Poseidon Meets the US Tile Standards: ANSI A118.10 & A118.12
Poseidon Meets the US Tile Standards: ANSI A118.10 & A118.12
In an earlier post we looked at Poseidon's European Technical Assessment (ETA-23/0378) and what an ETA means for tilers and specifiers in the UK and Europe. But waterproofing standards do not stop at the Atlantic. In North America, tile installers work to a different — and equally demanding — set of benchmarks published by ANSI and tested to ASTM methods. Poseidon has been through those too. 💧
What the US standards mean
Two ANSI standards matter most for waterproofing behind tile:
- ANSI A118.10 covers load-bearing, bonded, waterproof membranes for thin-set tile installation. It is the benchmark a membrane must meet to be called waterproof in a US tiled assembly.
- ANSI A118.12 covers crack-isolation membranes — the ability to absorb minor substrate movement so cracks in the subfloor do not telegraph up and fracture the tile above.
Meeting one is good. Meeting both means a single product handles waterproofing and crack isolation in the same assembly — which is exactly what a US installer wants from a liquid-applied membrane.
Poseidon's US results
Testing was carried out at IPA Laboratories (a Tile Council of North America facility) in the USA. The headline figures:
ANSI A118.10 — waterproof membrane
- Breaking strength: 265 psi (requirement ≥170 psi).
- Seam strength: 20 lbf (requirement ≥16 lbf).
- Waterproofness: no moisture penetration.
- 7-day shear bond: 127 psi, and 7-day water-immersion shear: 109 psi (requirement >50 psi in each case).
- Does not support mould growth.
ANSI A118.12 — crack isolation
- Rated High Performance.
- Point load: 1,768–2,050 lbf (requirement >1,000 lbf).
In short, Poseidon comfortably clears the pass thresholds — often by a wide margin — for both the waterproofing and crack-isolation standards. 🛡️
Beyond ANSI: floor performance, vapour and air quality
US installers also look at how an assembly behaves underfoot and indoors. Poseidon has additional data here:
- ASTM C627 (Robinson floor test): Moderate — it passes cycles 1–10, confirming suitability for residential and light-commercial floor service.
- ASTM E96 (water-vapour transmission): approximately 0.25 perm, indicating a low-permeance membrane.
- California Section 01350 indoor-air test: TVOC 0.000 mg/m³ — effectively zero VOC emissions, which matters for enclosed bathrooms and any project chasing low-emission or green-building criteria.
Specifiable on both sides of the Atlantic
This is where Poseidon's position becomes genuinely unusual. The same membrane holds:
- A European Technical Assessment (ETA-23/0378) under EAD 030352-00-0503, with EN 14891 testing behind it.
- US compliance with ANSI A118.10 and A118.12, plus ASTM C627, ASTM E96 and CA 01350 data.
For a contractor or specifier working across markets — or for a UK manufacturer's product being considered on an international project — that dual evidence base removes a common headache. You are not choosing between a "European product" and a "US product"; you are specifying one membrane whose performance is documented against both regimes. ✅
Installed the same way
The certifications reflect Poseidon installed as intended: two cross-applied coats by spray, roller or brush to roughly 0.4–1.0 mm dry film, with reinforcement at internal corners, junctions and around pipe and drain penetrations, before tiling with a suitable C2 cement-based adhesive. The detailing is what turns tested performance into a watertight room.
The bottom line
Meeting ANSI A118.10 and A118.12 puts Poseidon among the membranes a US tile installer can specify with confidence for both waterproofing and crack isolation — and pairing that with the EU ETA makes it a rare membrane that is genuinely specifiable across markets.
Review the numbers in full on the full test data & certifications, or take a closer look at Poseidon.