Parquet Sanding, Filling, and 3x Varnishing

Before work starts, the room has to be cleared: furniture, rugs and skirting boards. The fitter then checks the floor for loose or creaking blocks and signs of moisture. These spots need repairing before sanding. Otherwise the problem simply ends up hidden under the new varnish.

1. Coarse sanding with a large belt or drum sander removes the old varnish and levels out height differences between blocks.
2. Edges and corners are sanded with a smaller edging sander, where the big machine cannot reach.
3. Filling: a binder is mixed with the sanding dust from your own floor and the paste is spread over the whole surface with a trowel. This way the filler comes out almost the same shade as the wood.
4. Once the filler has dried, the floor gets a fine sanding, often with a rotary disc sander. This removes excess filler and evens out the surface.
5. The floor is vacuumed thoroughly so no grains of dust end up in the varnish.
6. The base coat seals the pores of the wood and prepares it for the next coats.
7. After drying, the surface is lightly sanded with a fine abrasive screen to remove raised grain.
8. Two top coats of varnish are applied, with the drying time between them kept as the manufacturer specifies.

Sanding is done in several passes, from coarse grit to fine. If the fitter skips a grit, the scratches from the coarser paper stay in the wood and the varnish makes them even more visible.

The price list also includes a related item. A full restoration covers sanding, filling the whole surface and three coats of varnish. The item "sanding of wooden parquet with varnishing" is mainly used when the parquet is in decent condition, has no noticeable gaps and only needs sanding and varnishing. The extent of filling and the number of coats vary between quotes, so ask exactly what is included before you place an order.

Which option you need depends on the state of the floor:

• Old solid parquet with gaps and deeper scratches almost always calls for the full job with filling
• A less worn floor without gaps can usually manage with sanding and varnishing
• In a hallway, kitchen or office it pays to insist on several coats of varnish even with the simpler option

The thickness of wood above the tongue also matters, as this is the layer that can be sanded away. Solid parquet usually withstands several restorations. Mosaic parquet and engineered floors with a thin top layer can only be sanded carefully, and sometimes not at all. Laminate and vinyl cannot be sanded.

Water-based varnishes are the usual choice for homes today. They have little smell, dry quickly and are suitable for children's rooms too. Two-component varnishes with a hardener resist wear better, so they are chosen for hallways, busy living rooms and offices. Solvent-based varnishes are hard but smell more and need thorough ventilation, so they are used less and less in homes.

The sheen affects both looks and upkeep:

• Matt looks natural and hides scratches and dust well
• Satin is an all-round compromise for most rooms
• Gloss brings out the grain of the wood, but every mark on it stands out

Oil is an alternative to varnish. It keeps the natural feel of the wood and can be repaired in patches, but it needs regular maintenance. If you have underfloor heating, ask the fitter about a flexible filler and a varnish the manufacturer recommends for that use.

The effort, and therefore the cost, depends mainly on the condition of the floor. More work is needed with:

• Several layers of old, hard or yellowed varnish
• Wide gaps, or loose or missing blocks
• Water-damaged areas and an uneven subfloor that has to be repaired first
• Hardwoods such as oak or ash, which use up more abrasive paper
• Rooms with many corners, alcoves and doorways
• A small area, where setting up and transporting the machines is spread over fewer square metres

On the other hand, an empty home, skirting boards already removed and a larger continuous area all speed things up. If you live in a block of flats, check the house rules and tell the building management or owners' association and your neighbours in advance, as sanders are loud. Refinishing a parquet surface does not normally need any permit. If the repair would change the floor build-up or affect the structure, check with your local building authority first.

In practice, a cheap or rushed job often only shows its faults after a few months. Watch out for these:

• A DIY sander in inexperienced hands leaves waves and over-sanded dips that cannot be undone
• Skipping the fine sanding leaves scratches visible under the varnish
• Sanding without dust extraction spreads dust through the whole home, and particles end up sealed in the varnish
• Not waiting long enough between coats causes peeling, bubbles or patchy areas
• Loose blocks that are not fixed move again over time and the varnish cracks along the joints
• Putting rugs down too early, or furniture without pads, damages the fresh varnish

Why does the timing of the job matter? Wood reacts to humidity. In very dry or very damp air it behaves differently, and the filler in the gaps can crack later. That is why restorations are often planned for spring or autumn, and while the varnish dries the room should not be heated hard or exposed to draughts.

Look at the finished floor in daylight and with side lighting, for example a torch held close to the ground. Check that:

• The surface is smooth and even, with no waves or circular sander marks
• There are no darker or rougher strips along the edges and in the corners
• Gaps are filled and the filler matches the colour of the wood
• No hairs, dust or bubbles are trapped in the varnish
• The sheen is the same across the whole floor, with no dull patches
• Blocks do not creak or move when you walk on them
• You have been told which varnish was used and when the floor can take full load
• You know which products to clean the floor with and how often to renew the protective layer