Underfloor Heating & Wood Floors
Despite the concerns expressed by those with less experience in this area, we are confident that with the right preparation and a suitable product our wood flooring can be successfully combined with underfloor heating. Our underfloor heating guide covers all the information necessary to make underfloor heating and wood floors work together.
The advice contained within this underfloor heating guide is the result of considerable experience over many years and covers the system types most commonly used by our clients, but this is an evolving industry so please make your underfloor heating supplier aware of our recommendations and discuss any queries with our technical team.
The first and most important step is to make sure your underfloor heating supplier is aware that a wooden floor is to be fitted over their system and that it is designed so that the surface temperature under the boards will not exceed 27°C. We would strongly recommend specifying combined floor/air thermostats to ensure that this is the case. This is not expensive and provides a reassuring back up that overrides the underfloor heating system if for any reason the maximum floor temperature is reached and protects the floor.
When combining underfloor heating with a wooden floor from Broadleaf, make sure that the selected flooring product is marked as suitable for use over underfloor heating in our flooring selector and has been ordered as re-kilned if necessary – this will be marked on your invoice.
As with any other installation, the site and subfloor must meet the basic criteria laid out on our Site Preparation page.
The heating must then be run for 3 weeks before the timber is delivered, at normal room temperature unless the ambient room temperature is too high to activate the thermostat at this level.
In this case raise the thermostat temperature so that the heating comes on to warm the screed. Although this may cause some discomfort in the summer months it is vital to ensure the evaporation of latent humidity. At this stage, make sure that the water temperature at the manifold is set to the specified temperature (this is normally 40°- 45°C for wood floors) and that the floor thermostat is set as master with a maximum of 27°C.
Timber should then be acclimatised as normal with the heating set at normal room temperature.
Fixing methods for water systems set in screed
To secret nail when underfloor heating is involved, either battens will need to be set into the screed, or it will need to be overlaid with tongue & grooved 18mm ply. Inset battens will need to be notched to allow the pipe to run across the floor and must sit at least as high as the surface of the screed. If you require further guidance on setting battens into a screed, please contact our technical team.
To glue fix boards, use Broadleaf Utra Adhesive and then proceed as normal. To glue fix parquet blocks, use Broadleaf Utra Adhesive as normal then undercoat and leave with the heating running normally for a period of 3 weeks for any initial settling movement to take place before filling, sanding and finishing as normal.
Strata boards can be floated over fibreboard underlay in this situation as normal.
Fixing methods for dry water systems
Where a water system is set between joists with conductor plates to transfer the heat, we recommend 18mm tongue and grooved ply be laid over the joists to prevent ‘hotspots’. Traditional boards can then be secret nailed or glued to this as normal, Strata boards can be floated and Parquet can be glue fixed as for systems set in screed.
Where a water system is set into a floating timber subfloor, this should be overlaid with 18mm tongue & grooved ply. Boards can be secret nailed with 38mm portanails (always test your nailer on a spare piece of ply before you begin to ensure that the nails do not breach the underside) or glued with Broadleaf Ultra Adhesive. Strata boards can be floated and Parquet can be fixed as noted for screed systems above.
To fit Traditional boards or Parquet over electric underfloor heating systems, first overlay these with 18mm tongue & grooved ply and then glue or nail as for dry water based systems above. Strata boards can also be floated over these systems as normal.
Note: If you are overlaying a system with 18mm ply and this is not part of the standard floor construction recommended by your underfloor heating supplier, you should make them aware of this.
Running the Heating
The night before your flooring is installed, turn the thermostat down so the heating is not actually warming the surface of the floor and maintain this status while the flooring is fitted.
Once fitting is complete, increase the thermostat temperature by a degree per day until you reach normal running temperature. Thereafter, ensure that temperature changes are gradual.
If you follow the advice offered in this underfloor heating guide, you should find that underfloor heating and wood floors can indeed exist together. Should you have any specific queries about underfloor heating or wooden floors, please contact our technical team...
- Tel: 01269 851 987