Collection: Salt Barrier

White spots on the wall — known as salt efflorescence — are not the problem themselves. Capillary moisture rising from deep within the wall carries dissolved salts, and when the moisture evaporates on the surface, the salts crystallize as a coating. Cleaning the surface is temporary: as long as the capillary moisture is active, the salt will return.

What is a salt barrier?

A salt barrier is a special indoor and outdoor coating that chemically blocks salt crystallization near the wall surface. It does not stop the capillary movement of moisture — which must be treated by injection or waterproofing systems — but prevents salts from reaching the surface and crystallizing there. This protects the lifespan of plaster and coverings.

When is a salt barrier needed?

Using a salt barrier is justified:

• On old brick and stone masonry where salt efflorescence is a recurring issue;
• In cellars and basements where capillary absorption regularly causes salt buildup;
• Before applying plaster where the wall’s salt concentration is known and high;
• Under coverings where salt efflorescence can weaken tile adhesive and grout bonds;
• As a supplement to a dehumidifying plaster system where salt treatment requires a separate step.

Relationship between salt barrier and dehumidifying system

A salt barrier alone is not sufficient to fully treat a damp wall — identifying the moisture source and applying the main treatment system (dehumidifying plaster, injection) is primary. The salt barrier is a complementary element that manages salt efflorescence, while the dehumidifying plaster controls moisture movement. Together, they form a complete system.

On which substrates can it be applied?

Salt barrier can be applied indoors and outdoors on brick, stone, concrete, and plaster surfaces. Some versions are formulated as paint, others as plaster additives. The application method depends on the substrate type and salt concentration — which can be determined by an on-site survey.

Browse our salt barrier products or request advice on assembling a comprehensive treatment system for damp walls.