Dry-Treat’s STAIN-PROOF™ has been used to seal the highly porous green limestone paving of London's prestigious Kings College. The limestone paving had been rejuvenated and treated to improve traction when wet. A special sealer was needed which would not reverse the improved surface traction.

Anti-slip treatments make the surfaces rougher and more porous, and therefore harder to clean, more prone to staining, and more prone to water ingress which can encourage moss and mildew growth, salt efflorescence, freeze-thaw spalling and other structural damage. So the sealer chosen also had to have excellent oil and water repellency, be fully breathable to allow moisture to evaporate from underneath, penetrate sufficiently deep to protect from structural damage caused by water, and not break down under a rigid commercial cleaning regime.

Dry-Treat's STAIN-PROOF™ only works from inside the pores of the material - it forms no coating on the surface and therefore does not affect the slip resistance of treated surfaces. The chemistry of STAIN-PROOF™ is unique. Specially designed molecules which are thousands of times smaller than competitor sealers penetrate much deeper into the material, and also bond by chemical reaction to permanently become part of the material. A sufficiently deep,  permanent water and oil-repellent barrier is created, which is able to effectively protect against staining and even structural damage caused by water ingress, and which stands up to highly alkaline cleaning chemicals and even high pressure hosing.

The highly porous limestone was sealed with two coats of STAIN-PROOF™ by Accredited Application Company Really Safe Flooring, which specialises in slip resistance treatments, restoration and sealing of porous surfaces. This project is backed by a standard, 'no-strings' STAIN-PROOF™ 15-year Performance Warranty.