What do I do about a stair tread that moves?
A moving tread is different from a creaking one. Creaks are noise; movement is a failed joint, and it needs fixing rather than silencing.
- Difficulty
- intermediate
- Time
- 1 hr
- Read
- 2 min
- Safety
- warning
Short answer
Work out whether the tread is loose at the front, at the back, or at its ends in the strings. Wedges and glue blocks under the stair are the traditional fixings and are usually what has failed. Access from below is far better than screwing through the tread from above.
A traditional staircase is a set of treads and risers housed into two strings and held tight by glued wedges, with blocks in the internal angles. Almost all movement traces to those wedges and blocks drying out, shrinking and dropping out. That is why the repair is nearly always underneath rather than on top.
Safety
Step by step
- Establish whether it is movement or just noise.Stand on the tread and feel for deflection at the front edge, then at each end. Noise without movement is a creak, and GuideHQ has a guide for that. Visible or felt movement is this guide.
- Look underneath if you can.Under a stair that is open beneath — a cupboard, or an unlined understairs space — you can see the wedges and glue blocks. That is where the repair happens and it is a far better fix than anything done from above.
- Check for missing or loose wedges.The wedges driven into the housings in each string are what pull the tread tight. Dry, loose or absent wedges are the commonest cause. They can be knocked out, cleaned up and replaced with new ones, glued.
- Replace the glue blocks in the angle.Small triangular blocks glued into the internal corner between tread and riser stop the joint hinging. They dry out and fall off over decades. New blocks, glued and rubbed into place, restore a great deal of rigidity.
- Screw the riser into the back of the tread from below.Where the tread and riser have separated, screwing through the riser into the tread from underneath closes the joint without any fixing showing on the stair.
- Only fix from above as a last resort.Screwing down through the tread works but is visible, and on an open staircase it looks poor. Countersink, plug and finish if you must, and pilot the holes so the tread does not split.
- Do not rely on adhesive alone into a moving joint.A joint that has been working for years is worn and often dirty. Clean it out and use a mechanical fixing as well as glue.
- Deal with a cracked or split tread as a replacement.A tread with a split running along it is not a repair candidate. That is a structural component and it should be replaced properly.
Questions people ask
Is a moving tread dangerous?
Yes, more so than most household faults, because a stumble on a staircase does far more damage than the same stumble on a floor. It should be dealt with promptly rather than added to a list.
My stairs are boxed in underneath — can I still fix it?
Access is the difficulty. Sometimes a small opening can be made in an understairs cupboard. Otherwise the repair has to come from above, which is more visible and less effective.