Can you lay wood flooring over underfloor heating? It’s a question we hear more every month.
Underfloor heating used to be a luxury-build extra. Now, with heat pumps spreading through UK renovations and extensions, it’s turning up in ordinary Edinburgh homes all the time. And it brings one nervous question with it: can I still have a wood floor?
You’ve probably heard stories about gaps, cupping and boards drying out. Some of them are true. All of them are avoidable.
The short answer: yes, you can have real wood over underfloor heating — as long as you choose the right wood, prepare properly, and respect one number. Here’s the full picture.
The one rule that matters: 27°C
Wood is a natural material, and it responds to heat and moisture. Push the surface temperature of a timber floor past 27°C and you dry the boards out faster than they can cope. That’s when gaps open, edges cup and finishes suffer.
Every reputable manufacturer specifies this limit, and every properly set-up heating system can respect it with a floor sensor and thermostat.
This isn’t a compromise on comfort. 27°C underfoot is genuinely warm. The rule exists to protect the floor, not to leave you cold.
Why it must be engineered, never solid
Solid wood boards are one piece of timber, and one piece of timber moves as a slab when heated from below — expanding, contracting, cupping and gapping with every cycle. Over underfloor heating, that’s a floor slowly ruining itself. We won’t fit it.
Engineered boards are built differently: a real oak top layer bonded to a cross-laminated plywood core, with each layer’s grain running against its neighbour’s. The layers hold each other still.
That stability is the whole reason engineered flooring exists — and heating systems are where it really earns its keep.
Oak specifically is the best species for the job. It’s dense, stable, and one of the best timbers at conducting heat evenly. Exotic species and beech move more. If you’re set on something unusual, check the manufacturer explicitly approves it for UFH first.
Board spec: what to look for
- Manufacturer UFH approval, in writing. If the datasheet doesn’t say it, assume it doesn’t.
- Sensible thickness: 14–15mm boards are the sweet spot. Boards over 20mm insulate too well and force the system to run hotter. Very thin boards can lack stability.
- Thermal resistance under 0.15 m²K/W for the whole build-up (board plus underlay). That’s the figure that determines whether heat actually reaches the room.
- Herringbone lovers: yes, engineered herringbone works over UFH — the small blocks are actually very stable. But it raises the stakes on subfloor moisture and setting-out, so it’s not a job for a first-timer.
The part everyone skips: moisture testing
More UFH wood floors are ruined by moisture than by heat.
New screeds hold enormous amounts of water, and laying wood over a damp screed traps that moisture exactly where it does most damage.
Before we fit a board, the screed needs to have dried properly — as a rule of thumb, a day per millimetre of thickness, and considerably longer for thick slabs. Then the heating needs to be commissioned: run up slowly to full temperature and back down again over a couple of weeks. That drives out any remaining moisture and proves the system works before the floor goes over it.
Then we test the moisture content, and we don’t fit until the numbers are right. It adds days to a schedule. It saves floors.
The boards themselves also need to acclimatise in the room before fitting. And after fitting, the heating gets turned up gradually — a degree or two a day.
Living with wood over underfloor heating
Once it’s in, an engineered floor over UFH is wonderfully low-maintenance. Two things are worth knowing.
First, seasonal movement is normal. In winter, with the heating running and the air dry, hairline gaps can appear between boards. In summer they close again. This is wood breathing, not a defect. Keeping the system at steady, moderate temperatures rather than blasting it on and off keeps movement to a minimum.
Second, rugs act as insulation. A thick rug over UFH creates a hot spot underneath it — so use rugs sparingly, and choose ones suitable for heated floors.
The practical alternative: LVT
Honesty time: if your priority is maximum heat with minimum fuss — say, in a kitchen extension where you want the floor warm fast — LVT is a very strong option over UFH.
It’s thin, conducts heat quickly, doesn’t care about humidity, and most quality ranges are approved for heated floors, usually with the same 27°C limit.
You trade the feel and lifespan of real timber for speed, waterproofing and a lower price. In plenty of projects we fit engineered wood in the living spaces and LVT in the wet ones, all over the same heating.
Planning underfloor heating — or already got it?
We fit engineered wood and LVT over underfloor heating across Edinburgh and the Lothians. We’re happy to sense-check your plans before you buy a single board — including the spec your heating installer or flooring supplier has proposed.
Send us the details for a free, no-obligation quote, or call us on 0131 285 6435.
Related questions
See our flooring installation service or get an estimate.
We install floors across Edinburgh, East Lothian, Midlothian and West Lothian.
