Mark the location of the proposed post with chalk. Measure the exact location of the post with a tape measure because you will only have one chance to set it in the right spot. Mark the locations of the drill holes for a wrought-iron post base or the locations of the holes in the post base for a wood post.
Drill holes in the concrete, using a hammer drill or a power drill with masonry bit. Use a bit approximately three times the diameter of the bolts that will hold the post to the concrete sidewalk. For example, a 1/4-inch bolt will require a hole in the cement 3/4 inch in diameter. Drill each hole about 3 inches deep.
Insert the masonry inserts, sometimes call lag shields, into the hole. These inserts are sold with the masonry lag bolts or screws.
Place the wrought-iron post base or the wood post base over the holes with the inserts in place. Align the holes of the bases with the inserts.
Insert the screw or lag bolt, with a lock washer in place, into the insert. Use a screwdriver or wrench to tighten the screw of lag bolt into the insert. The insertion of the screw or bolt causes the masonry insert to expand and create a tight grip against the concrete.
Install the wood fence post in the post base. This commonly involves wood screws or lag bolts running through portions of the base that run up the side of the post.