How to Build a Floating Shelf Support
A floating shelf has no visible hardware. It appears as though it is floating against the wall. This system achieves very clean lines in any room of your home. Used to hold anything from knick-knacks to books, the floating shelf is both decorative and practical. While the installation is not nearly as simple as pre-packaged, adjustable shelves, the results are much nicer. This is without a doubt a "measure twice, cut once" job.
Step 1 - Lay out Shelves
Determine general placement of the floating shelf. Using a stud finder, locate and mark studs. Mark each stud in at least 2 spots to establish a vertical placement of shelves. If there are multiple shelves, they will be placed along the same studs. Marking a vertical line on each stud eliminates the need to repeat the process for each shelf. Mark as many studs as necessary, to accommodate the shelf length. With the level, establish a perfectly straight line along each stud, marking each with masking tape. Using the level, mark the elevation of the top of each shelf. Mark the horizontal position of each shelf with masking tape (horizontal lines).
Step 2 - Make Cleats (Supports)
A floating shelf is an open-ended box. Measure the pocket inside the shelf to determine the exact size lumber needed for the cleat. Choose a piece of lumber that will fit inside the pocket, so the wider edge of the cleat will attach to the wall. Mark the lumber about 1/8 to 1/4-inch less than measured length. If the cleat is too long, the shelf will not fit over it. The shelf should be snug over the support. Repeat for each shelf. Do not assume that every shelf is exactly the same. Even 1/16-inch variance will prevent the shelf from fitting over the cleat.
Step 3 - Cleat Preparation
With help, hold the cleat up to the marks on the wall, hold the level and mark where the studs fall on the cleat. At each point marked, drill through the cleat down the center of the wide side of lumber chosen in Step 2. The bolt size will determine the drill bit size.
Step 4 - Attach Cleat to Wall
Using a bit 1 size smaller than the lag bolt size, drill pilot holes in studs at points marked in Step 1. With help, hold the cleat level, so the top of the cleat is even with the shelf line. Pushing the lag bolt through the cleat at 1 end, and finding the first pilot hole, use the socket wrench to partially attach the cleat to the wall. The bolts must be at least 2-inches longer than the width of cleat (for example, the width of a 2x4 piece of lumber is 1 1/2 inches, so the bolts will be minimum of 3 1/2 inches long). Repeat at the other end. Go back to the end where you started, and repeat for the second bolt. Continue back and forth in this manner, until all bolts are started. Check for level. If the shelf is level, tighten bolts in same pattern as initial installation. Repeat for remaining shelves. Be sure to install bolts in a back and forth pattern, to distribute load evenly across the floating shelf.