If a floor is damaged or old beyond repair, chipboard can be used to replace it effectively and cheaply. Chipboard is easy to work with and is less expensive than a timber floor. Flooring grade chipboard must be used.
Flooring chipboard is available in two thicknesses, and the builder must ensure that the correct thickness is used for the particular floor. A good guide is that if the centres of the floor joists are forty six centimetres or less apart, then the thinner chipboard is adequate.
The most common sheet sizes are two hundred and forty four centimetres by one hundred and twenty two centimetres, and also two hundred and forty four centimetres by sixty centimetres. As chipboard weighs a lot, it is advised that the smallest sheets available are used. A helping hand or an assistant may be required to assist with the carry and installation of the boards. Flooring chipboard can be bought with either tongued-and-grooved edges for simpler installation, or with square edges for a saving in cost.
Before starting the job, locate the positions of the joists under the floor. These could be indicated by a line of nails in the floor where it was fastened to the joists, but it is usually advised that a board is taken up to confirm the location of the joist. The sheets should be fixed to the joists with nails which correspond to the thickness of the board.
Work out the thickness of the sheets to suit the joist spacing, and the number of boards required to cover the area. It is advisable to use the boards soon after delivery and not to store them, as they can often be distorted by incorrect storage. Before laying the boards, put them flat in a pile inside the house, and at least 24 hours before work is started, loose lay them around the area to be covered so that they can adjust to the moisture content.
If access may be needed in future to a cable junction or plug, then fix the sheet above it with screws, which are much easier to remove than nails.