What thickness of insulation for underfloor heating?

To reduce heat loss in your home, insulating your floor to the ground could be a good place to start. Nevertheless, it is not always easy to choose the right thickness for the insulation of this device. In this article, we help you decide.

What are the criteria to consider when choosing the thickness of the insulation?

For optimal heating of the floor of your home, the choice of the thickness of the insulation is an essential parameter. It is through the latter that the device will be able to best distribute the heat. Nevertheless, for the choice of the heating device, several parameters must be considered.

The type of insulation

The type of underfloor heating

Basically, there are two types of underfloor heating: electric underfloor heating and hydraulic underfloor heating.

The first is a device consisting of a heating cable that is very easy to install. It can be adapted to any type of housing.

The second is made up of pipes through which hot water is circulated. Unlike underfloor heating, electric, this type of system cannot be adapted to all types of housing.

In addition, it requires a fairly large floor space.

The type of insulation

In addition to the type of floor, the nature of the insulation will also have a significant impact on the thickness to choose. Note that there is an anthology of insulation on the market suitable for various heating systems among which you can find the one that suits you. Among other things, you have Polystyrene PSE known for its high resistance and good thermal conductivity.

There is also rock wool used by many professionals although it is not the first insulator that comes to mind for underfloor heating. You also have XPS extruded polystyrene with its attractive thickness and affordable cost. It is also lightweight and offers very good insulation performance. Finally, you have PUR polyurethane which is perfectly resistant to humidity.

Installation technique and thermal resistance

There are two techniques for laying thermal insulation. The first is to install it from below the house while the second is to go from above. The first is quite simple to make and allows you to keep a good part of the living space. The second is a little more complex to install and requires more requirements in terms of the thickness of the insulation.

Also, you have the thermal resistance which is an important parameter for the good diffusion of heat and for your comfort. You should know that with good thermal resistance, you will not need too thick insulation.

Which thickness to choose for your underfloor heating insulation

What thickness should you choose for your underfloor heating insulation?

To give you an idea of ​​the choices to be made for the thickness of your underfloor heating, remember that for a floor heated from below with polystyrene, you need a thickness between 90 and 120 mm while you need between 70 and 100 mm if polyurethane is used. On the other hand, if the heating is carried out from above, the thickness can vary between 60 and 70 mm if it is made with polystyrene.

Moreover, for a floor heated with an electrical device, if you have insulation with a thermal resistance of more than 2.50 m².K/W, you need a minimum thickness of 55 mm. However, when using water-based underfloor heating, the values ​​vary. In other words, it is important to seek the help of your professional to have a fairer and safer opinion when choosing the thickness of your insulation.

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