POTENTIAL CAUSES OF THE PROBLEM

a) Possible entrapped moisture content on substrate
b) Varnish was applied too early, entrapping moisture in substrate
c) Bad choice of varnish (water varnish chosen in wet areas instead of polyurethane varnish)
d) Bad application of varnish

SOLUTION

1: Surface rubbing with an electric sander in order to remove varnish
2: Leave surface as long as it is needed for moisture to be evaporated
3: Apply GLX 292 FLEX PRIM
4: Apply DECOR PU VARNISH (mat or gloss) in two coats. Second coating applied after first one is dried.

In case of upcoming moisture to remove polished cement screed and proceed to waterproofing substrate with DSF 353 SUPER ELASTIC before application of DECOR.