DIY: Install a Wood Mantel to a Brick Fireplace

Assemble the wood mantel kit before installing it. Available in a variety of styles and sizes, the mantel is basically comprised of a shelf and two legs that are vertically attached to each end along its lower side. Lay the mantel face-down on the floor. Push each leg into the corner of the shelf, ensuring that the factory-machined dowels fit into the pre-drilled holes so the leg seams are flush and tight.

Ask an assistant to hold one end of the mantel while you hold the other and center it over the fireplace, flush against the wall. Leave at least 6 inches of clearance space between the opening for the fireplace and the mantel to prevent a fire hazard. Place a carpenter's level across the top of the mantel and check that it is even and centered over the fireplace. Tap the legs against the walls, if necessary, until the mantel is plumb.

Trace the upper edge of the mantel on the wall with a pencil to form a guide line to help you position the 2-by-4 lumber supports or cleats.

Remove the mantel and place it face-down on the floor. Measure the shelf’s inner width to calculate the horizontal cleat’s length then cut a length of 2-by-4 lumber to this measurement. Dry-fit this top cleat in place. Also measure the width and length for the vertical or leg cleats then repeat the process of cutting lengths of lumber to the measurements and dry-fitting them inside the legs.

Measure the thickness of the mantel’s edges that will sit flush against the wall. Mark this measurement along the pencil tracing on the wall then join the dots, forming a line that determines the location for the cleats.

Hold the upper cleat against the wall and drill four 1/2-inch holes through it with a masonry bit. Then use a screwdriver bit and drill 2 1/2-inch concrete screws into the pilot holes. Repeat the process for securing the vertical leg cleats.

Fit the mantel over the cleats, aligning it with the pencil outline on the wall. Insert 2-inch screws every 18 inches along the shelf’s back above the upper cleat. Repeat the process of securing the outer edges of the legs to the vertical cleats.