How do I stop a floor squeaking without taking the carpet up?

The squeak is a board moving against its fixing, and the cure is a screw into the joist — that part is the same as on a bare floor. The only difficulty is doing it through a carpet without cutting it, and that turns out to be easier than most people expect, because carpet pile closes over a countersunk head completely.

Safety

What you'll need

• a cable and pipe detector
• a bradawl
• fine countersunk screws, long enough to reach the joist
• a drill/driver with a clutch
• a helper to stand on the squeak (optional)

Step by step

1. Map the squeak precisely.Have someone rock on it while you listen from directly above and, if you can, from the room below. Mark the exact spot with a pin or a scrap of tape.
2. Find the joist.Run a detector across the carpet at right angles to the board direction. Joists are usually at about 400mm centres, so once you have found one the rest follow a rhythm. Mark two points on each joist so you can draw its line.
3. Scan for cables and pipes on that line.Do this at every intended fixing point, not once for the room. This is the step that keeps the job safe.
4. Part the pile rather than cutting it.Push a bradawl through the pile at the fixing point, working the fibres apart rather than through them. A cut loop unravels; a parted one closes back.
5. Drive a fine screw through everything into the joist.Use a screw with a small head and a fine shank. Set the driver clutch low and drive slowly, so the screw pulls the board down rather than spinning and winding carpet fibres around itself.
6. Stop as soon as the head reaches the backing.You want the head just below the carpet backing, pulling the board down. Driving further pulls the carpet down into a visible dimple.
7. Test and repeat.Stand on it. If it still moves, add a second screw about 100mm along the joist, and one on the neighbouring joist. Most squeaks need two or three.
8. Brush the pile back over.A stiff brush or a fingernail lifts the surrounding fibres over the head. On a cut pile carpet the fixing becomes invisible; on a loop pile it is faint but visible on close inspection.

Alternatives

• Proprietary squeak kits: Kits that use a scored screw driven through the carpet, then snapped off below the surface with a special jig. They work well on cut-pile carpet over timber and are designed for exactly this job.
• Fix from below: Where there is a cellar, a crawl space or an accessible ceiling void, a glued wedge driven between joist and board, or a small block screwed to the joist side under the board, cures the squeak with nothing visible above at all. This is the best method when it is available.
• Lift the carpet edge: Carpet on gripper rods can be pulled off the grippers along one wall and folded back, the floor fixed properly, and the carpet re-stretched onto the grippers. It is more work but it is the right answer if the squeaking is widespread.
• Talc or graphite: For boards squeaking against each other rather than against a fixing, powder worked into the joint lubricates the contact. It cannot be done through carpet, and it is a temporary measure, but it costs nothing.

Questions people ask