Thompsons Water Seal - Ronseal

Thompsons Water Seal is designed for long-lasting protection, typically lasting for several years. The exact duration depends on environmental conditions, exposure, and the specific surface type. While the surface beading may fade, the deep protection remains effective long after.

No, Thompsons Water Seal is designed for use on bare, porous masonry and stone. It should not be applied over existing sealers, paints, or other surface coatings as it needs to penetrate the substrate directly. Ensure the surface is completely free of these before application.

Unlike many standard waterproofers that form a surface film, Thompsons Water Seal uses advanced hydrophobic technology to penetrate deeply into dry, porous materials. This creates a more durable, long-lasting, and breathable barrier that protects the structure from within.

Thompsons Water Seal is formulated for exterior use. While specific environmental impact data should be consulted on the product's safety data sheet, it is generally intended to protect building materials from water damage, contributing to structural longevity.

Thompsons Water Seal is specifically designed for exterior applications on masonry and stone. It is not recommended for interior use.

The product requires approximately 24 hours to cure and become fully effective against rain. If heavy rain occurs before this period, the protection may be compromised, and reapplication might be necessary once the surface is dry.

Thompsons Water Seal dries to an invisible finish, preserving the natural texture and color of your stonework and brick. In some cases, highly porous materials may appear slightly darker, which is a sign of effective penetration.

Ensure the product was applied to a dry, porous surface and that it was allowed to cure fully (at least 24 hours). If the surface is still highly absorbent, a second coat may be needed after the first has dried. Check that no liquid water is pooling on the surface, which could indicate a drainage issue with the structure itself.

This can occur if the product was applied unevenly or if there were significant variations in surface porosity. Try to apply a second, even coat over the entire affected area to blend the finish. Avoid over-application in certain spots.

While designed to dry invisibly, some very porous materials may show a slight darkening or sheen when treated. This is normal and indicates good penetration. Test on an inconspicuous area first if preserving the exact original appearance is critical.

The surface may not be porous enough, or it might be sealed, painted, or contaminated with grease or silicone. Ensure the surface is clean and porous. Thompsons Water Seal is not effective on non-porous or sealed surfaces.