ᐅ Floor-to-ceiling tiled shower in new construction not properly sealed
Created on: 19 Sep 2025 09:22
J
Jschm88
Hello everyone,
In my newly built house from 2024, where we have been living for a year now, we installed the bathroom ourselves with the help of friends who are professionals (including a tile installer). We used very large format tiles.
Because of the walk-in shower without a shower tray, the shower area, as well as the entire bathroom, was waterproofed. Multiple layers of PCI Lastogum were applied, and of course sealing sleeves and waterproofing tapes were used at the transitions to the walls and in all corners. Underneath is a cement screed.
Recently, I happened to read that Lastogum is no longer approved for floors in such showers for a few years now. I have some questions about this:
1) Why was this changed? Were there any incidents? Why was this considered sufficient for decades before, but not anymore?
2) What about houses that were waterproofed the same way 8 years ago? Is there a reason to make corrections, or should nothing be done?
3) Specifically for me personally: should I consider opening up the floor, installing a waterproofing membrane afterwards, and then re-tiling? Or would that be excessive, considering it was only done a year ago?
4) Is there anything I should regularly check or monitor to detect major damage early?
Thank you all!
In my newly built house from 2024, where we have been living for a year now, we installed the bathroom ourselves with the help of friends who are professionals (including a tile installer). We used very large format tiles.
Because of the walk-in shower without a shower tray, the shower area, as well as the entire bathroom, was waterproofed. Multiple layers of PCI Lastogum were applied, and of course sealing sleeves and waterproofing tapes were used at the transitions to the walls and in all corners. Underneath is a cement screed.
Recently, I happened to read that Lastogum is no longer approved for floors in such showers for a few years now. I have some questions about this:
1) Why was this changed? Were there any incidents? Why was this considered sufficient for decades before, but not anymore?
2) What about houses that were waterproofed the same way 8 years ago? Is there a reason to make corrections, or should nothing be done?
3) Specifically for me personally: should I consider opening up the floor, installing a waterproofing membrane afterwards, and then re-tiling? Or would that be excessive, considering it was only done a year ago?
4) Is there anything I should regularly check or monitor to detect major damage early?
Thank you all!
W
wiltshire19 Sep 2025 10:28Jschm88 schrieb:
Based on the previous answers, the first step would be to relax, but it would still be interesting to find out why and what has changed there! I would also suggest relaxing.
Some countries have removed the material category "dispersion product" for surface treatment and generally require reactive or cementitious waterproofing products.
So, it's not about the specific product, but national regulations.
What I find disagreeable is the accusatory tone of the headline before gathering any information.
Thanks for the reassurance. I won’t take any action for now.
Just for next time – how could I improve the headline? I wanted it to be meaningful. That the waterproofing is not carried out correctly, at least in Germany and according to the latest DIN standards, is in my opinion correct and I was aware of this beforehand, as I was mainly asking about the reasons.
Just for next time – how could I improve the headline? I wanted it to be meaningful. That the waterproofing is not carried out correctly, at least in Germany and according to the latest DIN standards, is in my opinion correct and I was aware of this beforehand, as I was mainly asking about the reasons.