How to repair parquet: scratches, dents, open joints and cupped boards

What you need

• Vacuum cleaner and microfibre cloth
• Clothes iron and a damp cotton cloth
• 3 cm flexible plastic spatula
• Large syringe or glue injector with a thick needle
• 240 grit sanding block and fine abrasive pad
• Wood or room hygrometer (optional, €10-20 at Leroy Merlin)
• Hard wax sticks or a parquet repair kit in several shades (Leroy Merlin, Bricodepot)
• Touch-up pen or paint for parquet in the closest shade
• Flexible parquet filler, acrylic or wood-based (Ceys, Loba, Bostik)
• Parquet adhesive or D3 white glue (Titebond, Pattex)
• Water-based parquet varnish, matt or satin (Loba, Bona, Xylazel)
• Masking tape and weights or sandbags for pressing

Step by step

1. 1

   Work out what type of parquet you have

   Look at the edge of a board by the skirting board or at the threshold. If you see a single layer of wood about 14-22 mm thick, it is solid parquet and allows deep repairs. If you see 3-5 mm of hardwood on plywood, it is floating multilayer parquet: it only takes very light sanding and damaged boards are replaced.

2. 2

   Clean the area

   Vacuum and wipe with a microfibre cloth and a little specific parquet cleaner. Avoid mopping with lots of water: parquet cannot cope with puddles or soaking mops.

3. 3

   Surface scratches: wax or pen

   If the scratch does not go through the varnish, rub it with a touch-up pen in the closest shade and buff with a cloth. If the bare wood is showing, soften a hard wax stick with a hairdryer, fill the scratch, remove the excess with the plastic spatula and buff with a dry cloth.

4. 4

   Dents and knocks in solid wood

   Put a damp cotton cloth over the dent and press with a dry iron at medium heat for 10-15 seconds. The steam swells the compressed fibres and lifts the dent. Repeat 2-3 times and leave to dry for an hour. If the varnish has cracked, touch it up afterwards with water-based varnish. Do not do this on thin multilayer parquet: the heat lifts the hardwood layer.

5. 5

   Open joints

   Vacuum the dust out of the joint. Fill with flexible filler in the wood shade using the plastic spatula, pressing inwards, and remove the surplus with a slightly damp cloth before it dries. A joint wider than 3 mm that reappears every winter means the wood is moving with the damp: do not fill more than 2-3 mm with rigid filler.

6. 6

   Loose or creaking boards

   If the board is glued down, find the spot that creaks and drill a 2 mm hole with a fine bit in the joint or somewhere hidden. Inject parquet adhesive with the syringe until it just overflows. Put weight on top (a sandbag or books) for 12-24 hours, protecting the floor with cardboard.

7. 7

   Cupped boards: measure and wait

   Before doing anything, check with a straightedge that the cupping is not getting worse. Look for the cause: a leak, rising damp, condensation on the ground floor, an over-wet mop. If it is water, cut off the source and let the floor dry for 2-4 weeks with the home ventilated or with a dehumidifier. Often the board goes back into place by itself.

8. 8

   Sand and level only if it has gone back down

   If a small ridge remains on a solid board after drying, sand the varnish on that board with 240 grit, following the grain, and apply two coats of water-based varnish in the same sheen, with a light rub of the abrasive pad between coats. On multilayer parquet do not sand: replace the board.

9. 9

   Replace a damaged board

   Cut the board along the middle with a jigsaw or multi-tool, take the two halves out towards the centre and remove the tongue from the new board on the side that fits into the neighbour's groove. Apply glue to the tongue and seat the board with gentle taps from a wooden block. Weight on top for 24 hours.

10. 10

    Seal and protect the finish

    With the parquet dry, apply a coat of water-based varnish over the repaired areas, feathering the edges. Do not walk on it for 12 hours and do not put furniture back for 48. Fit new felt pads on the chair legs so they do not scratch it again.

What is wrong with your parquet: diagnose before you repair

Parquet damage almost always falls into four groups. Scratches and scuffs are marks in the varnish or the top layer of wood. Knocks and dents come from dropped objects or heels and compress the fibres. Open joints appear when the wood shrinks in dry air or with heating. And cupped or wavy areas (boards with raised edges) almost always come from damp: leaks, condensation or cleaning with too much water.

Before buying anything, check whether the parquet is solid or multilayer, glued to the subfloor or floating, and how much hardwood is left. Thin-layer parquet that has already been sanded several times will not take any more. A quick test: put a drop of water on an unvarnished patch of wood. If it soaks in within seconds, the finish is worn and the wood will thank you for a maintenance coat of varnish.

Common mistakes when repairing parquet

• Mopping with lots of water. It is the number one cause of cupping. Use a well-wrung mop and a neutral cleaner.
• Sanding thin multilayer parquet. A 3 mm hardwood layer is sanded through in a minute and cannot be saved.
• Filling joints with rigid filler. The wood moves with the seasons and the filler falls out. Choose flexible filler.
• Gluing cupped boards without waiting. If the floor is still damp, the glue will not grip and the board lifts again.
• Using car wax or silicone cleaners. They leave a film that stops varnish taking afterwards.
• Not looking for the source of damp. If the lounge parquet cups next to a kitchen wall, check the waste pipe, the washing machine and the plumbing first. You can see how to trace damp on a wall.

When to call a professional

Repairing a scratch or a joint is simple. It becomes carpenter's work when several boards are damaged, the parquet is glued to the subfloor and has to be lifted, the cupping covers more than 1-2 m², or boards in an old parquet have to be replaced and there is no spare. In those cases we measure the area, look for a spare board of the same type (sometimes one can be taken from under a wardrobe) and fit it for a fixed price.

Our rates: first hour €35-45, following hours €28-35 for individual parquet repairs, and floating floor €10-15 per m² labour when a section of floating floor has to be replaced. Sanding and varnishing a whole floor is not something we do: we refer it to a renovation specialist.

See our carpenter service, carpenter prices and the guides on how to repair laminate flooring and how to lay laminate flooring. For another type of floor: how to lay vinyl flooring.

Coastal humidity and parquet in beach flats

On the Costa Blanca and in Valencia relative humidity goes above 70 % in summer, and parquet takes in and gives off water through the year: it widens in August and opens up in January. That variation explains most open joints and slight waves. A €10-20 hygrometer tells you whether your flat sits between 40 and 60 %, the range in which wood is settled.

In second homes that stay shut for months, the best approach is to air the property for a while each week and run a dehumidifier moderately. If you leave a flat empty in winter, tell a neighbour you trust: a leak from the flat above or a problem with a communal drain can flood a whole parquet floor in a weekend. A regular check on your second home catches it in time.