Some customers believe that our treatments will make their sandstone or limestone 'salt safe'. This is not accurate. There is no doubt that our sealers will provide a considerable long-term benefit in resisting the ingress of water and salt into the stone. However, the treated stone will not necessarily become 'salt safe'. Rather, it becomes far more resistant to the ingress of salt. The amount of salt already in the stone prior to treatment, the proximity to salt water, the type and concentration of the salts in the water, the type and quality of the stone and sub-soil drainage will all affect the durability of the stone. Please note that although we believe our sealers are the best available on the market they must be applied correctly. With proper application sealers will significantly improve the durability of the stone in a salt water environment.

Sodium chloride salt (the main salt in sea water) is partially damaging as it readily forms a strong cubic crystal that can rupture the stone matrix. Care must be taken not to trap the salts just below the surface of the stone. This condition is known as crytoflorescence. If the salts are stopped just below the surface, for instance because not enough sealer is applied, the water will still evaporate, depositing the salts behind the surface, which then crystallize. The expanding salt crystals can exceed the tensile strength of the stone and cause spalling or disintegration of the stone. So, how much is enough sealer? This can be worked out by testing a piece of sample stone with the treatment at the proposed application rate. Once the treated stone is cured (two weeks for STAIN-PROOF^® 40SK Consolidator & Water Repellent, formerly known as DRY-TREAT 40SK™), the stone is broken and soaked in water. The depth of penetration of the treatment is that part from the surface that does not absorb the water. For soft sandstone you would need at least 12 mm (1/2 inch) depth of penetration.

To ensure the maximum protection of stone in harsh saltwater environments 'dip sealing' the stone is highly recommended. This is done by fully immersing the stone in a bath filled with 40SK Consolidator & Water Repellent, typically for 30 seconds. Please note that by sealing the underside of the stone this will reduce the adhesion between a plain cement and sand mortar mix and the pavers. This problem is overcome by using a quality brand adhesive such as the Davco SE-7 and Davelastic or, Bostik Landscape Adhesive, which all have wetting agents. In this case the adhesion is actually improved as the treatment stops water loss of the adhesive to allow it to fully cure. Also make sure any parts of the stone latter exposed due to cutting are also treated. Otherwise this is will be a potential point of entry for the water-borne salts.