How To Install Underfloor Heating On Floorboards

Underfloor heating is a great way to heat your home and save money on energy bills. How to install underfloor heating on floorboards is the perfect way to retrofit your home and it’s the easiest and quickest way too, especially if installing an electric underfloor heating system. In this guide, we look at how to install underfloor heating on floorboards and the different types of timber floors and floorboards.

Different types of floorboards to consider for underfloor heating

The term, ‘timber floorboards’ refers to solid natural wood and this is very likely to be found in the majority of properties. More modern properties may have chipboard panels, which are a type of reconstituted wood such as block board or veneered wood such as plywood boards. Wood underfloor heating can be installed under all types of timber floorboards including formed and veneered wooden boards.

Underfloor heating for timber floors

Underfloor heating works well with all types of timber floors and because wood is a conductor of heat it has a high heat transfer rate. That said, there are a few things that need to be considered. Wood, in all its formations, is susceptible to movement. That’s because when wood gets warm it is likely to expand and then it will contract when it cools.

Placing underfloor heating below floorboards that have expansion gaps between them shouldn’t be a problem. Underfloor heating installed below sheet timber or engineered timber is very often less liable to warping. It is, however, a good idea to leave a narrow expansion gap between the boards as a safeguard. To prevent problems, as a general rule, the temperature for all types of wood flooring should not exceed 27°C

Underfloor heating for suspended timber floors

More often found in older houses, a suspended timber floor has a space below it. It usually consists of wooden floorboards attached to wooden supporting joists, which are positioned just above the foundations. Both electric and wet underfloor heating systems can be installed to suspended timber floors using special supporting plates and thermal insulation boards. The work can usually be carried out by removing the wooden floor boards or if there is sufficient space beneath the floor then the work can be carried out from below.

Underfloor heating for engineered wooden floors

Underfloor heating can be installed beneath engineered wooden floors, which offer more stability over timber floorboards. Engineered wood floors consist of a top layer of solid wood with several softwood layers below. These layers add strength to the flooring and allow it to naturally expand and contract rather than warping, twisting or cracking as can be the case with a solid wood floor.

Common methods for installing your underfloor heating on floorboards

There are several ways, in which underfloor heating on floorboards can be installed. Most are best suited for underfloor heating for engineered wooden floors. Some are best suited to wet systems, which can be quite involved and take some time to install. Whereas, electric underfloor heating is a much quicker installation option. Some of the most common installation techniques include the following.

Floating technique

The floating technique refers to a method of installing a floor that isn’t attached to the subfloor. Instead, it relies entirely on the weight of the floor to maintain its position. This is a quick and easy method but is only suitable for engineered hardwood flooring surfaces that are laid on a suitable underlay.

Adhesive technique

The adhesive technique refers to gluing the timber floor surface to the sub-base or sub-floor. This is most often used when installing a wet underfloor heating system. The glue is very flexible and allows for movement of the timber surface as it warms and cools. A glued floor also helps to prevent air pockets from arising, which can lift parts of the surface. This can be particularly noticeable on laminate flooring surfaces.

Battening technique

Another common method for laying underfloor heating with a timber floor is the battening technique. This involves fitting heat distribution plates between existing joists or fitting a batten framework to the sub-floor for supporting the new flooring surface. This method is suited to both wet and electric underfloor heating systems but is especially suitable for attaching a batten framework to a level screed sub-base.

Maintenance steps to help your underfloor heating on floorboards to settle

Underfloor heating for timber floors will be either a wet or an electric underfloor heating system and both need a little maintenance to ensure you get the most from your UFH system in terms of efficiency and energy cost savings. A newly installed system with a timber floor surface may need time to settle down so here are a few recommended steps you can take to ensure you get the most from your new UFH system and timber floor surface.

• The first thing is to ensure you keep your floor surface clean and free from clutter to ensure there is adequate heat transfer into the room.
• Ensure the thermostat is programmed correctly and that sufficient heat is rising through the floor surface. A programmable or smart thermostat is best for this type of system.
• Wooden floor surfaces should not be allowed to heat up beyond 27°C. Operating your underfloor heating system above this critical temperature can cause permanent damage to the floor.
• Check the floor surface area to ensure it is evenly warm. Any cold patches could indicate trapped air in the system, which will need to be bled out.
• If the underfloor heating system has been turned off for any length of time, for example, during the summer months, then it’s best to gradually increase the temperature over time instead of just turning it on full in the winter. This will help prevent any ‘shock’ to the timber.
• Inspect the wooden or laminate floor covering regularly and check for any damage or lifting. Also, check the UFH system connections including the wiring, and check the valves and manifold if you have a wet UFH system.

More information is available about the types of underfloor heating for wooden floors and more in-depth help, advice and guidance is available on our knowledge hub page.