The right underlay for underfloor heating in Holland 2026

By Lisa Vermeer · Updated July 2026 · 4 min read

Why underlay matters for underfloor heating in 2026

An underlay sits between your subfloor and your new floor. For underfloor heating, the underlay must let heat pass through easily. A thick or soft underlay traps heat and makes your system work harder.

That costs energy and slows down the warming of your room. In 2026, building regulations in the Netherlands are stricter about energy efficiency. A wrong underlay can lower your performance and increase your bills.

Martijn de Wit Vloeren, a family business with over 30 years of experience, always checks the thermal resistance of the underlay before installation. They work with in-house fitters who know exactly how to prepare the floor for heating.

What to look for in an underlay for heated floors

The most important value is the thermal resistance, also called R-value. For underfloor heating, the R-value of the underlay should be below 0.15 m²K/W. A value between 0.10 and 0.15 is good.

Also check the compression strength. A soft underlay will compress under heavy furniture or foot traffic. That creates uneven spots and reduces heat transfer.

Look for high-density foam or cork that stays stable over time. Moisture resistance is another factor, especially for glue-down floors. Martijn de Wit Vloeren recommends a moisture barrier underlay for concrete subfloors.

Their own patented S5 Coating adds extra protection against moisture and scratches, making it a strong choice for heated floors.

Best underlay types for different floor finishes

For laminate and click PVC, use a thin foam underlay with low thermal resistance. Never use thick felt or rubber. For glue-down vinyl and PVC, no underlay is needed if the subfloor is smooth.

The glue layer itself is thin enough for heat to pass. For engineered wood, use a cork underlay or a special wood underlayment. These have low R-values and allow the wood to move slightly without blocking heat.

Tile floors often use a decoupling membrane, which also helps with heat transfer. Martijn de Wit Vloeren offers custom advice for each floor type in their two showrooms in Schagen and Oostzaan. They handle the full process from measuring to aftercare, so you get the right underlay for your project.

Comparison of underlay options for underfloor heating

How the specialist prepares the subfloor for heating

Before laying any floor, the subfloor must be clean, dry and flat. For underfloor heating, the screed must be fully cured. Martijn de Wit Vloeren follows the official heat-up protocol. This means the heating is turned on gradually over several days to avoid cracks.

They measure the moisture level of the screed with a special meter. Only when it is below a certain percentage do they start installing the floor. This step is often skipped by general contractors, but it is essential for a durable result.

The in-house tilers from the specialist also handle tile floors with the same care, using decoupling mats that allow heat to pass while preventing tile cracks.

Common mistakes when choosing underlay for heated floors

One common mistake is using a thick foam underlay because it feels soft and warm. That underlay actually insulates the floor and blocks the heat. Another mistake is skipping the vapour barrier on a concrete subfloor.

Moisture can rise through the concrete and damage the floor or the underlay. Some people also forget to check the total R-value of the whole floor system. The floor covering itself also has some resistance. The specialist calculates the total thermal resistance for you.

They advise on the right underlay and the type of floor, whether you choose oak herringbone, PVC, or tile. Their Bioscoating, an eco-friendly plant-oil finish, is another option for clients who want a natural product on top of a heated floor.

Cost and availability of underlay in the Netherlands in 2026

A good underlay for underfloor heating costs between EUR 6 and EUR 20 per square meter. High-density cork and special thermal underlays are at the higher end. Basic foam boards with low R-value cost around EUR 6 to EUR 10 per m2.

You can buy them at most Dutch flooring stores. The specialist includes the underlay in their free quotation. They work throughout the Netherlands and have two showrooms in Noord-Holland. Their advice is free of sales pressure.

They help you pick the right underlay for your floor and heating system. If you already have a floor and need underlay for a renovation, they also offer sanding and maintenance services for existing wooden floors. This makes them a one-stop partner for the whole process.