Stormdry Repointing Additive No. 2 500ml

Stormdry Repointing Additive No.2 is a flexible waterproofing admixture developed for use in sand:cement repointing mixes. It is ideal for applications where masonry is exposed to heavy rainfall or potential flood conditions, including lower courses and exposed walls in high-risk areas. The additive is mixed into the gauging solution at a ratio of 1 part additive to 4 parts clean water and then added to the dry mortar blend. It can be used with both cement-based and lime-based mortars, making it suitable for traditional and modern construction. With proper application, the repointed mortar becomes significantly more water-resistant, improving the overall resilience of the wall against liquid ingress. Performance tests show that Stormdry Repointing Additive No.2, when used in combination with Stormdry Masonry Protection Cream, drastically reduces water flow through masonry. For example, at a 600mm flood height, a single-skin Fletton brick wall treated with this system sees water ingress reduced from 12.5 litres per square metre per minute to less than 0.2 litres. One 500ml container treats approximately 2.5 m2 of repointed masonry. The white milky liquid comes ready to dilute and is easy to blend into the mortar mix. Suitable for use on both new and historic structures, it enhances mortar durability while allowing the wall to retain its aesthetic finish. Stormdry Repointing Additive No.2 is fully compatible with best-practice repointing techniques such as bucket handle tooling and conforms with guidance provided in BRE Good Repair Guide 24 on repointing external brickwork walls. Proper curing, particularly in colder conditions, is essential for achieving long-term performance.