WATERSTOP Emergency Waterproof Coating

• High-performance roof leak repair sealant that stops leaks instantly

• Instantly waterproof roof sealer can be applied to wet and dry surfaces

• No priming required, apply directly to substrates including concrete, stone, wood, metal, zinc, clay, tiles, slate, felt, polystyrene and most plastics

• Paint on waterproofer - apply straight from the tin with a disposable brush

• Solvent, bitumen, and isocyanates-free formula

• Long-lasting protection and resistance to cracking, UV, frost, and temperature variations

Preparation

• Ensure the surface is sound, clean and free from dust, dirt, oil, grease, loose paint, stone chippings, rust, standing water and contaminants. Remove moss, lichen and other organic growth.

• New cement-based surfaces, mortar and brickwork must be allowed to cure for at least two months before applying the paint on waterproofer.

• Protect windows, frames and surrounding areas with plastic sheeting before application.

• The emergency roof seal can be applied to damp surfaces - just brush away excess water. No primer is required.

• Ensure the temperature stays above +5°C when storing, applying, and curing WATERSTOP Emergency Waterproof Coating. If stored below +15°C, bring to room temperature two hours before use.

Application

• Remove the lid and pierce the film.

• Apply the roof leak repair sealant immediately using a disposable brush once opened, as it will start to cure.

• Cover all gaps or cracks completely - the roof sealant for leaks will bridge and seal them permanently. Fill cracks over 5mm and cover with flexible scrim bedded into the coating.

• Apply two coats at minimum thickness of 1.5mm per coat. Ensure the coating is continuous and uniform, working it well into the surface.

• Let the first coat dry (around four hours at +20°C) before applying the second coat. The surface should be walkable before the application of the second coat. Cooler temperatures require longer drying times.

• For corners or areas prone to movement or cracking, bed reinforcing scrim into the first coat of the emergency roof seal. Press the reinforcing scrim into the coating and apply the second coat after four hours.

• Refer to the Technical Data Sheet for full Instructions on how to apply.

Cleaning

• Remove any splashes of WATERSTOP Emergency Roof Coating immediately as dried product is difficult to remove. Discard the brushes after use.

Can you paint over roof sealant?

No - painting over WATERSTOP Emergency Roof Coating is not recommended. The emergency roof seal is designed to remain flexible to accommodate roof movement and temperature changes. If painted over, the rigid paint layer can crack and peel over time as the coating expands and contracts.

How long does roof sealant last?

WATERSTOP Emergency Roof Coating excels at quick, emergency repairs, and can last up to 5 years, depending on general wear and the quality of the application. The emergency roof seal is designed to remain flexible to accommodate movement as temperature changes. However, if signs of deterioration appear, reapplication or repairs may be needed to maintain an effective, waterproof seal.

If longer-lasting maintenance is required, consider using Bostik WATERSTOP Flexible Waterproof Coating, which can last up to 10 years. Designed with durability and maintenance in mind, it provides an extended waterproofing solution to keep roofs protected for longer.

Can you apply roof sealant in the rain?

Yes - you can apply WATERSTOP Emergency Waterproof Coating in the rain. The specialised roof sealer is designed to work effectively even in wet conditions, making it ideal for emergency leak repairs during rainy weather. The coating adheres directly to wet surfaces and immediately stops leaks. Simply brush it on using a disposable brush, and the coating will create a durable, weatherproof seal that protects against ongoing weather exposure, UV, frost, and temperature changes.