Wood floor fillers close gaps, cracks and knot holes before a floor is sealed, and the right one depends on how the gap formed and what's going on the floor afterwards. We stock resin fillers, water-based fillers and wax filler sticks from Jenkins, Osmo, Morrells and Junckers, in clear and coloured options to match different wood tones. Resin fillers are mixed with your own sanding dust for a colour-matched fill on gaps between boards, while wax sticks handle smaller repairs on a finished floor without any sanding at all. Call 020 8830 9785 if you're unsure which type suits the repair you're doing.
Which type of wood floor filler do you need?
Resin fillers are the standard choice for filling the gaps between boards or blocks during a sanding and refinishing job. They're mixed with the dust collected from sanding the floor itself, which means the filler comes out matching the exact colour and grain of the wood rather than a generic shade. Solvent-based resin fillers dry fastest, some setting hard within half an hour, which keeps a sanding job moving. Water-based versions take longer to cure but suit floors that will later be finished with a water-based lacquer, since compatibility between the filler and topcoat matters for adhesion.
Wax filler sticks work on the opposite end of the job. They're for small, localised repairs, a chip, a nail hole, a scratch or gouge on a floor that's already finished and isn't being resanded. You melt or press the wax into the damage, level it off, and it blends into the surrounding finish. Soft wax sticks are easier to work into fine cracks and small holes, while hard wax sticks hold up better in areas that see more foot traffic.
| Filler type |
Used for |
When it's applied |
| Solvent-based resin |
Gaps between boards, mixed with sanding dust |
During sanding, before finishing |
| Water-based resin |
Gaps between boards on floors getting a water-based finish |
During sanding, before finishing |
| Wax filler sticks |
Small chips, holes, and scratches |
On an already-finished floor, no sanding |
One thing worth knowing before you start: gaps wider than about 2mm are usually too big for a standard resin filler to hold reliably over time, especially with the seasonal movement solid wood floors go through. For wider gaps, strip filling with wood slivers before applying resin filler gives a more durable result.
FAQ
Can I use wood floor filler on gaps that open up every winter? Small seasonal gaps that close again in summer are usually best left alone, since a rigid filler can crack or pop out as the wood moves. Filler works best on gaps that stay consistent year-round.
How long does resin filler need to dry before sanding it back? This varies by product, but solvent-based resin fillers are often ready to sand within 30 minutes to an hour, while water-based versions typically need longer. Check the specific product's guidance since drying times differ between brands.
Will the filler colour match my floor exactly? Resin fillers mixed with your own sanding dust give the closest match, since the colour comes from your actual floor rather than a pre-tinted formula. Wax sticks come in a range of shades and work best when you pick the closest match and blend at the edges.
Do I need to seal over wood floor filler? Yes. Filler used during a sanding job gets sealed along with the rest of the floor as part of the normal finishing process. If you're doing a spot repair with a wax stick on an already-sealed floor, the wax itself is the final surface and doesn't need a separate topcoat.
