How do I stop a floor being cold underfoot?
Seal the gaps first, insulate if you can, and use rugs and underlay for everything else.
- Difficulty
- beginner
- Time
- 1 hr
- Read
- 2 min
- Safety
- caution
Short answer
Seal the gaps between floorboards and around the skirting first — most of the cold is draught rather than the floor itself. That costs very little and it is the change people notice most.
A cold floor is usually two separate things: air coming up through gaps, and a cold surface. The draught is cheap to fix and accounts for most of the discomfort, so it is worth doing before anything expensive.
Safety
Step by step
- Find out whether it is draught or cold surface.Hold a hand near the floor on a windy day, or use a candle near the skirting. Moving air is a draught problem; a merely cold surface is an insulation problem. They have different fixes.
- Seal the gaps between floorboards.Flexible filler, gap-filling strips or a proprietary sealant designed to move with the boards. In an old house this alone transforms how a room feels.
- Seal around the skirting.The gap between skirting and floorboards is often the biggest single draught in a room, and it is completely hidden. Decorator's caulk along the join.
- Keep the airbricks clear.The void under a suspended floor must stay ventilated. Blocking airbricks to stop draughts causes rot, which is a far more expensive problem.
- Use good underlay under carpet or laminate.Underlay contributes more to warmth and comfort than the flooring above it. It is the part people economise on and the part they feel.
- Insulate under the floor if you have access.From a cellar or crawl space, insulation between the joists is very effective. From above, it means lifting boards, which is a bigger job — see the floor insulation guide.
- Add rugs.The cheapest and most immediate improvement. A large rug with a good underlay changes a room substantially and can be moved seasonally.
- Consider underfloor heating only during a floor replacement.Retrofitting into an existing floor is disruptive and expensive. If the floor is coming up anyway, it is the moment to consider it.
Tips
- Ground floor rooms over a ventilated void are the coldest. Upstairs floors over heated rooms rarely need any of this.
- Draught-proofing a floor also cuts heating bills. It is one of the few improvements that pays for itself quickly.
- Thick socks and a rug solve most of this for almost nothing. Not every problem needs a building solution.
Questions people ask
Why is my floor so cold?
Usually draughts coming up through gaps between boards and around the skirting, rather than the floor's temperature. Sealing those is cheap and it is what people notice most.
Can I block the airbricks to stop the draught?
No. The void under a suspended floor needs ventilation or the joists rot. Seal the gaps in the floor itself instead.