House made of sip panels. Walls gypsum fiberboard sheet 10mm in one layer on the metal frame.
Step 400 mm. Above it is the coating waterproofing. Ceramic tiles 500 by 300. Glue – K77.
Should I add another layer of fiberglass sheet, how critical is it that I have one layer? Grout is also supposed to be elastic, as well as the glue? Do I need an epoxy grout or can cement grout be elastic as well?