Floorboards can sometimes be so badly damaged that they cannot be repaired. In this case they need to be replaced with fresh boards. The new boards should be exactly the same thickness and width as the old ones. Modern floorboards are usually around 10 centimetres wide and around 1,9 centimetres thick, but the boards in old houses may be significantly thicker.
Sometimes it is impossible to find wood which is identical to the existing boards in colour and thickness. In this case, it is advised to have them cut to size by a professional or by the supplier, or to sand them down using an industrial sanding belt. In most cases sanding will be sufficient and will decrease the thickness of the board quite adequately.
In all other cases use slightly thinner timber and raise it by laying scraps of hardboard or plywood on the joists, and hold them in place with panel pins and nail the board on top. If only one or two boards are being replaced, then it is advised to buy square-edged boards. If the floor is made with tongue-in-groove boards and several of them are defective, then purchase new boards of the same type. Care must be taken however not to confuse the floor boards with the tongue-in-groove cladding which is normally used for decorative purposes on walls and ceilings, as this is made of much lighter materials and is not robust enough for flooring.
Lay Tongue and groove as follows:
1. Shave off the tongue of the first board with a plane
2. Lay it in position and butt its former tongued edge to the groove edge of an existing
board. The groove will be filled with the tongue of the old board which has been removed
3. Lay the second board on the joists and tap into place
4. Continue this process with the other boards
5. Shave off the tongue on the last board as well, as placing it will be difficult with the tongue intact.
6. Fix the boards to the joists with nails – it will be possible to see the location of the joists by the existing lines of nails in the floor.