RCM Leak Block Waterproofing Coating

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 sealed—even 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:

1️⃣ Surface Prep – Clean and dry thoroughly. Remove loose particles, grease, or fungal growth
2️⃣ Prime if Required – Use primers on rust-affected or difficult surfaces (e.g., galvanized sheeting, Nutec, asbestos)
3️⃣ Apply 2 Coats – By RCM Paint Brush or roller. A third coat is recommended in coastal areas
4️⃣ 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 (0.8–1kg/m² depending on surface)
• Pack Sizes: 5L | 6kg | 7.5m² (double coated)
• VOC: Low
• Recommended Film Thickness: 1000 microns WFT
• Application Temperature: 10–30°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