4 tips for fixing squeaky stairs

Stairs squeak when you step on one piece of wood and it rubs against another. Here are four tips to find and stop the loud squeaking noises. 

• Isolate the problem by walking up and down the stairs to see which step is squeaking. Try to tell if the squeak is coming from the back, the front or the side of the step.
• Better yet, if you can get underneath the stairway, have someone walk on the steps so you can pinpoint and mark the squeaky spots from below.

• One easy, long-lasting way to quiet a squeak is to apply a thin bead of caulk under the step nosing, so that it cushions the joint where the tread meets the riser.
• After applying the caulk, run a plastic spoon along it to shape it, remove the excess, and push some caulk into the squeaky joint. Clean up any stray caulk before it dries. If you can get to the steps from the underside, caulk the seams of the squeaky step from there, too.
• Another simple way to eliminate a squeak is to add some reinforcement on the stairs' underside. Screw one leg of an L-bracket to the riser, leaving a small gap between the other leg and the tread. Run a bead of glue between the tread and riser, and then screw the bracket to the tread, pulling it down slightly in the process. Make sure the screws are at least half a centimetre (1/4 inch) shorter than the tread's thickness so that the screw tip doesn't come out the other side.

• Over the years, newel posts — the large posts at the top and bottom of a stair's railing — get a lot of stress and strain and can start to wobble. How you fix it depends on how its base is attached.
• In newer homes, most newel posts are secured to the stair's framework with lag screws. The lag screws are hidden by wooden plugs that are difficult to get out. Drive in extra lag screws instead. Drill a pilot hole for each screw along with a deep countersink hole for the head. Fill the hole with a wood plug or wood putty.
• If the newel post goes through the floor and is attached to a joist that you can access in the basement, try driving a few extra nails through the post and into the joist. If this doesn't work, nail pieces of wood to the joist, as braces that press solidly against the post on each side.
• If the wobbly post is attached to the floor by a metal plate, the screws have come loose in their holes. Back out the old screws, and drive in new, larger diameter screws.
• In an older home, some newel posts are anchored by a threaded rod that runs the entire length of the post. To tighten the post, just tighten the rod from below.

• Use shims to fill small gaps between treads, risers and stringers so that loose boards can't rub against each other and squeak. Dab a little construction glue on a shim and drive it into a joint gap with a hammer. (Buy ready-made shims at a home centre.)
• It's best to do this on the underside of the stairs. If this isn't possible and you want to shim a gap between riser and tread from above, make the repair less noticeable by using a utility knife to trim the shim flush with the riser.