TL;DR — Wood Floor Gap Filling Cost At A Glance
- Wood floor gap filling costs £10–£25 per m² across most of the UK, rising to £12–£33 per m² in London and the South East.
- It is usually done as part of sanding, since fresh sawdust from the sand makes the ideal resin filler for a colour-matched result.
- Method changes the price: resin and sawdust is the standard, wood slivers or fillets suit wide gaps, and flexible caulk is a cheaper, temporary fix.
- Price depends on the number and width of gaps, the chosen method, floor area, and whether sanding is included.
- Filling gaps cuts draughts, dust and heat loss between floorboards, and it stops small items disappearing down the cracks.
- On its own, gap filling often carries a minimum charge; bundling it with a full sand is the most cost-effective approach.
Get a fixed price for gap filling — check prices and book online or arrange a survey to confirm the gaps and method.
Add to Preferred Sources How Much Does Wood Floor Gap Filling Cost In 2026?
Filling the gaps in a wooden floor costs £10–£25 per m² across most of the UK, rising to £12–£33 per m² in London and the South East. In practice, gap filling is rarely a standalone job — it is almost always done during sanding. The reason is practical: the fine sawdust produced while sanding your own floor is mixed with resin to make a filler that matches the timber's exact colour, so the filled gaps blend in rather than standing out as pale lines.
Gaps open up in older floors as boards dry out and shrink over decades, and the result is draughts, heat loss, dust rising from the void below, and the odd earring vanishing between the boards. Filling them is as much about comfort and warmth as looks.
Because the per-m² rate is modest, a gap-filling-only visit usually carries a minimum charge to cover the setup. If the floor is being sanded anyway, adding gap filling is inexpensive, which is why the two jobs are so often quoted together.
| What you are paying for | Rest of UK | London & South East |
|---|---|---|
| Gap filling with sanding (per m²) | £10–£25 | £12–£33 |
| Average room (15–20 m²) | £150–£500 | £180–£660 |
| Whole 3-bed floor (~60 m²) | £600–£1,500 | £720–£1,950 |
| Standalone gap filling | minimum charge applies | minimum charge applies |
Figures include VAT where applicable and reflect 2026 market rates. Your exact price depends on the floor and your postcode — get a fixed quote here.
Wood Floor Gap Filling Cost By Method
The method suits the width of the gaps and the look you want. Wider gaps need a more substantial fix than a resin paste can provide.
| Method | Best for | Relative cost | Notes |
|---|---|---|---|
| Resin & sawdust | Fine to medium gaps | Standard (£10–£25/m²) | Colour-matched, done during sanding |
| Wood slivers / fillets | Wide, even gaps | Higher | Timber strips glued in, then sanded flush |
| Reclaimed board strips | Very wide or period gaps | Highest | Matched aged timber, most labour |
| Flexible caulk / mastic | Draught-proofing on a budget | Lowest | Temporary, less discreet, flexes with the boards |
Gap filling is largely a labour cost. The resin and any timber slivers add modestly to the bill, but the time spent working filler into every gap and sanding it flush is the main expense. Flexible caulk is the cheapest route and good for stopping draughts, but it looks less refined and does not last as long as a resin or timber fill.
What Affects The Cost Of Wood Floor Gap Filling?
Several factors decide the final price.
1. Number And Width Of Gaps
A floor with a few hairline gaps is quick; a period floor where every board has shrunk apart takes far longer. Very wide gaps cannot be filled with resin alone and need timber slivers, which adds labour and material.
2. The Method
Resin and sawdust is the standard and most cost-effective when done with sanding. Wood slivers and reclaimed strips cost more because each piece is cut, glued and sanded flush. Caulk is cheapest but is a draught-proofing fix rather than a discreet repair.
3. Whether Sanding Is Included
Gap filling is most economical bundled with a sand, because the sawdust is free and the setup is shared. As a standalone job it carries a minimum charge, so a tiny gap-filling task can feel expensive per metre.
4. Floor Type And Age
Old softwood boards, parquet and reclaimed floors each behave differently. Period floors with heavy movement may need a mix of methods, and the specialist may advise leaving some flexibility so the fill does not crack as boards move seasonally.
5. Preparation
Deep gaps full of decades of dust and debris need clearing before filling, and any loose or squeaky boards are best re-fixed first so the fill lasts.
6. Location And Access
London and the South East run 20–30% higher than the rest of the UK, and upper floors or furniture that must be moved add time.
What's Included — And What's Not
| Typically included in a gap filling quote (with sanding) | Usually charged separately |
|---|---|
| Clearing debris from the gaps | Re-fixing loose or squeaky boards before filling |
| Mixing resin with sawdust from the sanded floor | Replacing split, rotten or missing boards |
| Working the filler into gaps and sanding flush | Wide-gap timber slivers or reclaimed strips (a different method) |
| Filler over the main floor area | Standalone filling without any sanding (minimum charge) |
| Draught-proofing skirting gaps and perimeter voids |
Ask the specialist which method suits your gaps, and be wary of anyone promising a rigid resin fill on a floor that clearly moves a lot with the seasons.
Can You Do It Yourself?
For a small floor with a few gaps, DIY gap filling is realistic. Ready-mixed wood fillers and flexible caulks are sold for exactly this, and pressing filler into gaps by hand saves the labour cost. Draught-proofing strips and caulk are a straightforward weekend job.
The limitation is the finish. DIY fillers rarely match the timber as well as sawdust from your own sanded floor, so filled gaps can show as darker or lighter lines. Rigid fillers on a moving floor crack and pop out within a season. Wide gaps really need timber slivers cut and fitted, which is skilled work. If the floor is being sanded anyway, or the gaps are wide or numerous, having a professional fill them at the same time gives a far better and longer-lasting result.
How To Save Money On Wood Floor Gap Filling
- Combine it with sanding, so the sawdust is free and the setup cost is shared.
- Use flexible caulk for a budget draught-proofing fix where looks matter less, such as under furniture or at the perimeter.
- Fill several rooms in one visit to spread the minimum charge.
- Clear and vacuum the gaps yourself before the team arrives to save prep time.
- Prioritise the worst gaps — perimeter and high-draught areas — if budget is tight.
- Get 2–3 quotes and compare the method, not just the per-m² rate.
How To Hire A Good Floor Sanding Specialist
Ask which filling method the specialist recommends for your gaps and why — a good one will match the method to the gap width and to how much the floor moves. Read independent reviews, confirm insurance, and get a written quote stating whether sanding is included. A specialist who understands timber will advise a flexible approach on a period floor rather than a rigid fill that cracks, and will re-fix loose boards before filling so the repair lasts.
Fantastic Services works with vetted, insured floor specialists and provides an up-front price — describe your floor and gaps to get a quote.
Restore the finish of your wooden floors with expert gap filling
Frequently Asked Questions
How Much Does It Cost To Fill Gaps In Floorboards?
In 2026, gap filling costs £10–£25 per m² across most of the UK and £12–£33 per m² in London when done as part of sanding. A standalone job carries a minimum charge, so filling gaps is far cheaper bundled with a floor sand.
What Is The Best Way To Fill Gaps In A Wood Floor?
Resin mixed with sawdust from the sanded floor is the standard, because it colour-matches the timber and sits discreetly. Wide gaps are better filled with wood slivers or reclaimed timber strips, while flexible caulk is a cheaper draught-proofing option that is less discreet.
Does Gap Filling Stop Draughts And Heat Loss?
Yes. Filling the gaps between floorboards closes the route for cold air, dust and heat loss from the void below, which noticeably improves comfort in older homes. Perimeter gaps at the skirting are worth draught-proofing too.
Should Gap Filling Be Done Before Or After Sanding?
It is done during the sanding process. The floor is sanded first to produce fresh sawdust, which is mixed with resin and worked into the gaps, then the floor is given a final sand so the filler is flush before sealing.
Will The Filled Gaps Crack Or Come Loose Later?
On a stable floor, a well-matched resin fill lasts for years. On a period floor that moves a lot with the seasons, a rigid fill can crack, which is why a good specialist may use a slightly flexible method or timber slivers so the repair moves with the boards.
Can Very Wide Gaps Be Filled?
Wide gaps are better closed with timber slivers or reclaimed board strips glued in and sanded flush, rather than resin alone, which would sink or crack. This is more labour but gives a solid, lasting result on floors with significant shrinkage.
