How to Frame Openings in Concrete Blocks

Measure the opening in the block that must be framed. Take the height and width of the opening and record the measurements on a writing pad. Keep the measurements separate in the case that you have more than one opening.

Cut the 2x8 lumber to fit in the opening. Install the lumber in the opening temporarily, and drill through the lumber and into the concrete blocks with 1/4-inch concrete drill bit and hammer drill. Space the holes 16 inches apart and along the center of the wood.

Drill counter sink holes through the predrilled holes. Place a 1/2-inch drill bit onto the hammer drill, and drill 1/4 inch deep into the top of the 1/4-inch drilled holes. These shallow holes will provide a slot for which to seat the concrete screw heads below the woods surface.

Place the overhead lumber into the opening first and insert the 3/16-inch concrete screws. Sink the screws below the surface of the wood and into the counter bore hole. Place the side 2x8s into the opening and attach them with one concrete screw at the top.

Plumb the lumber with a 4-foot level. Insert the remaining concrete screws into the lumber, sinking the screws into the counter bores below the surface. Check the opening to ensure that the framing is square. Measure the opening at the bottom and top to ensure the same width. Place a framing square into the corner of the opening and check for square.

Loosen the concrete anchor screws and insert wooden shims between the lumber and concrete blocks and retighten the screws.