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Expert roofing and cladding solutions for commercial properties, delivered with precision and care.
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Proudly British Owned & Operated
Expert roofing and cladding solutions for commercial properties, delivered with precision and care.
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Proudly British Owned & Operated
Specialist commercial roofing tailored to the unique demands of your industry.
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Proudly British Owned & Operated
See how we've transformed commercial properties across London and the South East.
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Proudly British Owned & Operated
Cold-applied liquid waterproofing for commercial flat roofs, balconies and complex details across London and the South East. Approved contractors for Kemper System and Soprema — seamless, guaranteed, no hot works required.
Liquid Waterproofing
Liquid waterproofing is one of the most versatile and effective flat roofing solutions available. Applied as a cold-liquid coating that cures to form a fully seamless, flexible membrane, it bonds directly to the substrate with no joints, laps or seams — which removes the most common failure points found in traditional flat roofing systems. It's particularly well suited to complex roof geometries, detailed areas around penetrations, rooflights and upstands, and projects where hot works are not permitted.
Exall Group are approved contractors for Kemper System and Soprema — two of the leading liquid waterproofing manufacturers in the UK. Both systems are cold-applied, BBA-certified and backed by long-term manufacturer warranties on qualifying installations. We've applied liquid waterproofing systems on commercial flat roofs, hospital balconies, roof terraces and complex multi-detail projects across London, Essex, Surrey, Kent and Hertfordshire.
Liquid waterproofing is equally effective as a new installation system and as a refurbishment solution — applied over existing substrates in sound condition without the need for a full strip. This makes it a cost-effective alternative to replacement on roofs where the structure is sound but the waterproofing has reached the end of its life.
Where liquid waterproofing is being considered alongside other flat roofing options, see our flat roofing and single ply pages for a comparison of available systems. A condition survey is the right starting point if you're unsure which system is appropriate for your building.
Our Work
A hospital ward faced water ingress from a roof balcony. Exall installed liquid waterproofing and interlocking rubber tiles.
Our Process
We inspect the existing substrate, drainage falls, upstands and details. We confirm the right system — Kemper System or Soprema — based on the substrate, use case and warranty requirements. For refurbishment projects, we assess whether the existing surface is suitable to receive the coating directly.
The surface is cleaned, primed and prepared to the manufacturer's specification. Any areas of deterioration are addressed before the liquid is applied. Getting the preparation right is critical — it's what the warranty depends on.
The waterproofing is applied in coats to the required finished thickness, with reinforcement fleece embedded at critical details. Upstands, outlets, penetrations and rooflights are detailed and sealed as part of the application.
On completion we carry out a full inspection of the finished surface and all details. The warranty is registered with the manufacturer directly. You receive documentation confirming the system specification, installation details and warranty terms.
Frequently Asked Questions
Liquid waterproofing is a cold-applied coating system that cures to form a fully seamless, flexible membrane directly bonded to the roof substrate. Unlike membrane systems, it has no joints or laps — the entire surface becomes a single continuous waterproofing layer. It is BBA-certified, cold-applied and available with long-term manufacturer warranties.
We are approved contractors for Kemper System and Soprema — two of the leading liquid waterproofing manufacturers in the UK. Both systems are BBA-certified and cold-applied. We specify the appropriate system based on the substrate, use case and warranty requirements.
Yes. One of the main advantages of liquid waterproofing is that it can be applied directly over existing substrates in sound condition — without the cost and disruption of a full strip. We assess the existing surface as part of our survey to confirm suitability.
No. Liquid waterproofing systems are cold-applied, which means they can be used on occupied buildings, in areas where hot works are not permitted, and on projects where fire risk from bitumen torching is a concern.
Qualifying installations with Kemper System and Soprema carry manufacturer warranties of up to 25 years. Warranties are only valid when the system is installed by an approved contractor to the manufacturer's specification — which is why approved installer status matters.
Liquid waterproofing is suitable for flat roofs, roof terraces, balconies, podium decks, gutters and complex detail areas. It works particularly well on roofs with multiple penetrations, rooflights or irregular geometry where membrane systems are difficult to detail correctly.
Yes. We cover the whole of London and the wider South East — including Essex, Surrey, Kent and Hertfordshire. Call 0800 255 0325 or use the contact form to discuss your project.
Tell us about your project and one of our commercial roofing specialists will get back to you within 24 hours.
