Timber floors do not often give much trouble, and such problems as do arise are frequently caused by the boards being lifted, for repairs to plumbing or electrical services under them, and improperly replaced. Many of these can be cured quite easily, with a few woodworking tools and a certain amount of upheaval, as carpets and furniture have to be moved to give access.
Repairing holes and gaps
Unless your floorboards will be on show, repairs to holes and gaps are carried out mainly to stop draughts and dust rising through them. Small holes can be stopped up with wooden plugs or wood filler; gaps between boards can be filled with thin strips of wood glued, tapped in and planed flush.
Large holes, usually the result of damage, should be cut out completely and replaced with new wood. If the boards are tongueand-groove, your first job is to use a padsaw to cut along the join between the damaged board and its neighbour, to sever the tongue. Next, the end of the board should be prised up with a claw hammer or floorboard bolster, once the nail heads holding it have been punched in. Wedge the end of the board up so that you can saw off the damaged section at the centre of the next joist along. Cut a piece of new board to fit the gap, remove the lower lip along its grooved edge and slot it into place, nailing it down to the exposed halves of the joists at each end.
An alternative method is to cut out the damaged section using a padsaw, cutting at an angle of 45° between two holes drilled in the board. The new piece of board is cut to fit, and is supported on fillets of wood screwed to the sides of the joists.
If the gaps between boards are sizeable right across the floor, it is better to fit and re-lay all the boards, nailing each One in turn tightly against its neighbour as you work. This process will leave a large gap along the skirting board at one side of the room, which should be filled with a new board cut down to the required width.
Boards that are improperly fixed squeak and bang when trodden on, and may warp, causing ridges to show through your floor-coverings. Nail down all loose boards securely; to force a warped edge back into place use screws, rather than nails which will be pulled up by the spring in the board.
If you want to clean up old floorboards and leave them exposed, you should hire a floor sanding machine. This is rather like a cylinder lawn mower, and rotates belts of abrasive paper against the floor surface, picking up the dust like a vacuum cleaner as it goes along.
Before using the machine, punch down all nail heads carefully, to prevent them tearing the abrasive belts. Then begin to sand the floor at an angle of 45° to the board direction, using coarse abrasive. Change to medium and finally to fine, running this time parallel with the boards. To reach right into the skirting boards, you will need a small rotary or orbital sander, again used with a selection of abrasive papers. Once the surface is completely stripped, sweep up carefully, and if you intend to paint or varnish the floor, wipe it over with a rag dipped in white spirit. Then you can apply the finish of your choice.
Re-screeding concrete floors
You can patch small areas of damage in concrete floors with a cement-based filler or ordinary mortar. But if the surface is crumbling and dusty, the best solution is to cover it with a new screed, using a self-levelling floor screeding compound. Sweep the floor to remove all loose material, mix up the compound with water as recommended, and pour it out on to the floor surface. Trowel it out to cover the entire surface; the mix is runny enough to level itself out, and dries to leave a hard, smooth surface layer a few millimetres thick, and the perfect base for new floor coverings.