In order to seal my shower enclosure, I would like to stick PVC sheets (h = 2m, l = 0,80m, thickness = 2mm) on the faulty earthenware. Could you tell me what glue to use (references) and how to do it?
The solution you mention seems difficult to achieve and the result is likely to be very disappointing. If your support is saturated with humidity, it is because the wall is impregnated with water. By sticking this type of coating, you risk trapping this moisture and further degrade the masonry.
If the faience is not too degraded, you can pass a transparent resin after complete drying of the support with a dehumidifier. You can also seal the joints with clear varnish. But the best solution would be to deposit the faience, let the wall completely dry and then redo it. This will avoid many problems of infiltration.
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