Wood Flooring Over Underfloor Heating: What You Need to Know

Underfloor heating and real wood floors can absolutely live together, but the combination is less forgiving than tiles or vinyl. Get the board choice or the commissioning wrong and the floor will tell you about it within a season.

Engineered only, and check the rating

Solid wood is out: the heating cycle makes it cup and gap, and most manufacturers exclude it from warranty over underfloor heating. Choose an engineered board specifically rated for underfloor heating, and keep that paperwork. The rating tells you the construction has been tested against the heat cycle.

The rules that protect the floor

• Maximum surface temperature of 27 degrees C at the floor, lower is kinder
• Commission the heating before the floor goes down: screeds must be fully dry and the system run through a heat cycle first
• Bring the temperature up and down gradually, a few degrees a day, never blast it
• Keep indoor humidity steady, ideally 40 to 60 percent, especially through winter
• Glue-down fitting usually transfers heat better than floating, but follow the board maker's guidance

Board width and species matter

Narrower boards are more stable than wide ones, and oak is more stable than beech or maple. The fashion for very wide planks fights physics here: a 220mm wide board over heating will move more than a 140mm one, whatever the brochure says. If you love wide boards, accept the need for careful temperature control.

What goes wrong, and when

The classic failure is a winter gap pattern: the heating goes on hard in October, the boards dry and shrink, and gaps open along the edges. Most close again in summer if the damage is mild. Cupping, where board edges lift, means moisture imbalance and needs investigation, not filler. Cracking along the grain means the floor got too hot or too dry, and it is permanent.

Getting it right from the start

The successful jobs all share the same pattern: right board, dry subfloor, commissioned heating, gentle temperatures. We fit wood floors over underfloor heating across Hampshire as part of our flooring work. Call 07983 630628 to talk through your setup before you buy.