How to fix a squeaky staircase
Michel Roy explains how to silence two types of staircases
To avoid working from underneath applied treads, refasten the treads through their surfaces with mechanical fasteners. Regular nails won’t grip enough to prevent squeaking in the future, so predrill and use a ring-shanked nail or a spiral finish nail, as shown.
For a more involved but much longer-lasting fix, countersink wood screws into the treads and cover them with flush-trimmed wooden plugs. With access underneath the staircase, you can also beef them up with glued and screwed blocking, as above.
Tip: In either case, a cracked or broken tread or riser needs to be glued back together, or replaced if it’s severely damaged. If you aren’t able to glue it in place, remove the damaged component first. Strengthen the fix by gluing and screwing a support batten to the back of the piece before reinstalling it.