RCM Leak Block Waterproofing Coating Exterior Liquid Crack Filler  (5 L)

RCM Leak Block – Advanced Multi-Surface Waterproofing Coating Stop leaks before they start with RCM Leak Block, a premium, long-lasting waterproofing solution engineered for superior protection on a wide range of surfaces. Ideal for both DIY homeowners and professionals, this high-performance, water-based coating delivers maximum durability and flexible, crack-bridging resilience—perfect for roofs, gutters, garden features, and more. Versatile Protection for Multiple Surfaces Formulated to adhere to diverse materials, RCM Leak Block works seamlessly on fibre cement, Nutec sheeting, chromadek, AluZinc, metal, and garden pots, making it your all-in-one waterproofing solution. Outstanding Flexibility & Adhesion RCM Leak Block’s superior flexibility means it holds strong even in extreme temperatures and coastal environments, forming a robust, water-tight seal on cracks, gaps, flashings, parapets, and other vulnerable areas. Easy Application Designed for straightforward use, this product applies smoothly by brush or roller. Suitable for surface detailing and ideal for use with waterproofing membranes on joints and cracks. Key Features - Multi-Surface Compatibility: Fibre cement, Nutec, chromadek, AluZinc, metal, garden pots, and more - Superior Flexibility: Adjusts to surface movement, bridges cracks, and resists peeling or flaking - Exceptional Adhesion: Bonds strongly—even to difficult substrates - Coastal Grade Protection: Three coats recommended in high-exposure areas - Eco-Friendly, Low Odour: Safe, non-toxic, and water-based - Maintenance-Free Durability: Up to 3–4 years between recoats Perfect For - Roofs, flashing, parapets - Window sills, garden features - Nutec, AluZinc, and chromadek panels - Waterproofing decorative and practical outdoor surfaces Simple 4-Step Application 1. Surface Preparation: Clean, dry, and ensure the surface is free of dust, grease, and fungal growth. 2. Prime (if required): Use suitable primer for rusty or tricky surfaces like galvanized metal, Nutec, or asbestos. 3. Apply: Brush or roll on two coats of RCM Leak Block. Use three coats for optimal protection in coastal regions. 4. Reinforce: For cracks and joints, apply with a waterproofing membrane for extra strength. Drying Time: Touch dry in approximately 2 hours at 25°C Recoating Interval: Every 3–4 years for continued protection Technical Specifications - Finish: Matt, smooth - Coverage: Up to 6m² (double coated, 0.8–1kg/m² depending on surface) - Pack Sizes: 5L | 6kg | 7.5m² (double coated) - VOC: Low - Recommended Wet Film Thickness: 1000 microns - Application Conditions: 10–30°C, RH ≤85% Enhance Your Waterproofing System - [RCM Paint Brush](https://www.securadeal.co.za/products/rcm-paint-brush) - [RCM Waterproofing Membrane](https://www.securadeal.co.za/products/eco-rubber-waterproofing-membrane) - [RCM Water Based Plaster Primer](https://www.securadeal.co.za/products/eco-rubber-plaster-primer) - [RCM Acid Metal Etch Primer](https://www.securadeal.co.za/products/eco-rubber-acid-metal-etch-primer) Safety Information - Keep out of reach of children - Avoid eye and prolonged skin contact - Non-toxic, non-flammable - Dispose of according to local regulations Hazard Statement: May cause allergic reaction View [Technical Data Sheet](https://cdn.shopify.com/s/files/1/0420/3570/8056/files/Leak_Block_TDS.pdf?v=1750166513) See [Available Colours](https://cdn.shopify.com/s/files/1/0420/3570/8056/files/RCM_Leak_Block_colours.png?v=1750848209) What’s in the box: 1 x RCM Leak Block Waterproofing Coating