All LIGNORA engineered oak floors are compatible with underfloor heating. Solid wood is not suitable. The sweet spot for performance over a UFH system is 14–18mm engineered oak — thick enough to feel substantial underfoot, thin enough to transfer heat efficiently and flex with the seasonal changes that UFH environments produce.
Short answer: Every engineered oak floor we supply works with UFH. Any thickness from our range. 14–18mm gives the best balance of warmth transmission and long-term stability. Solid oak is excluded. We confirm compatibility in writing before every UFH installation.
The sweet spot for UFH installations. Thin enough to conduct heat efficiently without significant lag. Thick enough for a quality feel underfoot and at least one future sand and refinish.
All engineered oak in the LIGNORA range is compatible with UFH systems, regardless of thickness. Thicker boards above 20mm will have slightly higher thermal lag — the floor takes longer to warm up — but will perform correctly within the specified temperature limits.
Solid hardwood is not suitable for installation over underfloor heating. The movement in a solid board in response to the temperature and humidity cycles of a UFH system is too great to be managed safely — gapping, cupping and joint failure are near-certain outcomes.
The relationship between floor thickness and UFH performance comes down to thermal resistance. A thicker board insulates more — which means it holds heat back from the room and requires more energy to reach a comfortable surface temperature. A thinner board conducts more freely, but may feel less substantial underfoot and has less material available for future refinishing.
14–18mm sits at the point where both problems are solved. Heat transmits effectively — typically reaching equilibrium within the manufacturer-specified system warm-up time. The floor feels like a proper wood floor. And the 3–4mm wear layer typical of boards in this range means the floor can be sanded and refinished at least once in its lifetime, which solid thin boards cannot.
Above 20mm, the floor still works — but the heating system has to work harder and energy efficiency is reduced. Below 14mm, you gain thermal efficiency but sacrifice the solidity and refinishability that make engineered oak worth installing in the first place.
| Recommended thickness | 14–18mm engineered oak |
| Maximum floor surface temp | 27°C |
| Maximum water temp (wet UFH) | 45°C flow / 35°C return |
| Minimum acclimation period | 48–72 hours on-site before install |
| Preferred fixing method | Full-spread glue-down |
| Floating installation | Compatible with UFH-rated underlay |
| Moisture barrier | Required on concrete/screed subfloors |
| Solid wood | Not suitable — any thickness |
| VOC compliance | All products certified — safe above UFH |
| Warm-up protocol | Written schedule provided at handover |
The underfloor heating system must be commissioned and running at normal operating temperature before any flooring is installed. A cold screed that then heats up after the floor is laid will cause movement that the adhesive bond cannot accommodate. We check that the system has been running for a minimum of 14 days before we start work.
The system must be turned down to 18°C at least 48 hours before installation begins — not off, just reduced. This prevents thermal shock when the floor goes down. The warm-up protocol after installation then brings the system back up gradually over 7–10 days.
The floor must acclimatise in the property with the UFH running at reduced temperature — not in an unheated garage or van. The timber needs to adjust to the actual ambient conditions it will experience once installed, including the drying effect of the heating system on the room's humidity.
After installation, the system is brought back up to operating temperature in stages over 7–10 days. Jumping straight to full temperature causes rapid moisture loss from the boards which can lead to gapping. We provide a written warm-up schedule specific to the product installed, and follow up to confirm it has been followed.
Provided in writing at handover for every UFH installation.
Heating remains off for 24–48 hours immediately after installation to allow adhesive to cure. Room should be ventilated normally.
System switched to low — 18°C surface temperature. Hold for two full days. Do not increase until the floor has had time to adjust to initial heat.
Increase to 21°C surface temperature. Hold for at least two days. Check floor for any early signs of gapping — minor movement is normal at this stage.
Bring to full operating temperature — not to exceed 27°C surface. This is the maximum for any engineered oak floor, regardless of product. Do not exceed.
We confirm UFH compatibility in writing before every job. Get in touch with your system type, subfloor and room dimensions and we'll advise on the right product and fixing method.