Wunda Rapid Response® Floor Coverings Information

Wood Floor Coverings

Wood can be used with underfloor heating, but it's a natural insulator, so heat spread is less efficient than with natural conductors. Maple and beech woods are not suitable. Always check with your flooring supplier for suitability and thermal resistance. The total thermal resistance of the chosen wood should be less than 2.5 Tog (0.25 m²K/W). Engineered wood is often preferable due to its stability.

Installation Methods:

1. Free floating: Use a suitable underlay (e.g., Wunda 3mm breathable XPS underlay with R value of approx. 0.056m²K/W).
2. Bond direct: Use approved high-temperature wood adhesive (e.g., Mapei Ultrabond Eco S955 1K).
3. Self-levelling compound: Apply an approved self-levelling compound over the Rapid Response panels. Floor probes must be installed at the uppermost surface.

Preparation:

Acclimatise wood before installation. Use a room sensor/thermostat with a floor probe set to cut out heating at 27°C floor surface temperature.

Curing and Activation:

Allow adhesives and levelling compounds to cure naturally. Gradually increase heating temperature by 5°C per day.

Floor Probe:

The floor probe protects flooring from overheating by cutting off flow if it gets too warm. It needs to be in contact with the floor finish. For self-levelling compounds, place the probe on top after curing, potentially in a chased channel.

Laminate Floor Coverings

Laminate is a popular, affordable, and durable flooring option that works well with underfloor heating. Check with your supplier for suitability and any floor surface temperature limitations (often 27°C). A floor probe is recommended.

Installation Methods:

1. Free floating: Use a suitable underlay (e.g., Wunda 3mm breathable XPS underlay with R value of approx. 0.056m²K/W).
2. Self-levelling compound: Use an approved levelling compound as an intermediate layer, especially for intricate patterns like herringbone.

Preparation:

Acclimatise laminate before installation. Use a room sensor/thermostat with a floor probe set to cut out heating at 27°C floor surface temperature.

Curing and Activation:

Allow levelling compounds to cure naturally. Gradually increase heating temperature by 5°C per day.

Floor Probe:

Laminate floors can be temperature sensitive. A floor probe is required to cut out heating if surface temperatures reach 27°C. Ensure the probe is in contact with the floor finish.

Carpet Floor Coverings

Carpets and rugs can be used with underfloor heating, but their insulating properties can affect heat transfer. The combined tog rating of the carpet, underlay, and any intermediate layers should not exceed 2.5 tog. Always check with your supplier for suitability.

Installation Methods:

1. Duo board: Use Wunda Duo board (7mm total depth, 0.5 tog thermal resistance) as an intermediate layer. Carpet and underlay should have a combined tog of 2 or less. Duo board is not suitable for wet areas. Install in a staggered brick bond format with an 8-10mm expansion gap around the perimeter.
2. Self-levelling compound: Use an approved levelling compound as an intermediate layer for a smooth surface.

Preparation:

Install battens around the room perimeter and across door thresholds for fixing gripper rods and door bars.

Curing and Activation:

Allow levelling compounds to cure naturally. Gradually increase heating temperature by 5°C per day.

LVT and Vinyl Floor Coverings

LVT and vinyl flooring are popular and work well with Wunda underfloor heating. Some LVT/vinyl requires a maximum floor temperature of 27°C, managed by a floor probe. If using LVT, ensure manifold flow temperature does not exceed 45°C.

Installation Method:

Self-levelling compound: LVT requires a smooth, level, and firm surface. Use an approved self-levelling compound or renovation screed. Perimeter strip is necessary for expansion.

Preparation:

Acclimatise floor finish before installation. Use a room sensor/thermostat with a floor probe set to cut out heating at 27°C floor surface temperature.

Curing and Activation:

Allow levelling compounds to cure naturally. Gradually increase heating temperature by 5°C per day.

Floor Probe:

LVT and vinyl are temperature sensitive. A floor probe is required to cut out heating if surface temperatures reach 27°C. Ensure the probe is in contact with the floor finish.

Installation Process:

Incorporate an expansion gap around the perimeter. Ensure floor finish runs 90° perpendicular to pipe runs if possible.

Turning on Heating:

Keep floor at ambient temperature with heating off for 7 days post-installation. Then, gradually increase flow temperature by 5°C per day.

Poured Floor Coverings

Poured finishes like micro-cement, polished cement, resin, and terrazzo are good conductors of heat and work well with underfloor heating.

Installation Method:

Self-levelling compound: A poured floor finish requires a smooth, level, and firm surface. Use an approved self-levelling compound or renovation screed. Perimeter strip is necessary for expansion.

Preparation:

Ensure Rapid Response boards are securely bonded and there is no movement. Cut aluminium of unused pipe channels to expose them for filling with levelling compound.

Curing and Activation:

Allow adhesives and levelling compounds/screeds to cure naturally. Gradually increase heating temperature by 5°C per day.

Tile and Stone Floor Coverings

Tile and stone floors are natural conductors and work well with underfloor heating. Thicker finishes will result in longer warm-up and cool-down times. Consider thinner natural stone for faster response.

Installation Methods:

• Small form factor tiles (10cm x 10cm): Requires an approved self-levelling compound prior to tiling for a level surface.
• Ceramic and porcelain tiles: Can be fixed directly to panels. For easier removal in the future, consider a levelling compound first.
• Natural Stone: Can be bonded directly with approved adhesives (e.g., Ultra ProFlex S2 with Prime IT primer) or with a levelling compound as an intermediate layer. Some adhesives (e.g., Mapei Kerabond T & Isolastic) require a levelling compound intermediate layer and cannot bond directly.

When tiling direct:

Perimeter strip is necessary for expansion.

Recommended adhesives:

• Mapei, Kerabond T & Isolastic (100:33 ratio): Deformable, slow-setting. No primer needed for direct tiling.
• Ultra ProFlex S2: Deformable, fast-setting. Boards and pipes need priming with Prime IT multi surface primer.

When using a self-levelling compound intermediate layer:

Use an approved levelling compound for a smooth surface, with perimeter strip for expansion. After curing, use an approved tile adhesive.

Ditra matt & decoupling membranes:

Can be used for tiling. Tile adhesive is used to fix the membrane and then the tiles.

Grout:

Any flexible grout can be used.