Are you going to install underfloor heating? Then you probably have many questions about the floor construction for underfloor heating, the possible materials, and much more. That’s why we’ve listed the key points for you. This way, installing underfloor heating becomes almost child’s play!
Underfloor heating under every floor
We can already reassure you: in principle, you can install underfloor heating under any type of floor. Laminate, parquet, vinyl, and high pressure floors — they are all suitable. So you can simply choose your favorite flooring material!
Glue or not? You can install underfloor heating under both a glued and a floating floor. With a floating floor, there is an extra air layer, which means the heat passes through just a little less quickly. A glued floor is therefore slightly more energy efficient.
Laminate - Ocean+ - Select Light Brown
Floor construction for underfloor heating
Whichever type of floor you choose: correct installation of underfloor heating is always crucial. Our floor experts recommend that you always take the following points into account:
1. Work clean and dry
Installing a floor with underfloor heating should be done on a clean, dry, flat, and hard subfloor. Otherwise, you’ll get unevenness and/or moisture problems.
2. Turn off the heating for a while
Of course, first and foremost, your screed must be completely dry, which can take one to several weeks. But before you place the floor on the underfloor heating, it’s also important to switch off the underfloor heating for a few days. Then let the room warm up gradually — not immediately on the hottest setting. This way, you avoid problems in the floor surface caused by large temperature differences.
3. Ensure a controlled environment
During the installation of the floor, monitor the temperature and humidity in the room. Ideally, a temperature of 18 to a maximum of 20°C and a humidity level of 40 to 60 percent.
4. Place a vapor barrier
A vapor barrier is a waterproof foil that prevents water vapor or condensation from the subfloor from damaging the installed floor. It’s best to place a vapor barrier of at least 0.2 mm thick, or choose an underlay with integrated foil such as Excellence Plus.
5. Insulate well
To minimize heat loss, place an insulating layer under your underfloor heating of at least 5 cm, but you can even go up to 15 cm. A floor with underfloor heating requires a thicker insulation than a floor without underfloor heating.
Tip:
Be sure to check whether you are eligible for a government grant for your floor insulation.
6. Watch out for expansion joints
Regardless of the type of floor, with a floating installation you must provide enough expansion joints so that the flooring material has room to “move.” Due to temperature differences, your floor can expand and contract. Without expansion joints, you risk a floor that doesn’t stay flat, or other problems.
7. Heating capacity
For an electric heating system, a maximum capacity of 18 watts per meter of cable or 60 watts per m² is recommended.
8. Avoid large rugs
A rug feels wonderfully soft under your feet, we understand that. But if you choose underfloor heating, it’s not a good idea to cover a large area with a rug. That prevents the heat from passing through properly, resulting in a higher energy bill and possibly problems with your floor.
Surface temperature of your floor
In addition, for parquet as well as other floor types, you must check the surface temperature. Your floor should not get warmer than 27 to 28°C. Do you have a water-based heating system? Then your supplier must calculate the maximum incoming and outgoing water temperatures so that the surface temperature does not exceed that level.
Thermal resistance of your floor
The cumulative thermal resistance of the floor also matters: the thermal resistance of the vapor barrier plus the underlay or subfloor plus the floor itself. When you add this up, according to the European standard (NF EN 12667), it may not exceed 0.15 m² k/W.
Laminate - Ocean+ - Gyant Natural
What about cooling?
Nowadays, there are systems that combine underfloor heating and floor cooling. Handy on hot summer days. But floor cooling does carry a risk for your floor.If the temperature of the cooling water drops to the so-called dew point, this causes condensation, which can lead to various issues: mold with vinyl, swelling with wood (laminate and parquet), etc.
Are you installing a cooling system under your floor? Then pay attention to this:
- Never let the water temperature in your heating/cooling system drop below 18°C.
- Make sure the temperature difference between the floor and the room is never more than 6°C. A floor of 20°C in a room where it’s 30°C? Not a good idea.
- Choose a cooling system with an anti-condensation control system. This automatically regulates the temperature of the incoming water.
- Double-check with the supplier of your underfloor heating/cooling system whether it is compatible with the specific laminate floor you plan to install.
