Gap Filling
Resin or timber-sliver gap filling for warmer, cleaner floorboards.
Gaps between floorboards are a natural part of an older floor. They let in cold air from under the floor, collect dust and can spoil the look of a freshly sanded floor. Filling them makes rooms feel warmer and cleaner.
Gap filling is normally done alongside floorboard restoration and our wider floor sanding service. This lets us sand the filler flush before finishing.
Resin or slivers?
Resin filler
Small gaps are filled with a resin mixed with your floor’s own sanding dust for a close colour match. It is quick, neat and ideal for stable floors.
Timber slivers
Wider gaps are filled with thin strips of reclaimed pine, glued into one side of the gap and planed flush. Timber moves with timber, so slivers cope better with wider gaps.
Important: gap filling and our guarantee
Timber floors move — they swell in damp months, shrink when the heating is on, and flex with the structure of the house. This natural movement means that filled gaps can crack or reopen. Gap filling is therefore excluded from our service guarantee. The sanding and finishing on the same floor is still covered by our 3-month guarantee.
Warmer rooms with fewer draughts
Fewer dirt traps between boards
A neater, more even finish
When to fill gaps
Not every floor needs it. Some customers like the traditional look of open joints, while others want a warmer, more uniform floor. If gaps are very wide or boards are rocking, it is usually better to lift and re-lay the boards tightly together. We will talk you through the choices during the free survey. Underfloor insulation is another option if draughts are the main concern.
Timing
Gaps are filled after the first sanding pass, once the boards are clean and the true width of each gap is visible. Once set, everything is sanded level with the boards before finishing. It usually adds half a day to a typical room.
Our article on resin or sliver gap filling explains the pros and cons. If boards are badly damaged, our floorboards repairs service replaces them first. See our prices for gap filling costs.
Guide prices
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Floor sanding & oiling
Dust-free sanding back to fresh timber, finished with two coats of hardwax oil.
from £22 per m²
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Floor sanding & lacquer
Full sand and three coats of hard-wearing water-based lacquer.
from £24 per m²
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Parquet sanding & finishing
Multi-direction sanding for block and herringbone floors, with your choice of finish.
from £28 per m²
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Gap filling
Resin filler or reclaimed pine slivers between floorboards.
from £6 per m²
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Floor staining
Colour samples on your floor and an even stain before finishing.
from £5 per m²
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Stairs stripping & restoration
Paint and varnish removal, repairs and finishing of treads and risers.
from £45 per step
Guide prices — we confirm a fixed price after a free survey.
Questions about gap filling
How should I prepare the room?
Empty the room where possible and take down curtains that reach the floor. We can help move heavy furniture if we know in advance. Our preparation checklist has more tips.
Does gap filling make a room warmer?
It usually makes a real difference. Gaps between floorboards let draughts rise from under the floor. Filling them makes rooms cosier and stops dirt collecting between boards.
Why is gap filling not guaranteed?
Our 3-month guarantee does not cover gap filling. Wooden floors expand and shrink with the seasons and with movement in the building, which can open small cracks in the filler. We use the most suitable method for your floor to keep this to a minimum.
How are your prices worked out?
Prices depend on the floor area, condition, repairs needed and the finish you choose. Our price list shows typical starting prices, and the free survey gives you a fixed written quote.
Are my original floorboards worth sanding?
Yes — original boards often hide beautiful timber under old paint and varnish. We knock down protruding nails, replace split boards and sand back to fresh timber. Read our guide to Victorian floorboards for what to expect.
Resin or slivers — which is better for gaps?
Smaller gaps are filled with resin mixed with fine sanding dust, so the colour matches. Larger gaps are best filled with tapered pine slivers, glued and planed flush. Our gap filling guide compares the two.
What our customers say
Great with our dogs around
“We wanted something that would cope with a lively dog. Their advice on a durable lacquer was spot on and it has held up brilliantly so far.”
Wealdstone
Love our new darker floor
“We were after a smoky grey-brown tone. They put down several samples on our own boards and helped us choose. The finished colour is even and rich.”
Pinner
Excellent work in our hall
“The team fitted the work around our weekly bookings, finished on schedule and left the hall spotless. The hall feels bright and welcoming again.”
Hatch End