Common installation mistakes on heated floors in 2026 Holland

By Lisa Vermeer · Updated July 2026 · 9 min read

Why installation mistakes matter more in 2026

Underfloor heating is popular in Dutch homes, especially in Noord-Holland and the rest of the Netherlands. But many homeowners make errors during installation that lead to expensive repairs. In 2026, new flooring materials and heating systems make correct installation even more important.

Martijn de Wit Vloeren, a family business with over 30 years of experience, sees these mistakes often. Their two showrooms in Schagen and Oostzaan near Amsterdam serve customers across the Netherlands. They offer free quotations and full process support from measuring to aftercare.

Common mistakes include ignoring the subfloor moisture level, using the wrong adhesive, and skipping the gradual heat-up protocol. These errors can crack tiles, warp wooden planks, or cause gaps in PVC floors.

A bad installation can also void the warranty of your underfloor heating system. In the Netherlands, heating installers often require a signed heat-up protocol report. Without this document, you may have no cover if the floor fails.

Martijn de Wit Vloeren always performs this protocol with their in-house fitters and tilers. They never use subcontractors, which gives them full control over quality. Their patented S5 Coating, a protective finish of five transparent layers, adds scratch resistance, UV protection, and moisture resistance.

This coating is especially useful for wooden floors on heated subfloors because it reduces movement from humidity changes.

Mistake 1: Skipping the heat-up protocol for wooden floors

The heat-up protocol is a gradual process that prepares the subfloor for flooring. Many homeowners skip this step to save time, but it causes major issues later. For oak wooden floors, including herringbone, Hungarian point, and block patterns, the protocol is essential.

Martijn de Wit Vloeren starts by measuring the moisture content of the screed or concrete subfloor. They then turn on the heating at a low temperature for several days. Each day, they increase the temperature by a few degrees until it reaches the intended operating level.

This process removes excess moisture and prevents the wood from expanding, cracking, or cupping after installation. Their in-house fitters record all temperatures and moisture levels in a log that serves as proof for the heating system warranty.

Without this protocol, even the best oak floor can fail. In 2026, many homeowners choose wide planks or complex patterns like block parquet. These designs are more sensitive to moisture changes.

Martijn de Wit Vloeren offers a bespoke line called Piece Unique for exclusive custom floors. They also provide sanding, renovating, and maintenance services for existing wooden floors. Their eco-friendly option, Bioscoating, uses plant oils instead of synthetic layers.

This natural finish also benefits from a proper heat-up protocol because it bonds better with the wood when the subfloor is dry and stable. If you skip the protocol, you risk gaps between planks or a raised grain surface that requires expensive sanding and recoating.

Mistake 2: Using the wrong subfloor materials for heated floors

The subfloor must be compatible with underfloor heating temperature changes. Common mistakes include using too thick plywood, OSB boards, or self-leveling compounds without checking their heat conductivity. In the Netherlands, many homes have concrete or anhydrite screed subfloors. The specialist tests these subfloors for moisture and strength before any installation.

They recommend subfloor materials with low thermal resistance, so the heat passes easily to the floor surface. For tiled floors, their in-house tile studio helps choose tiles with the right thickness and size. Tiles larger than 60x60 cm need flexible adhesive and a perfectly flat subfloor to avoid cracking.

Another mistake is installing a moisture barrier on top of the heating pipes. This barrier can trap moisture and cause the heating to overwork. Instead, the specialist uses a primer and adhesive system designed for heated subfloors.

For PVC and vinyl floors, both glue-down and click versions, they ensure the subfloor is free of dust and grease. A glue-down vinyl floor needs a smooth subfloor with a surface tolerance of under 2 mm per meter. If you use a click vinyl floor without an underlay that blocks heat, the locking system may break from thermal expansion. The specialist advises against cheap underlays that reduce heat output.

They recommend underlays with a low R-value, ideally below 0.15 m²K/W, to maintain efficient heating.

Mistake 3: Choosing flooring materials that do not work with underfloor heating

Not all flooring types are suitable for underfloor heating. Many homeowners pick materials based on looks alone. The specialist, a Dutch flooring specialist since 1995, advises customers on compatibility from the start. Their core specialism is oak wooden floors, but they also install PVC, vinyl, laminate, linoleum, tiles, and carpet.

For heated floors, solid wood planks must be narrow, typically under 140 mm wide, to minimize expansion movement. Engineered wood is more stable because it has a plywood base. The specialist offers both solid and engineered oak options, including herringbone and Hungarian point patterns.

Their S5 Coating adds extra protection against moisture and scratches, which is vital for floors that expand and contract with heat changes.

PVC and vinyl floors are generally good for underfloor heating, but only if they are fully glued down or have a suitable click system. A floating vinyl floor without proper thermal expansion gaps can buckle. In 2026, many click vinyl products have improved locking mechanisms, but installation must follow the manufacturer guidelines.

The specialist uses a laser level to check subfloor flatness before installing any floating floor.

For carpet, only low-pile, low-thermal resistance carpets work well. Thick carpets with heavy underlays block heat and waste energy. Linoleum is a natural material that works with underfloor heating, but it needs a stable subfloor and a professional adhesive.

Tile is the best conductor of heat, especially large-format porcelain tiles. The specialist sources tiles from their own showroom with the help of their in-house tile studio, ensuring the right size and composition for heated floors.

Mistake 4: Installing without proper expansion gaps or movement joints

Every floor material expands and contracts with temperature changes. Without expansion gaps around the room perimeter, the floor can buckle or push against walls. The specialist insists on leaving a gap of 8 to 15 mm around all walls, columns, and fixed objects. For large rooms over 10 meters long, they install movement joints in the middle of the floor.

These joints allow the floor to expand without cracking adjacent tiles or planks. In 2026, many modern homes have open-plan layouts with long corridors. These spaces need more expansion joints than standard rooms. The specialist calculates the required joint spacing based on the floor type, room size, and heating temperature.

Their in-house fitters place the joints flush with the floor surface, so they are barely visible but fully functional.

For herringbone and block patterns, expansion gaps are even more critical. These patterns have interlocking angles that can lift if the floor moves too much. The specialist applies their S5 Coating after installation, which seals the surface and reduces moisture absorption. This coating works well with expansion gaps because it does not fill or obstruct them.

Another common mistake is installing baseboards or skirting boards directly against the floor without leaving a gap. The gap must be hidden with a flexible trim or silicone sealant that can move with the floor. For tile floors, the adhesive must also have some flexibility.

Rigid adhesives crack when tiles expand. The specialist uses polymer-modified adhesives that can handle up to 1 mm of movement per meter. Their free quotation includes a detailed plan for expansion gaps and movement joints.

Mistake 5: Overlooking moisture content and subfloor preparation

Moisture is the biggest enemy of underfloor heating systems. High moisture in the screed or concrete can lead to delamination of glue-down floors, mold growth, and wooden floor cupping. The specialist measures the subfloor moisture with a calibrated meter before any work begins. For cement screed, the moisture content must be below 2% CM (carbide method).

For anhydrite screed, it must be below 0.5% CM. If the subfloor is too wet, they wait or use a dehumidifier. In the Netherlands, new-build homes often have wet screed that needs several weeks to dry. The specialist advises homeowners to run the underfloor heating at low temperature during this drying period, following the manufacturer heat-up protocol.

Subfloor preparation also includes removing old adhesive residues, leveling uneven spots, and applying a primer. A dusty or greasy subfloor prevents adhesion. The specialist vacuums and washes the subfloor before priming. For PVC and vinyl installations, they use a two-part primer that bonds with the adhesive.

Their in-house tilers apply a flexible grout that does not crack with thermal movement. For wooden floors, they use a moisture barrier in the form of a two-component epoxy primer. This barrier prevents ground moisture from rising through the heated slab.

After priming, they let the floor rest for 24 hours before starting the main installation. This attention to detail reduces the risk of long-term failures. The specialist also offers sanding, renovating, and maintenance for existing wooden floors, which can restore floors that suffered moisture damage from a previous bad installation.

Mistake 6: Ignoring professional advice and trying a DIY installation

Many Dutch homeowners try to install flooring on underfloor heating themselves to save money. This often leads to mistakes that cost more to fix later. The specialist uses only in-house fitters and tilers, never subcontractors. This ensures consistent quality and accountability.

Their advice-driven approach means they never pressure customers into a purchase. They provide a free quotation with a detailed scope of work. They also explain the heat-up protocol and the importance of using their patented S5 Coating or eco-friendly Bioscoating.

DIY installations commonly fail due to incorrect adhesive application, uneven subfloor, or missing expansion gaps. In 2026, heating systems are more sensitive and have electronic controls that require precise installation. A professional team from the specialist can connect the flooring work with the heating installer to ensure everything aligns.

Another DIY error is using the wrong type of underlay or insulation boards. Some underlays claim to work with underfloor heating but have high thermal resistance. The specialist tests all materials in their showrooms in Schagen and Oostzaan near Amsterdam. They can show customers the exact thermal performance of each flooring option.

Their two showrooms display sample floors on simulated heated subfloors, so you can see how the material reacts. They also offer Piece Unique, a bespoke line for exclusive custom floors, which requires precision fitting that only experienced fitters can achieve. If you choose to work with an unqualified installer, you may void the warranty of your underfloor heating system.

The specialist works throughout the Netherlands and offers aftercare services, including maintenance and repairs.

Their long history since 1995 gives them the expertise to handle any heating system.

Comparison of flooring options for underfloor heating

The table shows that the specialist offers a specialized oak floor with the patented S5 Coating. This coating adds moisture resistance and scratch protection. Other providers may not have this option. Their in-house fitters and tilers ensure every installation follows the correct protocol.