Approved membranes, wall-adjacent drains and wet-room boards

Under GVK, you can't just waterproof with "something that looks waterproof." Only industry-approved products may be used, and they must be installed as complete, matched systems per the supplier's documented instructions. That single rule removes a huge share of failures.

The approved membrane families

GVK recognises several categories of tätskikt (waterproof layer), all of which must be industry-approved:

• Plastic (vinyl) mat — used both as the sealing layer and finished surface, or as a sealing layer beneath ceramic tiles.
• Sealing-foil systems — sheet membranes bonded to the substrate.
• Liquid-applied systems — built up in coats to a controlled film.
• Tight-board systems — approved waterproof boards.

Each is a *system* — membrane, collars, adhesives and boards from a compatible, approved kit. Where two different membrane types meet, at least one responsible supplier must provide a written mounting instruction for that specific combination.

Wall-adjacent drains and wet-room boards

A wall-adjacent floor drain (väggnära golvbrunn) — one set closer than 200 mm to a wall — must be approved for near-wall placement *together with the specific waterproofing system* it's used with. Only proven drain-and-membrane combinations may be paired. Wet-room boards (våtrumsskivor) must likewise be approved, and adhesives on plastic mat matched to the system.

The vapour-resistance rule

A membrane installed under ceramic tiles must have a vapour-passage resistance exceeding one million s/m, unless a formal moisture-safety design says otherwise — so moisture can't accumulate behind the tiles.

What M5 brings to Dubai

We use only tested, approved systems, installed complete and matched — never a cheaper component slipped into a system it was never tested with. It's invisible in the finished room, and it's exactly where corners get cut elsewhere.

Official source: this is M5's plain-language summary, not the official text. For the full rules see GVK — gvk.se.