How to use this database
Start with the application tile: exposed roof shows only membranes the manufacturer rates to be left open to the sun and weather; covered roof, balconies and the wet area tiles do the same for their conditions, and below ground covers retaining walls, basements and tanking. Then cut the list by membrane type, by the AS/NZS 4858 movement class the junction needs, and by whether the finished surface carries foot or vehicle traffic. The TDS button on every card opens the manufacturer's current technical data sheet, which is the document that governs what the membrane may actually be used for.
Exposed or covered: the first question
The single biggest selection error we see as waterproofing engineers is a membrane built to be covered left exposed. A membrane under tiles, screed or ballast is protected from UV; the same chemistry left open to the sun chalks, embrittles and cracks years early. Manufacturers state exposure plainly in the TDS, which is why this database filters on it first and links every product straight to that document. External above-ground membranes are tested to AS 4654.1 and installed to AS 4654.2; internal wet area membranes are tested to AS/NZS 4858 for use under AS 3740.
What the movement class means
| Class | AS/NZS 4858 | Where it's required |
|---|---|---|
| Class I | Rigid — about 1 mm of movement | Stable substrates, bonded screeds |
| Class II | Flexible — about 2 mm | Most internal wet areas on concrete |
| Class III | High extensibility — about 5 mm | Junctions and substrates that move: timber floors, sheet flooring, external decks |
The class is a property of the whole installed system at the joint, so the TDS and the manufacturer's detail govern. Where a substrate moves more than the class allows, the design needs a bond breaker or a different membrane, which is exactly the judgement a waterproofing engineer signs for.
Why the TDS matters on site
The technical data sheet is the manufacturer's statement of what the membrane is, where it may be used, the substrates and primers it needs, its cure times and its film thickness. When a certifier, builder or waterproofer needs an answer standing on the slab, the TDS is the document that settles it — and it changes as products are reformulated, which is why every link here goes to the manufacturer's site rather than a stored copy.
Questions we get asked
What is a Class I, II or III membrane?
AS/NZS 4858 classes membranes by movement capability: Class I rigid (≈1 mm), Class II flexible (≈2 mm), Class III high extensibility (≈5 mm). The junction that moves most sets the class the job needs.
Can an internal membrane be used on a balcony?
No — external membranes must be tested to AS 4654.1 and installed to AS 4654.2. Some products carry both internal and external approvals; the TDS says so.
What does "trafficable" mean?
That the cured membrane itself may be walked on (pedestrian) or driven on (vehicular) as the finished surface. Membranes marked non-trafficable must be covered before the area is used.
Why do some products have no class?
Primers, admixtures, crystalline coatings and some below-ground sheet systems sit outside AS/NZS 4858, so no class applies.