Squeaking Floorboards And Stairs

A squeak is friction between two components moving relative to each other. Silencing it permanently means identifying which pair is moving rather than treating the noise where it is heard.

Where the movement actually is

Timber floors are boards fixed across joists. A squeak arises when a board lifts and drops against a joist, when a fixing moves in its hole, or when two board edges rub.

Nails are the usual culprit in older floors. A nail shank works loose in the joist over decades, so the board rides up and down the shank each time it is stepped on.

Having someone else walk the floor while you listen from directly beneath, or with your hand on the board, locates the moving pair far more reliably than guessing.

Why timber loosens in the first place

Wood expands and contracts across the grain with the moisture in the air, and heating systems drive indoor humidity through a wide annual swing.

Each cycle slightly enlarges the hole around a smooth nail shank. Screws resist this because their threads hold along the length of the shank rather than by friction alone.

Joists themselves dry and shrink after installation, which opens small gaps between joist and board that only appear years after the floor was laid.

Fixing from below where you can

If the underside is accessible, a shim of thin timber coated in adhesive and eased into the gap between joist and board removes the movement without touching the finished floor.

Do not drive the shim hard. Forcing it lifts the board and creates a hump, and often transfers the squeak to the next board along.

Blocking between joists reduces deflection over a wider area, which helps where a whole section of floor moves rather than a single board.

Fixing from above

From the top, the answer is usually to replace the loose nail with a screw driven into the centre of the joist, countersunk below the surface.

Pilot drilling prevents splitting near board ends, and locating the joist accurately matters because a screw into the void does nothing at all.

Under a fitted carpet the screw heads are invisible, which makes this the low-effort route in bedrooms and the wrong one on an exposed board floor.

Stairs are a different geometry

A staircase is a set of treads and risers held in housings cut into the strings, and the squeak usually comes from a tread flexing against the riser behind it.

Traditional staircases carry glue blocks in the internal angles. These fall off with age, and refitting them from underneath restores the original stiffness.

Where the underside is boxed in, wedges driven into the housings from the front and trimmed flush achieve a similar result, though the repair is visible on an uncarpeted stair.