How to Finish Basement Jack Posts

Cut two two-by-six studs to fit between the floor and the top of the post. Use treated lumber or cut a bottom plate out of treated lumber whenever contacting a concrete floor with framing members. Cut the studs a little long so that friction will help you hold them in place while attaching the L-brackets.

Apply construction adhesive liberally with a caulking gun to the side of the post. The adhesive helps to hold the stud firmly against the post and keeps the stud from bowing out and cracking the drywall.

Wedge the two-by-six in place and align it with the beam above. Use your level to set it plumb.

Attach the top of the two-by-six to the framing above with 8d framing nails or 2 1/2-inch drywall screws. If using screws, drill a pilot hole to keep the lumber from splitting.

Slide an L-bracket up to the bottom of the post and attach it with 1 1/4-inch drywall screws. If your brackets are narrow, install a bracket about 3/4 inch from each side.

Drill through the brackets into the concrete with a rotary hammer drill and a 1/4-inch masonry bit, then drive in the concrete anchors. Verify that the framing is set exactly vertical or plumb.

Install the other two-by-six on the opposite side of the jack post as described in Steps 2 through 6.

Install 1/2-inch drywall around the post. Run a corner bead with the caulking gun, finishing with joint compound, and sand smooth.