How to Replace a Wooden Floorboard
Where a floorboard has become too damaged to repair, you may want to replace it – or at least the damaged section. If you are removing the whole floorboard, you should be able to lift it up by inserting a bolster chisel and levering the floorboard, using a small block of wood as a fulcrum. A floorboard will lift more easily by springing the centre of the board, rather than starting at the end. If the floorboards are tongue and groove, you will have to cut through the tongues on both sides first – with either a floorboard saw or a powered circular saw, set so that the blade just passes through the tongue but does not hit the joists below.
To remove a section, lever up a whole length, so that you can make a cut across the floorboard directly above the middle of a joist, using a floorboard saw.
When you have the old floorboard up, check the width and thickness of the replacement board you need to buy. Hopefully, this will be a standard size: if the available board is too wide, you will have to plane it down; if it is too thick, you can reduce the size of the joists with a chisel or a rasp, so that the board fits; if it is (slightly) too thin, place strips of hardboard or plywood on top of the joists to bring the floorboard level with its neighbours. Cut the new board to the exact length.
Once the board fits exactly, drill two pilot holes to take the nails at each joist position. If the joists have a pipe or cable run across or through them, make sure any nails are well clear of these. Hammer the nails home.
Paint and varnish can be removed from floorboards using paint stripper or a heat gun. Remove old polish with white spirit and steel wool. If you intend to have the floorboards looking completely natural (with just a coat of varnish to seal them), you may have to hire a floor sander to clean them first. This is by no means an easy tool to use, so make sure you get proper instruction from the hire shop. Make sure all protruding nails are hammered down before you start. Work through the abrasive papers, sanding at an angle to the floorboards when using coarse abrasive, and in line with the boards with medium and fine. Hire an edge sander for the areas next to the skirting boards.