ᐅ Bathroom after complete renovation shows high humidity levels

Created on: 23 Sep 2021 22:20
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Deraggi2
D
Deraggi2
23 Sep 2021 22:20
Hello,

we have completely renovated a house and are generally satisfied. However, we have noticed that our bathroom on the ground floor has a high humidity level. My smart radiator thermostat shows about 70%. The other rooms are not affected.

The bathroom has a shower, and the window is opened while showering. Even after 24 hours, there is still moisture noticeable in the bathroom. Additionally, there is a slight chemical smell that I unfortunately cannot identify.

There is nothing visible on the tiles or the window.

The following work was done, probably in June/July:
- Walls were opened, pipes rerouted, walls closed and plastered
- Floor removed, new screed applied
- Window in external wall replaced, smaller window therefore partially bricked up and plastered
- Tiled again

Does anyone have any idea how I should best proceed to find the cause?

Thank you in advance!
K
konibar
23 Sep 2021 23:09
The answers are always the same:

What is the relative humidity if no one has showered for about a week?

Get a capacitive moisture meter and check the walls/floors.
There might be a leak in a pipe inside the wall?!
D
Deraggi2
24 Sep 2021 07:46
Hello, first of all thank you very much for your help. The ideas are very good and we will try them out. So, I would not shower in this bathroom for a week, of course still ventilating properly, and then see if the humidity rises again.

In addition, I will get a moisture meter. I really hope that we don’t have a leak...
I
Interrupt
24 Sep 2021 12:03
If the issue is only in the bathroom, this also suggests a local cause. Checking the walls is certainly a good idea. But just to be sure:
  • The list of works refers to the entire house, not just the bathroom, correct?
  • Which screed was used? Cement, anhydrite, calcium sulfate, or something else? With or without drying accelerators?
  • Thickness of the screed layer?
  • Was underfloor heating installed and was the screed heated?
  • What measures did you take for drying after plastering and laying the screed?
  • How much time did you allow the screed to dry before tiling?