Waterproofing membrane

A waterproofing membrane is the continuous waterproof barrier applied to the concrete before the screed and tiles go on in any wet area — a bathroom, balcony, roof or water tank. This is the single most misunderstood detail in UAE homes: tiles, grout and silicone are the finish, not the waterproofing. Water passes through grout lines by design, and the membrane underneath is what stops it reaching the slab and the neighbour below. There are two families — liquid-applied (painted or rolled on, seamless, ideal for the fiddly corners and pipe penetrations of a bathroom) and sheet membranes (self-adhesive or torch-on bitumen, common on roofs and large decks). Almost every leak-to-the-flat-below traces to a membrane that was skipped, applied too thin, stopped short of an upstand at the walls, or punctured while the tiles went down — which is why a lasting fix means redoing the membrane, not just re-grouting. Getting it right is a job for a waterproofing specialist, and it always sits under the screed and finishes.