How do I stop stairs creaking?

Stairs are a jointed timber assembly rather than boards on joists, so the noise comes from different places than a creaking floor and is fixed differently. The single most useful question is whether you can reach the underside.

Safety

Step by step

1. Find exactly where it creaks.Have someone walk slowly up and down while you listen from below or kneel alongside. Mark the exact tread and note whether the noise comes at the front, the back or one side. Guessing wastes the whole job.
2. Work out which joint is moving.The commonest is where the back of a tread meets the riser behind it. Next is where the front of a tread meets the top of the riser below. Press each area while someone flexes the step to confirm.
3. Check whether you can get underneath.An open understairs cupboard or an unboarded soffit changes everything. Fixes from below are permanent and leave nothing visible, and they are much easier than working from above.
4. Refit or add glue blocks from below.Triangular blocks glued into the internal angle where tread meets riser. Original ones frequently come loose. Clean the surfaces, apply wood glue generously, and rub the block into place until it grabs.
5. Drive wedges into the string joints from below.Where the treads and risers meet the side strings there are usually wedges. Loose ones can be tapped back with glue, or replaced. This is the classic repair and it lasts.
6. Screw the riser to the tread from below.Where blocks and wedges are not enough, short screws through the back of the riser into the underside of the tread pull the joint tight. Drill pilot holes and keep the screws well short of the tread's top surface.
7. Try talc or graphite from above first.Work talcum powder or powdered graphite into the joint line with a brush, then work the step. It lubricates the rubbing surfaces and often silences a minor creak entirely, with no damage and nothing to undo.
8. Use thin wooden shims for a visible gap.A slim shim dipped in glue and tapped into a visible gap at the front of a tread, then cut flush when dry. Effective where the joint has opened slightly.
9. Screw through the tread as a last resort.Pilot-drill and countersink, screw down into the riser below, and fill. It is visible unless carpeted, and it is irreversible — which is why it comes after everything else.
10. Never nail it.Nails work loose again with the flexing that caused the problem, and they split the tread. Screws hold; nails buy a season.
11. Check the balusters and handrail while you are there.A creak from the side is sometimes a loose baluster rather than a tread. A loose handrail or baluster is a safety issue rather than a noise one and should be dealt with.
12. Accept some seasonal movement.Timber moves with humidity, so a stair that creaks only in winter may not be worth chasing. Fix the ones that are consistent and loud.

Tips

• Do the whole staircase in one session if you are working from below. Finding the access again for one more tread is the annoying part.
• Carpeting a staircase muffles creaks considerably and is a legitimate answer if the noise is the only problem.
• If a tread flexes noticeably under weight rather than just creaking, stop and have it looked at. That is different from a noise.

Common mistakes

• Nailing a creaking tread down — Nails loosen again under the same flexing that caused the creak, and they split the timber. Screws with pilot holes hold; nails do not.
• Screwing through a tread without checking underneath — Cables and pipes are frequently run in the understairs void. Check what is below before driving anything through.

If it doesn't work

Questions people ask