How do I restore an old parquet floor?

A parquet floor found under carpet or vinyl is one of the genuinely worthwhile discoveries in an older house, and restoring one is a satisfying job. It is also considerably more work than sanding boards: there are far more joints, the grain changes direction every block, the blocks are often loose, and the adhesive underneath needs treating with respect.

Safety

What you'll need

• a floor sander and edger, hired
• a full range of abrasives
• flexible flooring adhesive
• replacement blocks, ideally reclaimed (optional)
• filler suited to fine joints
• a floor finish suitable for high traffic

Step by step

1. Uncover and assess before committing.Take up the covering and any underlay, and remove staples, gripper and adhesive residue. Then tap the whole floor and mark every hollow area. If more than a modest share is loose, the job is a re-bedding job with sanding as an afterthought, and the cost changes.
2. Deal with the substrate and any damp.Parquet is usually on a concrete slab or a screed. Test it. A wet slab is the reason most parquet floors fail and it must be resolved before any block is re-bedded.
3. Re-bed loose blocks and replace missing ones.Work methodically, keeping blocks in their original positions. Reclaimed blocks of the same species and thickness fill gaps far better than new; check the thickness carefully because a proud or low block shows badly after sanding.
4. Remove old adhesive residue from the surface only after identification.Bitumen smears on the face of the blocks come off during sanding, but if the bedding is unidentified black material, get it tested before you generate any dust.
5. Sand diagonally to the pattern first.Because the blocks alternate direction, there is no along-the-grain option. Working diagonally to the block pattern cuts both grain directions equally and levels the floor. This is the key difference from sanding boards.
6. Work through the grits, changing direction between the coarse stages.A common approach is a first diagonal pass one way, a second diagonal the other way with the next grit, then finer grits following the dominant pattern direction. Take it steadily — parquet loads a machine much harder than a board floor.
7. Expect to use far more abrasive than a board floor.The end grain in a herringbone or basketweave pattern blunts abrasive quickly. Change belts far more often than you would on boards, because a blunt belt burns rather than cuts and burnished parquet will not take finish evenly.
8. Fill the joints if the floor wants it.A resin filler mixed with the floor's own fine sanding dust fills the many small joints and gives a continuous surface. Some restorers deliberately leave the joints open for a more traditional appearance — decide before the final grit.
9. Finish with a product that suits a jointed floor.Hardwax oil is popular on parquet because it is repairable in patches and does not form a brittle continuous film over hundreds of joints. A hardwearing lacquer gives a tougher surface but is harder to spot-repair.

Tips

• Photograph the pattern before you lift anything. Herringbone, chevron, basketweave and brick patterns are easy to reassemble wrongly at a border.
• The border blocks around the edge of a parquet floor are often a different size or a different species. Keep them separate and put them back where they came from.
• Reclamation yards sell parquet by the square metre, often from the same era and species as yours. Buying a small surplus of matching blocks now is much easier than finding them in five years.
• If the whole floor lifts easily, consider that it may be worth lifting completely, cleaning the substrate properly, and re-laying — a far bigger job, but the only route to a floor that will not keep coming loose.