How to Build a Fireplace Mantel Shelf

Plan the design of the shelf to help determine the needed materials. Check to make sure that the wood you are using is sturdy enough to support any items that may rest on the mantel, including larger, heavier pieces, such as a mantel clock.

Assemble the shelf if it is not all one unit. Attach any ornamental pieces, such as crown molding or other decorative additions, to the shelf.

Determine the type of wall backing behind the fireplace by drilling pilot holes with a 1/4-inch bit. The type of wall backing will determine the size and type of brackets or mounts used to secure the mantel shelf. This is not necessary if the fireplace is constructed of masonry or stone.

Level the brackets or mounts with the ceiling and the floor prior to securing them in place. Measure from the floor to the shelf at each end of the shelf. This will ensure that the shelf is parallel to the floor rather than absolutely level, which may make it look crooked compared to the floor if the floor is not level. Use an appropriate-grade adhesive to mount the brackets on a masonry or stone fireplace and grout any joints.

Place the mantel shelf onto the brackets and secure it as necessary. Use 2-inch screws to fasten the shelf bracket to a solid wood backing or studs. Use molly bolts if the wall is hollow behind the fireplace.

Attach protective drop cloths or plastic sheeting to the fireplace below the shelf then sand and stain or paint the mantel shelf.