ᐅ Insulate underfloor heating on the ground floor or not?

Hello,

I have a question:

My house currently has an electric underfloor heating system installed on the ground floor, first floor, and attic in all rooms. I am planning to install a heat pump and retrofit water pipes by milling channels into the screed.

According to the building documentation, there is already insulation beneath the screed. Now I wonder if it makes sense to completely remove the screed on the ground floor, install new impact sound insulation and thermal insulation, and then lay a new screed. The terraced house was built in 1990.

For the first floor and attic, I plan to only mill the water pipes into the existing screed. Would you recommend also removing the screed on the ground floor, or is it sufficient there to just mill the pipes as well?

Best regards

If there is no information available about the floor structure, I would suggest opening up the floor at an inconspicuous spot to obtain the necessary details.

Knöpfchen schrieb:

If there is no information available about the floor structure, I would open the floor in an inconspicuous spot to obtain the necessary details.

The building permit / planning permission already states that there should be a 5 cm (2 inch) thermal and impact sound insulation layer. I assume it is there because I removed the tiles and you can see the edge insulation on the side.

But would that insulation be sufficient?

Knöpfchen schrieb:

Floor construction

You need to answer Knöpfchen’s question very specifically. Name each layer and the material used. For example, Styrofoam with a thermal conductivity rating (WLG) of 040 could be replaced by PUR with a WLG of 024.
If there is a 25mm (1 inch) cast asphalt screed, milling is not possible.
Just to mention two examples.

7 cm (3 inches) screed, vapor barrier, 5 cm (2 inches) thermal and impact sound insulation

Unfortunately, there are no details about the exact materials used, but the screed should be cement screed.

asaid10 schrieb:

7 cm (3 inches) screed, plastic sheet, 5 cm (2 inches) thermal and impact sound insulation

That’s what is specified there, but unfortunately I don’t have details on the exact materials used. However, the screed should be cement-based screed.

In that case, I would remove the screed, install a PUR (polyurethane) insulation layer, and then apply the thinnest possible screed over the underfloor heating pipes.
For example, 6 cm (2.5 inches) foil-faced PUR insulation, then tack a grid foil and the underfloor heating pipes on top. After that, pour a 60 mm (2.4 inches) screed layer (covering the pipes by 45 mm (1.75 inches)). This way, you reach your total of 12 cm (4.7 inches) thickness. This method roughly doubles your thermal insulation.