Borer, dry rot, damp, decay or just plain old age can play havoc with your flooring. To replace affected flooring first mark off the damaged area with chalk. Don’t order new material yet because you don’t really know how far the damage has spread or how thick the floor boards are.
Mark each board to the full extent of the visible damage and square off. The joists underneath can be established from the position of the nails.
Avoid having to cut on the joists, but estimate the work as close to them as possible. To establish a marking point, run a saw blade through the tongue of the board and keep it vertical until the teeth come against the joist.
Do this to two tongue and groove edges so that you know exactly where the line of the joist is, then mark it with a straight edge. Repeat the operation at each end of the damaged area.
Next cut across the boards as near to the joist as possible. A jigsaw or a power saw are the best tools to use, but you can make the initial cut with a tenon saw and finish the job with a panel saw.
Punch all the nails in the affected area right through the full thickness of the boards, which will mean that the only thing holding the boards is the tongue and groove. Choose any joint in the affected area, then run your saw through a joint from end to end to sever the tongue.
Using a heavy broad-blade chisel, prise out the boards, but be careful not to damage the groove in the good area.
Now that the joists are exposed, make sure the nail heads are below the surface, Take away the pieces of damaged flooring that might be left and brush away all dirt and dust.

Nail sections of hardwood batten to the sides of the joists and make sure the top of the batten is flush with the top of the joist. Nail the battens in securely, as these will be supporting the new floor boards.

At this stage it is a good idea to check the rest of the floor from underneath in case of any unseen damage, dampness or dry rot. If dry rot or damp is extensive, seek expert advice. But meanwhile, check your sub-floor ventilation, see that no earth is in contact with the brick-work above the damp course and that no water is lying in pools.
It is now worthwhile to check on that squeaky floor area, first where the joists are fastened to the bearers, and wedge if necessary. Also check where the bearers sit on stumps and again wedge if necessary.

When you are satisfied with the sub-floor inspection, you can order your new materials. Cut the new boards to the exact length and even undercutting a fraction as you do.
Set the boards in from each side of the hole and work into the centre. Try lifting the boards towards the centre while you put the last board in place, forming a springy arch.

Place a board across them and see if they spring into place. If they do, nail them down, keeping your weight on the boards as you do.
If this is not practicable, fit all the boards and cut the lower half of the groove off
one board to allow it to drop over the tongue of the next. Slightly bevel the edge to help guide the board into place.
Place a length of wood along the board and above the tongue, and use a heavy hammer to force it into place. Keep your weight on the boards while you are nailing them into place.

It is quite possible you may not be able to buy new flooring boards of the same width and thickness as the ones you have to remove. Sizes have changed with the introduction of the metric system.

If the board you buy is not the same width as that removed, cut a piece to fit. To get it to fit, cut the tongue and groove from the two boards between which the strip is to go. Cut the strip to fit tightly and bevel the edges. Then, using a block of wood and a hammer, force it into place. To avoid splitting the strip use fine nails or drill nail holes beforehand.

If the new boards are not as thick as the old ones, the solution is to use some form of packing on top of the joist so the tops of the boards finish flush. Thin strips of wood or malthoid cut to size will suffice.

Tools Required
Hammer, nail – punch, jig saw, panel saw, drill, drill bits, rule, pencil, chalk, heavy chisel, sharp chisel, plane.

If the new boards are thicker than the old ones, mark the position of the floor joist on the underside of the new boards and check them down to the required thickness before setting them into place.
Punch home all the new and old nails in the room to help eliminate any squeaks and plane or sand off any high spots. Plug up any gaps in the flooring, using a wood filler.
The final touch is to liberally sprinkle the bare flooring with talcum powder and brush it in to the cracks as much as possible before putting down underfelt. This is another precaution against squeaky floors.

Squeaking Floor
Nothing is more aggravating than a squeaking floor and the trouble is often difficult to cure. But here are methods which may help.

  • First, try to establish why the floor is squeaking. The most common cause is that nails have come loose through the timber shrinking over the years. If so, find the general area and punch the nails deeper. Use extra nails if necessary.
  • As an extra precaution against the squeaking recurring, get under the floor and drive home fine wedges between the boards and the joists. This can also be done if the floor is covered and you can’t get at the nails from above because of carpets.
  • If there are several boards loose, nail a cleat on to either side of the floor joist. Maintain a firm upward pressure while fixing the cleat.
  • Care must be taken with nailing when you are working on a polished floor. Drive the nails in at an angle to gain a firmer hold. Use a nail punch to set them below the surface. Fill the holes and refinish.
  • Finding the area of the squeak is relatively easy. But you could strike trouble if the area is covered with carpet, linoleum or parquetry and there is no room below the floor to work. The floor coverings might have to be removed, but first try this method.
  • Take a solid piece of wood and place it on the floor over the affected area. Rap the block solidly with a hammer while moving the block in a rectangular pattern. This may solve your problem.