Minor damage to parquet blocks and wood strips, such as deep scratches and cigarette burns, may be repaired by sanding the damaged area or the whole floor if necessary. If the damage is more extensive, you will have to replace the blocks; chop out the first block with a chisel and prise up subsequent blocks with a lever. When chiselling out parquet blocks, you should start from the centre and work towards each end, taking care the chisel does not cut into adjacent blocks.

Replacement blocks should be the same thickness as the original ones; slightly thicker ones can be planed down after laying but do not buy blocks which are too thin. It is quite difficult to place packing pieces to bring them up to the correct height. Clean and scrape the sub-floor leaving it dust free. Use a notched spreader to apply adhesive, either to the floor or to the back of the block. Some bitumen-based damp proofing liquids are suitable for fixing wood blocks.

The blocks should be tapped into place with a hammer after the adhesive has been applied; use a piece of scrap wood to protect the surface of the block. Wood strips are repaired in the same way as blocks, but lifting them from the sub-floor may prove more difficult. Often the strips are tongued and grooved along their length and they may be fixed with hidden nails (secret nailing), which are inserted at an angle through the tongues as the wood strips are laid. The best lifting method is to free one end of the strip in the manner described to chisel out parquet blocks. It may now be possible to lever up the strip along its length. If this is not so, you can use a circular power saw, set to cut three quarters of the distance through the strip, running down the centre of the strip.

By levering the strip in the middle at the chiselled end you should now be able to split the board into two and pull out each half. Fitting new strips is similar to flitting blocks; taper the sides of the strip inwards, so when it is hammered down it wedges into place along its length. If the strip is slightly proud of the surface after fixing, you can plane or sand it level.

If the floor is in good condition, you can improve its appearance and provide a durable, non-porous surface by applying a polyurethane sealer. Wash the floor thoroughly with household detergent and water to remove dust and grease, then rinse with clean water and leave the floor to dry. To remove polish and stubborn stains, you can use white spirit; but afterwards always wash with detergent and rinse with clean water to ensure there are no traces of spirit left on the floor.

If the floor is painted, you should hire a floor sanding machine and use it to strip the paint back to bare wood; then wash and rinse the floor as before. Apply the sealer, following the manufacturer’s instructions, and leave each coat to dry before applying the next (three coats should be sufficient); on the penultimate coat, use abrasive paper or wire wool to give a perfectly smooth surface for the final coat.