Advanced Multi-Surface Waterproofing Solution
Stop Leaks Before They Start. Protect Your Roofs, Gutters & More.
RCM Leak Block is your go-to, high-performance waterproofing coating designed for long-lasting leak protection on a wide variety of surfaces. From fibre cement roofs and chromadek to Nutec tiles, AluZinc sheeting, and even garden pots, this versatile, water-based solution delivers powerful, durable waterproofing you can trust.
With superior flexibility and advanced adhesion properties, RCM Leak Block ensures cracks, gaps, and vulnerable areas stay sealedeven in coastal conditions. Easy to apply by brush or roller, this product is ideal for DIY homeowners and professionals alike.
Key Features:
Suitable for Multiple Surfaces Works on fibre cement, Nutec, chromadek, metal, garden pots, and more
Superior Flexibility & Crack Bridging Perfect for roofs, flashing, and detailing
Ideal for Membrane Applications Excellent adhesion with reinforcement membranes
Coastal Grade Protection Third coat recommended for high-exposure environments
Low Odour & Eco-Friendly Safe, water-based formula
Up to 3-4 Years Maintenance-Free Performance
Perfect For:
- Roofs, flashing, and parapets
- Window sills, garden pots, wall edges
- Nutec sheeting, AluZinc, Chromadek panels
- Garden features needing waterproofing
Application Made Simple:
1 Surface Prep Clean and dry thoroughly. Remove loose particles, grease, or fungal growth
2 Prime if Required Use primers on rust-affected or difficult surfaces (e.g., galvanized sheeting, Nutec, asbestos)
3 Apply 2 Coats By RCM Paint Brush or roller. A third coat is recommended in coastal areas
4 Membrane Use For added reinforcement on cracks and joints
Dry to Touch: ~2 hours @ 25°C
💧 Maintenance Coat Recommended: Every 3-4 years
Technical Specifications:
- Finish: Matt, smooth
- Coverage: Approx. 6m² double coated (0.81kg/m² depending on surface)
- Pack Sizes: 5L | 6kg | 7.5m² (double coated)
- VOC: Low
- Recommended Film Thickness: 1000 microns WFT
- Application Temperature: 1030°C, RH 85%
In addition, you can add the following to enhance your waterproofing system,
RCM Paint Brush
RCM Waterproofing Membrane
RCM Water Based Plaster Primer
RCM Acid Metal Etch Primer
Safety First:
- 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
Technical Data Sheet
Colours
What's in the box:
1 x RCM Leak Block Waterproofing Coating
