ᐅ Is it possible to apply waterproof slurry over paint? Or are there alternative options?

Hello,

we have moisture problems in an apartment caused by the exterior of the building. The neighboring building was demolished, leaving the exterior wall exposed to the weather. We also plan to work on this exterior wall. However, before that, we want to apply a waterproofing slurry on the interior surface, then insulate with Styrodur, and finally install a drywall system.

I have read that waterproofing slurry should not be applied over painted walls. Is this correct, and if so, what would be the alternative? Also, what do you think about using Styrodur insulation indoors? Unfortunately, the wall is very cold and does not really warm up during winter.

Thank you in advance.

Best regards

If the dew point cannot be calculated exactly, for example due to material-related issues, it might be worth considering having it calculated professionally. According to my rough estimate, it would most likely be located in a place where you wouldn’t want it. That doesn’t sound good to me.

Best regards
Gabriele