How to Secure Wood to a CMU

Drill 1/8-inch holes along the wood that will be attached to the CMU. Space the holes evenly along the wood and in the center of the material. For example, space the holes 24 inches apart along an 8-foot 2-by-4 and directly in the center of the board's width. If necessary, place the holes closer along wood that will require greater holding strength and farther apart for wood that will not require much holding strength, but do not go greater than 32 inches along the wood.

Place the wood in place along the CMU or CMU structure. Plumb and level the wood with a 4-foot level. Place a pencil mark along the edge of the wood as a reference. Have a helper hold the wood in place. Drill through the predrilled hole and into the concrete block using a hammer drill and a 3/16-inch concrete drill bit. Mark the wood's location on the wall for reference. For example, place a T at the top of the wood for top and a B at the bottom. Additionally, place an R for right and an L for left.

Remove the wood from the CMU or CMU structure. Redrill the holes to clean out wood that may have splintered during your hammer-drilling process. Replace the wood on the CMU with the correct marks in place -- L, R, T and B -- and align the wood with the previously placed reference alignment line. Insert 1/4-inch Tapcon screws through each hole in the wood and through the CMU until the screw in tight, but do not over tighten.