Wooden/laminate flooring and water-based underfloor heating

Efter att golvvärmesystemet har installerats och provtryckts är det dags att lägga trägolv / laminatgolv.

Make sure that the underfloor heating is:

• Level and dry
• Free from floor and other residue
• The floor panels must be securely attached to the subfloor. If a panel is loose, wobbles or makes any noise against the flooring, secure it further with screws or similar

When wood flooring is laid on the underfloor heating system, it is vitally important to remember to follow instructions about expansion joints. Underfloor heating means that the wood dries out to a greater extent during the period when the heating is on than where underfloor heating has not been installed. It is therefore important to limit the underfloor heating’s installed capacity and to increase the size of the expansion joints size by approx. 50% if they are specified for cases where there is no underfloor heating. Underfloor heating will cause slightly larger gaps to appear between the boards during the driest winter months. Instructions on how to lay the wooden flooring are available from your floor supplier.

Industry guidelines can be downloaded from the flooring industry association (GBR) website www.golvbranschen.se in the form of a manual entitled “Trägolv på golvvärme” [“Wooden flooring on underfloor heating”] (GBR, version 2005:2). As a rule, durable polyethylene film (building plastic 0.2 mm thick) is laid on top of the underfloor heating system. Polyethylene film must comply with SPF (Sveriges Plastförbund) Verksnorm 2000/2001. Then gray rag paper, Airolen (plastic foam) or cork-backed paper is laid on it. Gray rag paper is the preferred option from an energy perspective as this product is less insulating than the others.
Insulating spacers lead to increased ground losses, less heat dissipation upwards and higher system temperatures (water temperatures). Finally, the floor covering is laid so that it “floats” on top of the above-mentioned layers.

Water-based underfloor heating with engineered wood flooring

Engineered wood flooring is laid as per the supplier’s instructions. Flooré panels are usually covered with durable PE foil. Then gray rag paper is laid. The engineered wood flooring is laid so that it “floats” on top of the gray rag paper.

Water-based underfloor heating with laminate flooring and click flooring

Some laminate floors are coated underneath with rag paper and a vapor barrier. Despite this, we recommend durable PE foil. Follow the floor supplier’s instructions.

Water-based underfloor heating with solid wood (floorboards)

The wooden boards should be laid at right angles to the main direction of the coil. In the direction of the grain, the wood’s thermal conductivity is about twice that in the radial direction. Using the wood’s properties in this way provides a more even surface temperature. Installation is carried out according to the floor supplier’s instructions, which are generally described in the section for Wood products.