How to repair floorboards
Introduction
As time goes on; your floorboards might start needing a bit of care and attention. If they've dried out or worked loose from their fittings, they could have started to creak. And if they've split, warped, shrunk or broken, you may need to replace them completely.
Alternatively, you could have to lift some boards to reach cables or pipes that run underneath. How you do this depends on whether your floor is made of tongue-and-groove boards (which are slotted together before being nailed to the joists) or square-edged boards (which are simply butted together).
Whether you want to repair or replace your boards, here are some helpful hints on how to do so. It's also worth remembering that floor coverings can hide a multitude of sins. So if you've taken up your carpet to sand and seal your wooden floor, check for loose boards before you start the job.
Filling holes and cracks in a wooden floor
How to fix creaking floorboards
The reason floorboards become creaky is because their fixing nails get loose and the board isn't firmly attached any more. There are two ways to fix them depending on their condition.
If the floorboard is in good condition, you can take out the nails and screw it down using the existing nail holes. If it's badly damaged at the sides and corners, you'll need to make new holes for the screws. But before you start drilling, do make sure you lift the board and check for pipes and cables.
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Step 1
You'll need to find which part of the floorboard is loose by walking over it and seeing where it moves. If the board is damaged and you can't re-nail in the old holes, you'll have to take the nails out with pincers and then lift the board to check for cables and pipes. Mark any you find on the board in pencil to show where they should go.
Step 2
Next, drill a clearance hole as near to the edge as you can in a part of the board that's not damaged. Then put a screw in the hole and screw it down tightly, checking that it sits below the surface.
Step 3
If you can see the screw head above the surface, take it out, countersink the hole (so the head doesn't stick out) and screw the board down again.
Step 4
Still notice some squeaks after fixing the boards down again? Try sprinkling talcum powder along the joint and work it in with a knife. After a while, the annoying sound should stop.
How to treat timber
Woodworm and dry rot can do lots of harm to structural timbers like joists and roof timbers. You can treat woodworm with a chemical insecticide, but it's better to call in a specialist contractor if you've got a big infestation or dry rot - which is much more serious.
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Top tip - Spotting infestation
Woodworm holes are about 2mm in diameter. If they're dark in colour, there's a chance they've been treated before. Pale dust around the edge of a hole is a tell-tale sign of recent activity and you should treat this straight away. You can tell if wood is infested with dry rot because it becomes dry and spongy, with the fibres breaking down. It can do some serious damage and we'd recommend getting it treated by a professional.
Step 1
Grab a pair of gloves and start by lifting the floorboards. Pour some timber treatment into a pot and brush it onto the timber you want to treat - sticking to the manufacturer's instructions.
Step 2
Brush the underside of any floorboards that show signs of woodworm.
Step 3
Turn the boards over and brush the top side with more of the timber treatment.
How to lift squared-edged boards
Because square-edged boards fit together, they're easy to lift. You'll either need to remove the whole board under the skirting and saw through it near the centre, or just remove the skirting board.
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Step 1
First, check for any under-floor pipes or cables. Then put a wide-bladed bolster chisel into the joint between the boards, close to one end. This will stop you damaging the other boards.
Step 2
Next, push the handle of the bolster chisel down and prise the board up. You'll need to do the same on the other side until you can lift the end of the board high enough to put a cold chisel or wooden wedge under it. This will hold it away from the joist.
Step 3
Gently raise the board by using the claw of your hammer, first on one side of the board and then the other. You can protect nearby boards by putting a thin scrap of wood under the hammer head. Gradually work your way along the board.
Step 4
You can then start pulling most of the nails from the joists. Once you've done that, you should be able to raise the free end of the board and lift up the remainder.
Video
How to replace a section of floorboard
If only a small area of your floorboard is damaged or if the board runs under the skirting, you'll probably find it easier to cut out and replace a section rather than the whole board.
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Safety first
As soon as you lift a board, drive any projecting nails back through the wood, then prise them out with a claw hammer. This way you can't step on them. You should also remove any nails left in the joists.
Step 1
Prise the damaged board up just enough to be able to slide a length of wood underneath it. Then mark cutting lines with a try square and pencil, making sure they run along the centre-line of the joists below.
Step 2
Use a tenon saw to cut the section out (remember to make certain your cuts are square, and not to damage nearby boards). Next, you'll need to measure up for the replacement board. If the existing boards aren't a standard size, you might have to cut down a larger board. You could cut the underside of a thicker board to fit over the joists.
Step 3
Put the new board into position and secure it with 50mm of cut floor brads or ring-shanked nails, taking care to avoid existing holes in the joists. Then drill pilot holes for the nails, which stop any splitting. You could use 50mm countersunk screws (4mm or 5mm gauge) instead.
How to lift tongue-and-groove floorboards
If you need to remove a tongue-and-groove board you'll have to cut through the tongue. And if you're planning to replace it, you'll need a square-edged board.
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Top tip - Finding under-floor pipes and cables
If you're lucky, you'll find any pipes and cable runs already marked on the floorboards. If not, go over the area of floor you want to work on with an electronic pipe and cable detector. Look for signs that the boards have been lifted before (such as damaged edges or lots of fixing holes). Mark the locations of any pipes or cables you find directly on the boards. Or if you're intending to leave the boards exposed, draw up a paper plan and keep it somewhere safe.
Safety first
Keep your pets well out of the way whenever you lift floorboards. And before you nail the boards back down again, double-check they haven't slipped underneath - getting trapped can be scary and dangerous for an animal.
Step 1
First, find any under-floor pipes or cables. One way to lift a board is to use a sharp, wide-bladed (at least 25mm) wood chisel and mallet to cut down through the tongues on each side.
Step 2
Another way is to use a floorboard saw. You can do this by holding the saw upside-down and working the curved tip of the blade back and forth to cut into the tongue.
Step 3
Once you've broken through the tongue, turn the saw over and continue cutting with the long edge of the blade. If the cut passes over a cable or pipe, use the curved edge of the blade again. If you work very slowly and don't apply too much pressure, you'll be able to control the blade as it breaks through the wood.
Step 4
Once you've sawn through the tongues on each side of the board, you should be able to see the joists below. If not, feel for them with a narrow-bladed tool. Use a pencil and try square to mark cutting lines across the board, in line with the edges of the joist.
Step 5
Take a large wood bit and electronic drill and drill a hole near one edge of the board so it just touches the cutting line across it.
Step 6
Put the blade of a pad saw into the hole and cut along the line to free the end of the board from the joist. Do the same at the other end, then the board should be ready to lift.
Step 7
As you've cut the ends of the board level with the joists, there won't be anything to nail or screw the board back into. You can get around this by nailing or screwing
