Everything you need to know about underfloor heating and wooden flooring
We are often asked about the suitability of using wooden flooring with underfloor heating. Provided a suitable type of floor is chosen, and care is taken at the installation stage, wooden flooring and underfloor heating will work well together. In this blog, Russwood’s Flooring & Interior Cladding Supervisor, Thea Jones, answers some commonly asked questions on the subject covering species, installation advice and more.
Which type of wooden flooring is best for use with underfloor heating?
Timber flooring is sold as either solid or engineered boards. Engineered boards are the best choice for use with underfloor heating due to the increased level of stability they afford. Solid Oak can also be used, but requires greater care with site preparation and installation. Engineered flooring is also a little thinner than solid, allowing heat to transfer more efficiently.
Russwood’s range of engineered oak flooring, which is created from multiple layers of birch plywood topped with solid oak, is ideal for use with underfloor heating. The top layer of oak – known as the lamella – is thick enough to ensure that the floor will last a lifetime. The cross-glued multi-ply backing, constructed solely from birch, greatly increases the stability of the board. Birch is a longstanding favourite of furniture and cabinet makers due to its lack of knots, inherent durability properties and immense strength when layered together and bonded into ply.
How should I store my floor after delivery?
It is important that the flooring is stored correctly after delivery and allowed to acclimatise before laying. In all cases we recommend that the flooring is first unwrapped from all polythene and then stacked in order to allow air flow. It should then be acclimatised in the room that it is being laid (or a room with a similar room temperature and relative humidity) to allow the wood to reach an equilibrium with its surroundings.
How do I prepare for installation of my floor?
It is vital that the heating is on prior to installation, and that the air humidity levels are approximately 40-65% relative humidity. Ideally, the wet trades (plastering, painting and plumbing) should be complete prior to introducing the floor to the room. This is very important as wood is hygroscopic, meaning it tends to absorb and release moisture from the air around it. If there is an excess of moisture or extreme lack of moisture in the air, the boards may expand and contract excessively. To allow for seasonal variations in temperature and different levels of heating, leave an expansion gap of at least 15 mm all around the perimeter of the floor (skirting can then be fitted over the gap or a plinth strip used if existing skirting is still in place).
If fitting onto underfloor heating, we recommend acclimatising the floor for one additional week whilst the underfloor heating is turned on. If fitted onto a new concrete sub floor, make sure to check that it is at a moisture content lower than your flooring before the floor is delivered. Moisture content should always be checked prior to installation.
What’s the best method of fitting flooring with underfloor heating?
We recommend fitting to a heated screed with the fully bonded method using Tover Tovcol MS Adhesive. Tovcol MS is suitable for use with underfloor heating allowing maximum heat transfer, and creating a solid feel underfoot. It is a high-performance bond which remains flexible, in order to enable seasonal expansion and contraction of the boards. Its early quick grab allows working on the newly installed floor, without boards slipping or the need for tape. It is very easy to work with and extrude, plus, it’s compliant to stringent environmental standards. A 100% Solvent-free formula, it is moisture resistant, has easy surface clean up and is virtually odourless.
Detailed instructions on how to prepare for your flooring installation can be found here.
For more expert technical advice on our flooring, or to discuss the specifics of your own project, please get in touch with our flooring team.