Can I just screw the loose step down?

It is the most common repair and the one that fails. Screwing through the tread into the thin riser below tends to split it, and because the wedges are still loose the tread keeps working against the fixing. The joint is repaired from underneath with wedges and glue blocks wherever that access exists.

Several of my stairs have gone loose at once — why?

Usually the whole flight drying and shrinking, most often after years of central heating. The wedges lose their grip together rather than one at a time. Re-wedging the flight as one job is quicker and lasts longer than chasing individual steps.

Is a cracked nosing safe to use?

No. The nosing is the part your heel and the ball of your foot load on the way down, and a split there can break away under weight. Stop using that step and have the tread spliced or replaced.

Does a repaired step have to meet current regulations?

Repairing an existing tread is not rebuilding the stair, so an older flight is not forced to current geometry. What matters is that the repair restores the original rise and going — Approved Document K expects rise and going to stay consistent through a flight, and a tread reset low or high creates two irregular steps.

High risk

Updated 30 August 2026

Loose Or Cracked Stair Tread

A step moves, tilts or drops slightly when you stand on it, or the front edge has split away.

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What's happening?

A tread is not simply nailed on top of the stair. In a traditional cut-string staircase each tread sits in a housing in the side strings and is locked there by hardwood wedges driven in behind it, with glue blocks in the internal angle between tread and riser. That assembly is what makes a flight rigid. When a tread moves independently of the flight, the wedges have shrunk and worked loose, the glue blocks have dropped off, or the riser behind it has parted from the underside. A split along the nosing is different again — that is the front lip failing in bending, usually where the tread has been undercut for a carpet gripper or where a knot runs across it. Either way the step has stopped being fixed, and a step that moves under load is a fall waiting to happen.

What usually causes it?

Hardwood wedges under the tread shrunk and worked loose, so the tread lifts in its housing
Glue blocks in the angle between tread and riser dropped away, removing the joint's stiffness
Riser separated from the underside of the tread, letting the tread flex and drop at the front
Nosing split where it was undercut too deeply for a carpet gripper rod or stair rod
Tread cut from timber with a knot or short grain running across the nosing
Screws or nails driven through the tread face into the riser, which splits the riser and loosens over time
A previous repair that packed the gap rather than re-wedging, so nothing is actually gripping

Is it dangerous?

Yes — this is the one carpentry fault on a staircase that is genuinely high risk. A tread that tilts or drops even a few millimetres under weight breaks the rhythm a person's feet expect, and stairs are among the most common places for serious falls at home. Approved Document K sets the geometry a private stair should keep: rise between 150mm and 220mm, going between 220mm and 300mm, a maximum pitch of 42 degrees, and consistent rise and going through the flight. A loose tread that sits low changes the rise on two steps at once. A cracked nosing can give way completely under a heel. Treat a moving tread as a step not to use until it is fixed.

Can I fix it myself?

Only if you can get underneath. Where the stair soffit is open — a cellar flight, or one with the plasterboard removed — re-gluing and driving new wedges and glue blocks from below is a proper repair and well within a competent DIY reach. Where the underside is plastered and closed, everything has to be done from above, and that is where amateur repairs go wrong: screwing down through the tread face into the riser splits the riser, squeaks within a year and leaves visible plugs. Never fill a gap under a loose tread with sealant or packers. Stop using the step until it is repaired properly, and do not remove the handrail while working on it.

When should you call a carpenter?

Call a carpenter as a priority if a tread moves, tilts or drops under weight, if a nosing has split, or if the underside is closed in so the repair has to be done blind. Also call if the flight is a feature staircase, if the strings themselves have split, or if more than one tread is loose — that usually means the whole flight has dried and shrunk rather than one step failing, and it wants wedging through as a single job.

What will the carpenter actually do?

Load-test each tread and check the strings, risers and newels to find whether one step or the whole flight has moved
Open the soffit where necessary to reach the underside rather than face-fixing from above
Cut and drive new hardwood wedges into the tread and riser housings, and re-glue them
Replace missing glue blocks in the tread-to-riser angle to restore the flight's stiffness
Splice a new nosing or replace the tread where the front edge has split through
Re-check rise and going across the flight after the repair so the step heights stay consistent

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Creaking Or Squeaky StairsLow risk Loose Banister Or Wobbly SpindlesHigh risk Woodworm Holes In TimberCaution

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