even. Remove the granite shelf.
Wipe the shelves with a cloth to remove any dust so the adhesive can stick better. If the shelves are greasy, clean them with dish soap and water, and dry them thoroughly.
Apply a line of polyurethane adhesive that is designed for use on granite along the middle of each bracket.
Set the shelf on top of the brackets so it is perfectly aligned in the location you desire. The weight of the granite will push onto the brackets and hold it in place as it cures. Allow the adhesive to cure according to the package instructions before using the shelf.
Tips & Warnings
- Drill all holes no more than 18 inches apart to ensure that the shelf has enough support.
- Use brackets that are wide enough for the shelf. The granite shelf should have no more than a 4-inch lip over the brackets.