ᐅ Construction of Underfloor Heating, Screed, and Insulation Layers

Created on: 16 Mar 2016 07:58
C
Czantali
C
Czantali
16 Mar 2016 07:58
Hello,

We are planning to install underfloor heating on a concrete slab from 1969. The surface is quite rough, with some bumps caused by the stones in the concrete. I measured the height at various points using a laser level. The height difference ranges from 2.5 to 3 cm (1 to 1.2 inches), with 3 cm (1.2 inches) occurring within just 2 meters (6.5 feet) of distance. We want to keep the heating system’s buildup height as low as possible, as well as the costs 🙂.

The new electrical cables are installed in a conduit with a diameter of 16 mm (0.6 inches) on the concrete slab.

I am considering building the underfloor heating as follows: 2 mm (0.08 inches) of insulation, leaving space for the electric pipes, then 1.1 cm (0.43 inches) of insulation with a pipe carrier board, 17 mm (0.67 inches) pipes, and a 30 mm (1.2 inches) screed layer covering everything.

When I spoke with several screeders and plumbing installers, some recommended proceeding as planned, while others suggested first laying a leveling layer before the described buildup to prevent cracking in the screed. However, that would add about 3 cm (1.2 inches) in height, which would interfere with the door lintels.

What do you think?

Best regards

Czantali
C
Czantali
16 Mar 2016 19:59
Another opinion was to use soft expanded polystyrene (EPS) as the insulation layer, which would compress to accommodate uneven surfaces. Is that possible???