ᐅ Linear drain for level-entry shower with underfloor heating

Hello Yvonne

What concerns us the most is the issue of waterproofing, since we have an open kitchen directly below the bathroom.

Our heating technicians were especially considerate because we also have low-temperature underfloor heating. They installed the heating pipes in the shower as well, which is their usual practice.

Therefore, our question

Best regards and thank you for the answers

Underfloor heating can and should also be installed in the area of a walk-in (curbless) shower. To achieve a higher temperature in the bathroom, the heating pipes are laid more closely together. The installer should have a heating load calculation for each room, showing the length of underfloor heating pipe that needs to be installed in that room. In addition, there are thermostats.

Silicone joints are not waterproof. They are solely intended to bridge gaps between tiles, etc., and, if necessary, to accommodate different expansion behaviors of various materials.

The waterproofing of the floor and walls (in the shower area) is achieved exclusively through the waterproof membrane system, for example, Sakret FDS. This must be applied carefully. The required dry-layer thickness must be achieved, and it is advisable to verify this. Sealing tapes in and at the corners, as well as floor drains, must be properly integrated. All of this is detailed in the installation and application instructions provided by the manufacturers and in various technical data sheets that tile setters and installers MUST be familiar with.

We also have a tiled shower (actually two) with underfloor heating. Since we use geothermal energy for heating, underfloor heating makes a lot of sense.

Regarding warmth, I can say that the bathroom feels comfortably warm. Especially the warmth felt through the feet is pleasant. We have the thermostats in the bathrooms set to just 20°C or 22°C (68°F or 72°F).

As a layperson, I cannot say much about the construction itself. We had everything done by professional companies. However, one important point should be noted. The screed must be cement-based screed. If, for some reason, damage occurs and water reaches the screed, gypsum screed could swell. You can imagine the possible effects on tiles and so on. As far as I know, this does not happen with cement-based screed.

Furthermore, I can confirm what @Manu1976 mentioned: Water in the shower dries relatively fast when underfloor heating is present. I was and still am somewhat surprised by this. (Regardless of underfloor heating, it is advisable to squeegee the water after showering—this leads to faster drying and fewer stains.)

One general question: Is this thread not in the wrong section (building financing / mortgage)?

How do you properly clean the drain in a shower like this? So far, I’m only familiar with shower trays where you can place a strainer in the drain to catch hair and debris. How does it work with a linear drain?

f-pNo schrieb:
We had everything done by specialized contractors

I did the same. When remeasuring the thickness of the drying layer, the required value of 2 mm (0.08 inches) was not met. The crack-bridging capability of the waterproofing was insufficient. Rework was necessary.

Just because it says specialized contractor doesn’t mean it actually is. Monitoring the construction progress is essential, especially for critical areas like waterproofing.

f-pNo schrieb:
Cement screed must be installed. In case damage occurs and water reaches the screed, gypsum screed could swell. The effects this would have on tiles, etc. can be imagined. To my knowledge, this does not happen with cement screed.

I agree. Cement screed is the better choice in wet rooms.

klblb schrieb:


Not every company labeled as a specialist company actually is one. Monitoring the construction progress is essential, especially at critical points like waterproofing.

I agree with you. But if you
1. have no expertise in the subject and
2. are working away from 6:45 AM to 7:45 PM

you simply can't oversee everything.

However, we had what we considered a very competent and attentive site manager who closely monitored such details. In addition, a certified inspector from TÜV came five times to approve the various construction phases.

I hope everything went smoothly.