Wooden floors are a popular choice for many new builds or renovations as their timeless look pairs well with clean, modern kitchens and worktops. Timber flooring is suitable for use with underfloor heating and also provides good visual warmth for any room in your house.
Because wood is a natural product it reacts to the surrounding atmosphere and this an important consideration when selecting timber flooring for your home. Certain woods are less susceptible to movement than others, so always check with the supplier that your choice is suitable for use with underfloor heating.
It is advisable to ask for the recommended maximum base/surface temperature of the timber, in order for Nu-Heat to factor this into your heating design, ensuring you will achieve sufficient output to heat the room.
While wooden floors are suitable for underfloor heating, we always recommend using engineered wood for your wooden flooring with a UFH system. Engineered wood gives the same effect as solid hardwood but with the added benefits of strength and durability once it is laid.
Benefits of engineered wood for underfloor heating
Engineered hardwood flooring is the most compatible wood flooring for underfloor heating systems and it looks exactly the same as solid wood flooring. Once you have installed it, it feels the same underfoot, too. In fact, the top part of the engineered wood plank is made from solid wood, but the underneath has base layers which give strength and stability; allowing your floor to expand and contract with the daily changes in temperature delivered by underfloor heating.
The majority of renovations and new builds use underfloor heating and wooden floors together because you get the real warmth from the underfloor heating system combined with the aesthetic warmth that a wooden floor brings to a home.
What’s more, it’s easy to find an engineered hardwood floor to complement any space. There’s a wide range of wood, grain patterns, colours, plank sizes and surface finishes to choose from; making engineered wood flooring a versatile and resilient flooring option.
There are many benefits of choosing to pair your underfloor heating system with engineered wood:
- An engineered wood floor looks just like a solid wood floor.
- The construction of engineered wood flooring makes it more stable than solid wood floor coverings.
- You can install engineered hardwood flooring at any floor level, including below street level. In contrast, solid hardwood floors cannot be installed in basements.
- Engineered wood floors are often considered to provide a more high-end finish laminate flooring and cheaper than comparable solid wood planks.
- Engineered wood flooring is highly durable and long-lasting.
What types of wooden flooring are suitable for underfloor heating?
We recommend using engineered wood floorboards with our underfloor heating systems due to their strong structural design. Engineered board, made up of layers laminated together, is a more stable product than solid timber. The recommended board width of the engineered wood when going over underfloor heating is 150mm.
For parquet flooring over underfloor heating, solid wood is not recommended and only engineered timber parquet should be used.
Care should always be taken to make sure conditions on site are suitable for both acclimatising and laying any timber floor. Timber flooring is not suitable for use with underfloor heating when a high heat output is required.
For solid hardwood floorboards, it is always best to use a kiln-dried timber with minimum moisture content, usually between 6-9%. Store it in a dry place before installation and fit a floor temperature sensor to avoid the timber overheating.
Moisture will cause floorboards to warp and change shape over time. Kiln dried timber with minimum moisture content will retain its shape during seasonal climatic changes and resist the temperature change that comes with an UFH system.
Because of this, any solid wood timber floorboards should not be brought onto site until all excess moisture has been removed from the building, as it may be adsorbed causing the timber to warp. Always follow the flooring supplier’s advice on acclimatisation.
Solid timber can be used with underfloor heating in some circumstances although narrow boards are recommended. Solid timber should not be used when a high heat output is required from the underfloor heating.
How to best install underfloor heating and wooden floors
There are a few important considerations to bear in mind when installing wooden flooring over underfloor heating systems.
Leave an expansion gap during installation
Always leave an expansion gap around the edge of the room, typically 15mm. This allows the floor to expand and contract with atmospheric changes and will usually be hidden by skirting.
Fixing methods for engineered and solid wood floors
Solid timber and engineered wooden floorboards are designed to be slotted together – usually tongue and groove – and can be reinforced using glue. These floorboards can be ‘floated’ over the sub-floor where the boards are not fixed down. This method saves on time and labour and makes the flooring more resistant to changes in humidity and temperature.
To bond timber floorboards to the underfloor heating, adhesives can be used to provide a secure seal between the wooden flooring and the concrete screed. Always check with the flooring supplier for their recommended primers and adhesives.
Battening is when timber battens are fixed across the floor prior to screeding. When the screed is fully dry the timber flooring can be attached to the battens using a screw/plug or secret-nail fixing. Care must be taken not to damage the floor heating pipe when nailing or screwing into the battens.
Warming up the floor for the first time
When heating up your underfloor heating system for the first time, it’s really important to warm the system slowly to minimise the risk of shocking the timber floor. Turn the heating mixing valve (or heat pump maximum flow temperature) to 40˚C, and then increase the temperature by 5˚C per day up to the design temperature.
For more information on wooden flooring with underfloor heating, please get in touch.