How to Apply Liquid Rubber

Step 1: Inspect the Surface

Before applying any waterproofing product, inspect the surface properly. Look for cracks, leaks, rust, loose paint, failed coatings, damaged joints, water pooling and signs of water ingress.

Pay close attention to common leak points such as:

• Roof edges
• Gutters
• Flashings
• Screws and fixings
• Sheet overlaps
• Concrete cracks
• Wall junctions
• Parapet corners
• Drainage points

Identifying problem areas before application helps ensure the right products are used from the start.

Step 2: Clean and Prepare the Area

Surface preparation is one of the most important parts of waterproofing. Liquid rubber needs a clean, stable surface to bond properly.

Remove:

• Dirt
• Dust
• Grease
• Loose paint
• Rust
• Flaking coatings
• Unstable material
• Old failed sealants where necessary

The surface should be sound, dry and free from anything that may affect adhesion. For metal surfaces, remove loose rust and unstable coatings. For concrete, remove dust, loose material and any weak surface layers.

Skipping this step can lead to poor bonding and reduced waterproofing performance.

Step 3: Prime Where Required

Some surfaces require a primer before applying liquid rubber. Primer helps prepare the substrate and improve adhesion between the surface and the waterproofing membrane.

Primer may be required on:

• Porous concrete
• Metal surfaces
• Previously coated areas
• Weathered or difficult substrates
• Surfaces with inconsistent absorption

The correct primer depends on the surface type, condition and application area. If you are unsure, get product advice before applying the waterproofing system.

Step 4: Reinforce Cracks, Joints and Problem Areas

Cracks, joints, corners and roof details are often the first places where leaks begin. These areas should be reinforced before applying the main liquid rubber coating.

Use U-Proof Fibre Filler on areas such as:

• Concrete cracks
• Roof joints
• Flashings
• Gutters
• Roof edges
• Sheet overlaps
• Screw and fixing points
• Parapet wall junctions
• Balcony corners
• Drainage points

Reinforcing these areas helps bridge gaps and adds strength where the waterproofing system needs it most.

Step 5: Apply U-Proof Liquid Rubber

Once the surface is clean, prepared, primed where required and reinforced, apply U-Proof Liquid Rubber to create the main waterproofing membrane.

Liquid rubber can typically be applied by brush, roller or suitable application method depending on the project area.

Apply evenly across the prepared surface, making sure vulnerable details are fully covered. Work methodically and avoid leaving thin, missed or uneven areas. Where more than one coat is required, follow the correct drying and recoat guidance for the product.

The goal is to create a continuous, seamless waterproofing membrane over the prepared area.

Step 6: Allow the System to Cure

After application, allow the waterproofing system to cure properly. Curing time can depend on weather, temperature, humidity, surface conditions and application thickness.

Avoid exposing the area to unnecessary traffic, water or finishing layers before the system has cured sufficiently.

Once cured, the liquid rubber forms a flexible protective barrier that helps prevent water penetration and withstand weather exposure.

Step 7: Inspect and Maintain the Finished Surface

After curing, inspect the waterproofed area. Check that the surface is fully covered and that cracks, joints, edges and detailed areas are properly sealed.

Regular maintenance can help extend performance over time. Inspect waterproofed surfaces after heavy weather, seasonal changes or visible wear.

Look out for:

• New cracks
• Damaged coatings
• Blocked gutters
• Standing water
• Loose material
• Rust returning on metal areas
• Movement around joints and edges

Small maintenance repairs are usually easier and more cost-effective than waiting for larger leaks to develop.