Osmotic slurries

Why they are still widely used

They are the only waterproofing family genuinely compatible with a cementitious substrate: same chemical nature, same hygrometric behaviour, adhesion by curing rather than by bonding. They adhere to damp substrates without a primer, which on a basement or a freshly cast structure is the normal condition, not the exception.

They can also be recoated with cementitious adhesives and renders with no intermediate layer, which is why they remain the standard choice under tile.

Rigid or flexible

Rigid single-component slurries are used where the substrate is stable and no movement is expected: pre-sealing against the ground, renovation work, sulphate-bearing substrates.

Flexible two-component slurries, polymer-modified, add the ability to bridge cracks, even at low temperatures. This is what is needed on tanks, containers, swimming pools and anywhere the structure is subject to dimensional movement.

How to read the classifications

EN 14891 qualifies liquid-applied waterproofing products used under tiling, with codes such as CM O1 P where CM indicates the cementitious binder, O1 the crack-bridging capability and P resistance to chlorinated water. EN 1504-2 instead qualifies surface protection systems for concrete. A product declaring both covers installation under tile and structural protection alike.