How to repair floorboards
You may need to lift a floorboard in order to access pipes or cables beneath the floor for repairs.
What you'll need to fix your floorboards:
- Thin-bladed knife
- Drill and twist drill bits
- Bolster chisel
- Also for tongue-and-groove boards
- Circular saw (or panel saw or flooring saw)
- 50 or 75mm floorboard nails
- 75mm No 8 screws
- Pieces of timber about 40mm square and 100mm longer than the width of the boards
Before you start
First find out whether the boards are tongue-and-groove or square edge by poking a thin-bladed knife between them. If they're square edge, the blade will pass right through.
Removing a square-edge board
Before lifting the board, you must cut across it at each end just before it meets a joist. Lines of nails indicate joist centres.
1. Drill a 10mm starting hole near the edge of the board you want to remove and complete the cut across it with a jigsaw.
2. Starting at one end, prise out fixing nails by levering up the board with a bolster chisel.
3. Once you've loosened 1 or 2 sets of nails, push the handle of a hammer under the board as far from the loose end as possible, and try to prise the board up. This sends a shock wave along the whole length, loosening nails farther along, which you can then remove.
4. Push the hammer farther forward and repeat the process until the board is free.
How to remove tongues
On tongue-and-groove boards, the tongues on each side of the board must be removed. If adjoining boards are to be lifted, only the tongues at the outer edges of the group need cutting.
1. Adjust the depth of cut on a circular saw so that the blade just protrudes below the underside of the tongue. Since floorboards are usually 19mm thick, the underside of the tongue will be about 13mm below the surface.
This will avoid pipes and cables. If you don't have a circular saw, use a panel or flooring saw. Cut at a shallow angle.
2. Place the blade between the boards, switch on the power and move the saw along the length of board.
3. With the tongues removed you should be able to see the joists between the boards. Remove the board in the same way as a square-edge board.
Replacing the board
Use new nails and proper floorboard brads. You'll not be able to nail the board to a joist at its ends as it's been sawn off before the joists.
1. Screw a short batten to the side of each joist, its top edge jammed hard up against the underside of adjacent floorboards still in position. Nail the board to the batten.
Curing loose and squeaking boards
A floorboard squeaks because it is not firmly held to its joist. When someone steps on it, it springs under the weight, rubbing against a neighbouring board. A squeak can be temporarily cured by dusting talc down the side of the board.
Not all loose boards squeak—there may be too big a gap around them—but even so they should be properly secured before a floor covering is laid, otherwise you will feel (and hear) the movement under new flooring.
A board becomes loose when one or more of its fixing nails loses its grip due to vibration or the movement of the joist below. Prise out the nail if it's still there and refix the board with a screw big enough to fill the hole left by the nail. A 50mm No 8 screw should be suitable.
The screw will hold the board securely in place, and as it goes exactly into the same hole as the nail there should be no danger of striking a cable or pipe.