Can You Install Underfloor Heating Under Vinyl Flooring?
Yes. Electric underfloor heating can be installed beneath many types of vinyl plank, luxury vinyl tile and sheet vinyl flooring, provided the heating system and floor build up are designed correctly.
Vinyl flooring is popular throughout Australian homes because it is durable, easy to maintain and available in a wide range of timber, stone and contemporary finishes. Combining vinyl flooring with electric underfloor heating can add another level of comfort, particularly in kitchens, living areas, laundries and other spaces where cold floors can be noticeable during winter.
However, vinyl is sensitive to excessive temperatures and movement. For that reason, installing underfloor heating beneath vinyl requires careful attention to the substrate, heating cable installation, self-levelling compound and thermostat controls.
At Demarc Climate Solutions, we recommend looking at the complete floor construction before installation begins rather than treating the heating system as a standalone component.
Installing Underfloor Heating Over a Timber or Hardwood Subfloor
A common question is whether electric underfloor heating can be installed over an existing timber or hardwood floor before new vinyl planks are laid.
In many cases, the answer is yes.
The important consideration is that timber naturally expands and contracts in response to changes in temperature and moisture. When underfloor heating is added, repeated heating and cooling cycles can contribute to movement within the floor structure.
For this reason, the heating system should generally not be installed directly over an existing hardwood subfloor without a suitable intermediate layer.
Standard hardboard is not normally the preferred substrate in this application. Instead, a dimensionally stable and heat-resistant flooring board should be installed over the existing timber.
Depending on the project, suitable options may include:
- a minimum 6 mm fibre cement underlay; or
- a cement coated thermal insulation board such as a Marmox style board.
This creates a secure and stable surface for the electric heating system while helping isolate the finished vinyl flooring from movement in the timber floor below.
A thermal insulation board can also help reduce downward heat loss and encourage more of the heat generated by the system to travel upwards into the floor surface and room.
A Typical Floor Build-Up for Vinyl and Underfloor Heating
For an installation over an existing timber or hardwood subfloor, a typical floor build-up may look like this:
Existing timber or hardwood subfloor → fibre cement or thermal insulation board → thin electric heating cable mat → self-levelling compound → vinyl plank or sheet flooring
The exact products and thicknesses required will depend on the condition of the existing floor, the heating system being installed and the requirements of the vinyl flooring manufacturer.
The key objective is to create a stable, smooth and heat-compatible surface beneath the vinyl.
Installing a Thin Electric Heating Cable Mat
Once the correct substrate board has been installed, a low profile electric underfloor heating system can be fitted.
Amuheat’s Thin Cable Mat system is particularly well suited to renovation projects because it minimises the additional height added to the floor.
The thin cable heating systems use a low profile heating cable that can be secured directly to the prepared substrate.
The cable layout should always follow the heating manufacturer’s installation requirements. Heating cables must not cross or overlap, and the heating layout should be planned around permanent fixtures and areas where heat could potentially become trapped.
The electrical requirements should also be considered during the planning stage.
Knowing the total number of square metres to be heated allows the correct heating system size, electrical loading and thermostat requirements to be established before installation begins.
Why Self-Levelling Compound Is Important
When installing electric underfloor heating beneath vinyl, the heating cable should be fully encapsulated in a compatible self-levelling compound.
The self-levelling screed performs several important functions.
Firstly, it protects and surrounds the electric heating cables.
Secondly, it produces the flat and consistent surface required for vinyl flooring installation.
It also helps distribute heat evenly across the finished floor rather than allowing concentrated heat directly above individual heating cables.
The self-levelling compound must be installed at the minimum depth specified by its manufacturer. Applying the product too thinly can increase the risk of cracking as the floor experiences normal movement and ongoing heating and cooling cycles.
The levelling compound must also be allowed to cure fully before the vinyl flooring is installed or the heating system is commissioned.
Choosing Vinyl Flooring Suitable for Underfloor Heating
Not every vinyl flooring product has exactly the same requirements.
Before installing electric underfloor heating, confirm with your vinyl flooring supplier that the selected flooring is suitable for use over underfloor heating.
This applies to:
- vinyl plank flooring;
- luxury vinyl tile or LVT;
- sheet vinyl;
- glue down vinyl; and
- compatible floating or click lock vinyl products.
The flooring manufacturer may specify particular adhesives, underlays, installation methods or maximum operating temperatures.
Any adhesive or fixing product used with the vinyl should also be approved for the temperature changes associated with underfloor heating.
Following the vinyl manufacturer’s instructions is particularly important where maintaining the flooring warranty is concerned.
What Temperature Can Vinyl Flooring Handle?
Temperature control is one of the most important factors when using electric underfloor heating under vinyl flooring.
Many vinyl manufacturers specify a maximum floor surface temperature of approximately 27°C.
However, this limit should always be confirmed with the manufacturer of the specific vinyl flooring being installed.
A suitable underfloor heating thermostat should include a floor temperature sensor or floor probe.
The probe is installed within the heated floor and allows the thermostat to monitor and limit the actual floor temperature.
This is important because controlling room air temperature alone does not necessarily prevent the floor itself from reaching a higher temperature.
For vinyl flooring applications, the thermostat can be configured so the floor temperature remains within the flooring manufacturer’s permitted operating range.
Demarc offers thermostat options including programmable touch-screen and Wi-Fi enabled controls, allowing the heating system to be operated conveniently while maintaining the required floor temperature limits.
Gradually Warm the Floor After Installation
Once the vinyl flooring has been installed, the underfloor heating system should not immediately be operated at full temperature.
All flooring adhesives, levelling compounds and other installation products should first be allowed to cure for the period specified by their manufacturers.
The heating can then be introduced gradually.
Slowly increasing the floor temperature allows the finished vinyl and surrounding materials to acclimatise to the heating system and reduces unnecessary thermal stress.
Always follow the commissioning requirements provided by both the heating and flooring manufacturers.
Planning Electric Underfloor Heating for Vinyl Flooring
Good planning is the key to a successful underfloor heating installation.
Before starting, consider the complete flooring system, including:
- the existing subfloor;
- fibre cement or thermal insulation board;
- electric heating mat;
- self-levelling compound;
- vinyl flooring and adhesive;
- thermostat and floor sensor;
- electrical conduit requirements; and
- total heated floor area.
If you are planning to install electric underfloor heating under vinyl plank or sheet flooring, Demarc can assist with system selection, electrical loading information and heating layout requirements.
To obtain pricing or determine the correct heating system for your project, send us a floor plan showing the area to be heated or provide the approximate square metre area of the floor.
With the correct substrate preparation, temperature controls and installation method, electric underfloor heating can provide comfortable, efficient floor heating beneath vinyl without compromising the finished flooring.