These instructions are strictly for use with Wunda systems only — using them with any other system may result in serious performance issues, system failure, or invalidation of your warranty.
Wood floor Coverings
Contrary to many people’s beliefs you can use wood with underfloor heating. However, it is important to remember that wood is a natural insulator so won’t be as effective at spreading the heat as a natural conductor would be. The only two types of wood you cannot use with underfloor heating are maple and beech. It’s always important to be safe and check with your flooring supplier if the flooring can be used with underfloor heating.
Most wood floorings should not be heated beyond 27 degrees, our floor heating systems should be limited and controlled by a floor probe for each zone that you intend to have wood flooring. Make sure you tell us what floor coverings you intend to use within your project, so we know to include a probe in your system.
These guidelines have been created to help you confidently install wood floor coverings over your Wunda Rapid Response® boards as part of a complete Wundafloor® system.
When installed correctly, your Wundafloor provides a stable, efficient, and highly responsive heated floor designed to work seamlessly with wood floor finishes.
Wood Flooring with Underfloor Heating
Here are a few things to understand when considering your choice of wood flooring.
Wood is a natural insulator and its properties will reduce the heat output, the thicker wood the greater the impact.
To ensure efficient heating, the total thermal resistance of the chosen wood should be less than 2.5 Tog (an R-value of 0.25 m²K/W).
While solid wood can be used, engineered wood is often a preferable option. Its multi-layered construction offers enhanced stability when subjected to temperature fluctuations.
It is important to note that Maple and Beech woods are not suitable for use with underfloor heating. Be sure to consult your flooring supplier for thermal resistance details and suitability for use with water based underfloor heating.
Your wooden floor finish can be installed on the Rapid Response boards in a number of ways. In order for a smooth process, please take into account the following guidance:
Preparation:
Please ensure the wood is allowed to acclimatise before installing, check your suppliers’ instructions for more details. In order to protect your floor, it is necessary to use a room sensor or thermostat that has a facility to accommodate a floor probe, which is positioned directly under the floor finish prior to laying the wood flooring. This will be set to cut out the heating at a floor surface temperature of 27°.
Installation Method 1 – Free Floating
The first and most popular is for it to be free floated using a suitable underlay. We provide a 2mm breathable XPS underlay with an R value of approx. 0.056m²K/W.
Installation Method 2 – Bond Direct
Secondly, the floor finish can be bonded directly using approved high temperature wood adhesive from Mapei, Ultrabond Eco S955 1K.
*Only for when the flooring manufacturer recommends it is bonded
Installation Method 3 – Self Levelling Compound
Thirdly, an approved self levelling compound could be used on top of the Rapid Response® panels. Then, the wood floor finish can be laid on top. When doing small form factor blocks, like parquet blocks in a herringbone or chevron pattern. It is recommended to use one of the approved levelling compounds as an intermediate layer. Floor probes must be installed within any levelling compound at the upper surface and flush with the levelling compound upper surface.
It is important to carry out a pressure test of the floor heating system and pipes prior to applying any primers and levelling compounds.
Before pouring any levelling compounds, ensure that all Rapid Response boards are securely bonded to the subfloor and that there is no movement in the boards. Additional Secure fixing of the boards may be required using large washers and screws, if movement is detected. It is important that any movement in the boards or joints between boards is addressed and remedied before levelling compounds are poured.
The aluminium of all unused pipe channel’s must be cut to expose the empty channel, ready for filling with your chosen levelling compound.
It is crucial to always prime the boards first with the approved and relevant primer, before laying the approved self levelling compound.
The Approved Self Levelling Compounds Are:
‘10mm Ultra ProLevel Ultimate’, when primed using ‘Ultra Prime it multi surface primer’.
‘10mm Mapei Ultraplan Renovation Screed’ when primed with ‘Mapei Eco Prim Grip’
The levelling compounds and primers are not provided by Wunda. They can be sourced from local merchants or online and the relevant ratios will be included on their instructions.
Self Levelling Curing time
Tile adhesives and levelling compounds/screeds must be allowed to cure naturally. Be sure to check the manufacturer’s specific requirements. Do not use the underfloor heating system to accelerate the curing process. When activating the heating, increase the temperature gradually. If you have a mixing valve begin with the it set to the minimum position and increase slowly by up to 5°C each day until the desired operating temperature is reached. If you are coming from a low temperature heat source, ensure the flow temperature supplied is low to start and slowly increased by up to 5°C each day until the desired operating temperature is reached.
Installation Process
When laying the floor finish, an expansion gap needs to be incorporated around the perimeter, please be sure to check your supplier’s instructions. If possible, try to ensure the wood runs at 90° perpendicular to the pipe runs to avoid joins running parallel with the pipes. This isn’t essential but good practice and it should have already been communicated to the Wunda team at the design stage and reflected in your board and pipe layout plan.
Floor Probe
The floor probe protects your flooring from overheating, cutting off the flow if it ever gets too warm. The floor probe needs to be in contact with the floor finish. When doing a self-levelling compound, allow the compound to cure and ensure the floor probe is placed on top, allowing it to be in contact with the floor finish. A small channel may need to be chased out of the compound to allow it to sit flat under the finish.
Download Wunda Rapid Response® floor coverings information