How to Anchor the Corner Post of a Stair Case to the Floor

Stand the corner post on the floor at the foot of the staircase and against the carriage. The carriage is the outside front corner of the staircase opposite the wall.

Make a mark 1 inch from the floor on the sides of the corner post, perpendicular to the stairs. Make marks on the front of the corner post 1 inch and 4 inches from the floor.

Drill holes at a 30 degree angle into the corner post at the marks on the side with a 3/16-inch drill bit. Make another hole at a 30 degree angle at the 1-inch mark on the front of the corner post. Drill the hole at the 4-inch mark straight into the stair case carriage.

Insert a 1/2-inch countersink bit into your drill and drill a 1/4-inch-deep countersink into each hole. This helps to sink the heads of the screws below the surface of the wood.

Drive 3½-inch wood screws into each of the bottom holes, at an angle, with a cordless screwdriver or screwdriver bit in a drill. Drive another wood screw into the hole at the 4-inch mark.

Push the wood plugs into each of the holes over the screw heads. If necessary, sand the plugs with 220-grit sandpaper until they fit flush to the surface of the wood.