Liquid Waterproofing

Liquid Waterproofing Solutions

Liquid-applied systems are an increasingly popular choice for flat roofs, balconies and terraces because they form a seamless waterproof barrier that follows every contour of your structure. Unlike sheet membranes, these coatings cure in situ to create a monolithic surface with no laps, joints or fixings that can let water in.

Why use liquid waterproofing?

Liquid waterproofing provides a combination of flexibility, durability and ease of installation. Sika’s Sikalastic D-10 RoofPro membrane is a single-component, moisture-triggered polyurethane coating that cures to form a seamless waterproof surface. It’s supplied ready-mixed in tins and can be applied by spray, brush or roller. Once laid it cures quickly, resists rain almost immediately and remains flexible even at low temperatures, providing a long-lasting finish suitable for new builds and refurbishments alike.

To control moisture movement within the roof build-up, Sika’s S-Vap 5000E SA vapour control layer offers multi-layer, self-adhesive protection made from polymer-modified bitumen reinforced with glass fibre and topped with aluminium foil. It adheres directly to concrete, metal or timber decks without fasteners, withstands high wind loads, and even provides temporary waterproofing for up to four weeks – ideal for managing site conditions during construction.

For complex roof details and penetrations, Sika Reemat Premium glass-fibre mat provides structural reinforcement within the liquid coating. It adjusts easily to corners and upstands, ensuring consistent coating thickness and improving crack-bridging and mechanical strength. It’s particularly effective on roofs with irregular shapes or detailing.

Sika also supplies a complete system of primers, adhesives and sealants designed to enhance performance and ease of application. Primer 600 is a one-part, synthetic-rubber-and-resin primer that promotes strong adhesion of membranes without the need for hot works. Sikalastic Metal Primer protects metal substrates against corrosion and improves bonding, while Sika Concrete Primer LO is a low-odour, rapid-curing option for cementitious surfaces. For refurbishments, Sika Reactivation Primer reactivates existing Sikalastic coatings so that new layers can be applied beyond the normal recoating window.

When bonding or sealing details, Sika Stixall provides high initial grab and reliable adhesion on virtually any substrate, even in damp conditions. For movement joints and façade work, Sika flex-250 Facade offers a flexible polyurethane sealant with exceptional elasticity, UV resistance and weather durability.

All of these components work together to form a comprehensive liquid waterproofing system – from vapour control through to the final coating – ensuring maximum longevity and watertight performance.

Installation and support

Liquid waterproofing systems are designed to be straightforward to install. Surfaces must be structurally sound, clean and dry, and some substrates may require priming. Products like Primer 600 are easily applied by brush or roller to enhance adhesion, while S-Vap 5000E SA adheres directly to the deck without mechanical fixings. Membranes should be laid in dry weather at temperatures above 5 °C, and reinforcement matting should be embedded into the base coat to achieve the correct thickness and strength.

Sika provides comprehensive data sheets, step-by-step guides and training videos to help installers achieve professional results, whether you’re a DIY enthusiast or an experienced roofer.

Quality, sustainability and peace of mind

Sika has been developing liquid waterproofing technology for decades and operates a global network of manufacturing plants. The company has subsidiaries in over 100 countries and produces materials in more than 400 factories, ensuring reliable supply and local technical support.

Its facilities are certified to ISO 9001:2015 for quality management and ISO 14001:2015 for environmental protection, with additional accreditations for health and safety. Choosing Sika therefore means investing in proven performance, consistent quality and responsible manufacturing.

Frequently asked questions

1. What’s the difference between GRP fibreglass roofing and liquid waterproofing?
GRP roofs use rigid glass-fibre laminates and are ideal for small to medium-sized roofs. Liquid waterproofing systems, like Sikalastic D-10 RoofPro, cure to form a seamless, elastomeric membrane that adapts to complex details and can be reinforced with glass-fibre matting. They’re suitable for both new builds and refurbishments and often require fewer trims and joints.

2. Are Sika liquid products suitable for domestic roofs?
Yes. Systems such as Sikalastic D-10 RoofPro and S-Vap 5000E SA are widely used on commercial and residential projects. They’re ideal for garages, balconies and extensions, forming seamless waterproof coatings that can be re-coated to extend service life.

3. Can liquid waterproofing be applied in cold weather?
Many Sika systems cure effectively at low temperatures. Sikalastic D-10 RoofPro remains flexible even when cold, though primers should only be applied in dry conditions above about 5 °C. Always refer to the individual product data sheets for temperature guidance.

4. What surface preparation is needed?
Surfaces must be sound, clean and dry. Concrete and timber decks may need priming with Primer 600 or Concrete Primer LO, while existing membranes must be clean before applying Reactivation Primer to receive a new coat. Always follow Sika’s preparation guidance for each substrate.

5. How long do liquid waterproofing coatings last?
When installed to the manufacturer’s specifications, Sika’s liquid membranes provide long-term protection. Sikalastic D-10 RoofPro typically carries a ten-year guarantee and can be re-coated to extend its lifespan. Regular inspection and maintenance will ensure continued watertight performance.

Whether you’re refurbishing a small domestic roof or waterproofing a large commercial building, Sika’s liquid systems deliver flexible, long-lasting protection. With membranes, vapour control layers, primers, adhesives and reinforcement available from JJ Roofing Supplies, you have everything needed to create a robust, seamless roof covering that stands up to the British weather.