How do I lift a floorboard without breaking it?

Almost all floorboard damage happens in the first thirty seconds, from levering at the wrong point or sawing through a cable. Both are avoided by looking before cutting.

Safety

What you'll need

• An oscillating multi-tool with a plunge blade
• A bolster and a wide pry bar
• A cable and pipe detector
• A nail punch and pincers
• Scrap timber to protect adjacent boards
• Screws for refitting

Step by step

1. Work out what type of board it is.Square-edge boards simply butt together and lift with a bar. Tongue-and-groove boards interlock and the tongue has to be cut before anything will move.
2. Find the joists.The lines of nails across the floor mark them. Joists are usually at 400mm or 450mm centres and run at right angles to the boards.
3. Scan for cables and pipes.A detector along the intended cut line, and take the reading seriously. Cables are frequently stapled to the joist sides right beneath the board edge.
4. Isolate the electricity if you are cutting near a suspected run.It costs nothing and it is the difference between a nuisance and a serious injury.
5. Cut the tongue on both sides.A multi-tool with a plunge blade set to just deeper than the board thickness, run along both edges of the board you want out. A floorboard saw does the same job by hand.
6. Set the blade depth carefully.Just through the board and no more. A blade set 20mm too deep is exactly how cables get cut.
7. Cut across over a joist centre.If the board has to be cut across, do it over the middle of a joist so both the piece you remove and the piece that stays still have half a joist to sit on.
8. Punch the nails through rather than pulling them.Punching the heads through the board lets it lift without the nail tearing a chunk out of the surface. The nails stay in the joist and are pulled afterwards.
9. Lever with the load spread.A bolster in the cut with a scrap of timber under the bar, so the leverage bears on a wide area of the neighbouring board rather than crushing its edge.
10. Work along the board.Lift 10mm at a time in several places rather than pulling one end right up. A board levered at one point splits along the grain.
11. Label and note the orientation.Pencil the board number and an arrow on the underside. Boards are not interchangeable in an old floor.
12. Screw it back rather than nailing it.Countersunk screws into the joists hold better than nails, do not work loose, and mean the board can be lifted again without any of this.
13. Support a cut end.Where a board was cut mid-span, screw a timber batten to the side of the joist to give the cut ends something to bear on.

Tips

• Lift the board nearest the wall first if you can. It usually has less nailing and it gives you a view along the void before you commit to cutting anywhere else.
• Take a photograph down the void before you close it up. It is a permanent record of where the pipes and cables run.
• Screwing boards back down is the single change that makes future work easy and stops the floor creaking.

Common mistakes

• Setting the saw blade deeper than the board — Cables and pipes sit immediately below, often within a few millimetres of the underside of the board. A blade set too deep cuts them, and a cut cable under a floor is dangerous and expensive to find.
• Levering at one end of the board — All the force concentrates on a short length and the board splits along the grain, usually through the tongue. Working along the length in small increments lifts it intact.

If it doesn't work

Questions people ask