
Our customers are often relieved to finally find a company that knows what they are talking about! We have lots of experience with supplying wooden floors to be used over underfloor heating and we can share the benefit of our experience with you.
The most important point to realise is that any wooden floor is subject to expansion and contraction, according to the amount of moisture in the immediate environment. Hardwood boards may contract slightly during winter months (as central heating produces a much drier atmosphere) and expand slightly during the summer when windows are open and the atmosphere within the house has more moisture. This seasonal movement is a normal characteristic of wooden floors and it never stops - regardless of the age of the wooden floor. This expansion and contraction can also be magnified when dealing with underfloor heating as the wood is subject to a higher than usual temperature and degree of moisture loss. Please use the following fact and figures to determine the suitability of use of Chauncey’s Tectonic Engineered boards. We have further information on our Chauncey’s Blog about the importance of house climate when using wooden flooring over UFH. Please note that it is important to keep relative humidity in rooms within the range of 40%- 60% RH.
| Facts and Figures (using TECTONIC® OAK FLOORING) | |
|---|---|
| Floor Top Surface Temperature: Max in use | 27° |
| Floor Underside Temperature: Max in use | 40° |
| Heat Output Max. in use | 75W/m2 |
| Floor Uneveness Max. | 3mm in 3m |
| Floor joists & Ply Substrate mc (if appicable) Max: | 12% |
| Distance of hot water pipes below boards (in screed) Min: | 30mm |
| Distance of hot water pipes below boards - Min: | 3mm |
| Subfloor / Room temperature at time of installation: | 15-24° |
| Subfloor ERH (equilibrium relative humidity) at time of installation: | 40-65%RH |
| ARH (ambient relative humidity) at time of installation: | 40-60%RH |
| Joist spacing (if applicable) Max | 400mm |
| Edge Expansion joint Min: | 12mm |
| Thermal conductivity of TECTONIC™ 20 mm: | λ = 0.17 W/mK |
| Thermal conductivity of TECTONIC™ 15mm: | λ = 0.17 W/mK |
FITTING OUR BOARDS OVER UNDERFLOOR HEATING:
We would always recommend using a professional floor fitting company, such as Chauncey’s Floor Fitting Services, who will install both the UFH and the engineered flooring.
If the UFH is within concrete screed then gluing boards using either SIKABOND or Rewmar flexible adhesive is the best method to ensure a rapid heat transfer.
If battens have been laid, then the flooring can be secret nailed to this, but great care must be taken around any areas close to the pipes. It may be advisable to use SIKABOND T2 glue (supplied in cartridges) to glue boards to any battens that are close to pipes to ensure that there is no damage to the pipes from nails.
TECTONIC™ Oak Flooring can be laid as a ‘floating floor’ (i.e. where the T&G joints are glued together to form a floating layer over the solid subfloor). However, this is not the best choice for installing over UFH as any air gaps left when installing ‘floating’ boards will act as barrier to the heat transfer. If your subfloor is absolutely flat then floating may be a viable option using a specialist underlay which will aid the transfer of heat.
For more information on fixing Chauncey’s floors please look at our YouTube films.
We always recommend Chauncey’s TECTONIC® Engineered wide plank flooring for use over underfloor heating. (see above).
TECTONIC™ Engineered flooring has a unique structure; layers of high-quality, water-resistant birch ply are glued together in opposing directions to form a base resistant to movement and finished with a kiln-dried, solid hardwood layer.
You can choose to have either an overlay board of 15mm thick (11mm ply + 4mm oak wear layer) or a structural thickness board with a total thickness of 20mm (14mm ply + 6mm oak wear layer). TheseTECTONIC™ boards give the appearance and the durability of a solid wide oak board, but ensure much better stability.

The boards can be supplied unfinished, leaving you the opportunity to apply a lacquer or oil of your own choice. We can also hand-finish these boards with lacquer or oil if a pre-finished board is required
TECTONIC™ Engineered flooring has been successfully used in many projects and with different types of underfloor heating and it is very resistant to movement. It is advisable to stack and acclimatise the boards as per our instructions to ensure the TECTONIC™ boards remain as stable as possible. TECTONIC™ boards can be floated or glued directly to screed floors (using a flexible adhesive) or secret nailed to battens/joists.