Badly worn boards can often be taken up and reversed with the neven side downwards. The joists are then packed with thin slips of wood where necessary. The boards which have curled edges should then be planed level, planning in the direction of the grain of the wood.
A thorough cleansing of the boards comes next. Grit and dirt are best removed with soap and scrubbing brush. This will probably reveal some stains, which will not yield to ordinary cleansing, and these stains must be removed or they will show through the stain. A good bleach will probably remove most of them, while glass paper and plane may be used to erase any that remain. Make up a bleach by mixing American potash and water together to make a paste, or use one of the proprietary bleaches such as parazone, durazone—spread the paste over the stain and leave for some hours, then rinse away with cold water.
The floors of many houses built between the two wars were made from unseasoned wood and by now have developed gaps between the boards, as much as 14 in. wide. Besides being very unsightly, these gaps cause draughts. Therefore the next stage must be to fill in such gaps. It is convenient to fill in nail holes at the same time.
There are several methods which may be used, depending upon the extent of the gaps. If the gaps are large, they may best be filled in with strips of plasterer's lathes—these are approximately 3 ft. long, about 11/4 ins. wide and about /4 in. thick. The lathe must have a few shavings taken off so that it is wedge-shaped at one side as in Fig. 23- The lathe is then glued and driven into the gap between the boards, so that a small portion of the lathe protrudes above the surface. This must afterwards be planed level and sandpapered. Another method of filling large gaps is by making a form of papier mache. This is done by tearing newspaper into small pieces and boiling them in sufficient water to cover them. Paste or glue must then be mixed with the pulp. A sticky putty-like substance will result.