March 2026 · 5 min read
The Best Engineered Timber for Underfloor Heating in Australia
Hydronic underfloor heating is becoming standard in high-end Australian homes. Not all engineered timber can handle it.
Why engineered outperforms solid
Solid timber expands and contracts with temperature changes. Over hydronic heating, this movement causes cupping, gapping, and structural failure within 2-3 years. The thermal cycling accelerates the natural moisture exchange in solid timber, creating stresses that the wood cannot absorb.
Engineered timber with a multiply core resists this movement because the cross-laminated layers counteract each other. Each layer of eucalyptus ply is oriented at 90 degrees to its neighbour, creating a balanced construction that remains dimensionally stable through heating cycles.
What to look for in the specification
The critical factors are:
• Total thickness: 12-15mm is ideal. Thinner boards heat faster but may lack rigidity. Thicker boards are more robust but reduce heating efficiency.
• Wear layer: minimum 3mm for longevity. A 3-4mm wear layer allows 2-3 refinishing cycles over the floor's lifetime.
• Core construction: eucalyptus multi-ply provides the best dimensional stability. Avoid HDF or particle board cores over heating — they are more susceptible to moisture-related swelling.
• Finish: UV-cured lacquer or hardwax oil. Both perform well over heating, but lacquer requires less maintenance.
Temperature limits
Keep water temperature below 28°C at the floor surface. Higher temperatures accelerate drying and can compromise the adhesive bond between the wear layer and core.
A good thermostat with floor sensors is essential. The sensor should be embedded in the screed, not the room, to ensure accurate surface temperature monitoring. Gradual temperature changes — no more than 2°C per day when ramping up or down — protect both the timber and the adhesive bond.
Installation method
Full-spread adhesive is the only recommended method over underfloor heating. Use a flexible MS polymer adhesive rated for heated applications.
Floating installations create an air gap that acts as insulation, reducing heating efficiency by up to 40% and causing uneven heat distribution. The air gap also allows moisture to accumulate beneath the boards, which accelerates deterioration.
All Maison Oak tones are hydronic heating compatible. Our installation guide includes detailed instructions for heated subfloor applications.