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Norway's Wet-Room Rules: TEK17 §13-15, a Real Statutory Clause

Norway is unusual — TEK17 §13-15 is an explicit statutory wet-room clause, not just a performance placeholder. It requires drained floor falls, directed leak water and sealed waterproofing, but the actual figures live in the private Våtromsnormen and SINTEF Byggforsk detail sheets.

TEK17 §13-15 Clause NO TEK17 §13-15

The requirement

TEK17 §13-15 is Norway’s wet-room clause. It asks for three things. The floor must fall to the drain. Leak water must be led to a spot you can see. Weak surfaces must be waterproofed, with every hole sealed. The clause gives no figures. Those sit in Våtromsnormen and the SINTEF Byggforsk 520-series.

Norway stands out here. The wet room gets its own named clause in the building law itself. The UK’s Approved Document C says nothing about wet rooms. Ireland’s TGD C is silent too. Norway’s clause is TEK17 §13-15, “Våtrom og rom med vanninstallasjoner” (Wet rooms and rooms with water installations). It sits in the Byggteknisk forskrift, the national building regulation. DiBK (Direktoratet for byggkvalitet) runs that regulation. DiBK also attaches guidance (veiledning) to §13-15. The guidance spells out what the clause covers. It stops short of giving a number.

What §13-15 requires:

  • Drained floor falls. The floor must fall toward the floor drain (sluk). Not flat. Not falling toward a doorway, or a wall away from the drain.
  • Leak water led to a visible drain. A pipe joint or seal can fail over time. Water that gets past the waterproofing must be led where it can be seen. It must not sit trapped in a wall or floor build-up. Trapped water breeds rot and mould you never see.
  • Waterproofing of moisture-vulnerable substrates, with sealed penetrations. Surfaces that cannot take ongoing moisture must be waterproofed. That means timber-based flooring, gypsum-based wall linings and the like. Every hole through the waterproofing must be sealed as part of the system. That covers pipes, mixer bodies and waste outlets.

These are real, binding rules. They are not loose goals. But §13-15 and its veiledning fix no shower-wall height. No minimum floor-fall gradient. No membrane-overlap size. Australia’s NCC prints those numbers in its code. Norway’s code does not. The numbers live one layer down, in industry standards.

Where the actual figures live

Våtromsnormen (the Wet Room Standard) holds the buildable numbers. Fagrådet for våtrom (FFV) publishes it. It is a private industry standard. Trades and designers use it to turn §13-15 into floor falls, membrane overlaps and upstand heights. SINTEF Byggforsk holds the drawings. Its Byggforskserien 520-series detail sheets are the wet-room reference the industry builds from.

Both are paid, private publications. They are not part of the free statutory text at dibk.no. One caveat. We read DiBK’s guidance page for §13-15 for this article. That page does not itself cross-reference Byggforskserien. The link between them is settled industry practice all the same. Need it stated in writing? Ask FFV or SINTEF Byggforsk directly. This page prints no shower-wall height, floor-fall percentage or membrane-overlap figure. Those exact numbers sit inside the paid editions. We will not ship a number this page cannot stand behind.

On site — what this means for you

  1. Treat §13-15 as a real, binding clause. It is not a placeholder you meet with “reasonable effort”. Drained falls, led leak water and sealed, waterproofed substrates are the law.
  2. Get the figures from Våtromsnormen or the Byggforsk 520-series. Not from this page. Not from another country’s numbers. Norway’s own build-to detail lives in those publications.
  3. Seal every hole as part of the waterproofing, not after it. Sequence the trades so it happens that way. A tap or waste cut through a finished membrane, with no reseal, is the exact failure this clause targets.
  4. Send leak water somewhere visible. Detailing a wet-room floor build-up? Make sure any second drainage path ends where it can be seen and checked. Never hide it inside the structure.

Sources

  • TEK17 §13-15 (Våtrom og rom med vanninstallasjoner) — the statutory wet-room clause: drained floor falls, directed leak water, and sealed waterproofing of moisture-vulnerable substrates and penetrations. Read it at dibk.no.
  • Våtromsnormen, Fagrådet for våtrom (FFV) — the private industry standard carrying the dimensioned wet-room waterproofing detail; not reproduced on this page. See ffv.no (or FFV’s current domain) for access.
  • Byggforskserien, 520-series, SINTEF Byggforsk — construction-detail sheets for wet-room waterproofing, the practical industry reference alongside Våtromsnormen; also not reproduced here.

Read this first. TEK17 §13-15 is genuinely unusual among this cluster’s pages — a real, named, statutory wet-room clause, confirmed by direct read of DiBK’s own regulation text. But its qualitative requirements are only half the picture: the dimensioned detail a chippy actually builds to sits in the private Våtromsnormen and SINTEF Byggforsk 520-series, and this page deliberately ships no figure pulled secondhand from either. Confirm the current edition of both directly with FFV and SINTEF Byggforsk before relying on a specific number for a real job.

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