Services / Single Ply Roofing

    Single Ply Flat Roof Alternative

    Single-ply membranes are popular for new builds, but they puncture easily and rely on seams that can open over time. We install Ultraflex over single-ply and other existing roofs, creating a seamless, fully bonded waterproof layer with no joints and a 20-year guarantee.

    • Punctures from stones and grit
    • Seams opening
    • Shrinkage and stress
    • Leaks around penetrations
    Instant Estimate
    Common problems

    The problems with single ply flat roofs

    Single-ply roofs are thin, flexible membranes that waterproof through sheet coverage and sealed joints. That makes them vulnerable to punctures, seam failure and weather damage.

    • Small holes from stones and grit

      Foot traffic, wind-blown gravel, and maintenance work easily puncture the thin membrane. Even small holes let water in and are hard to locate.

    • Joints can open

      Seams and laps are sealed with tape or heat welding. Over time these joints can open, peel or lift, creating direct leak paths across the roof.

    • Shrinkage and stress

      Single-ply membranes can shrink, pulling away from upstands, drains and edge details and stressing the sealed joints.

    • Poor detailing around penetrations

      Rooflights, pipes, corners and upstands need careful flashing. Every detail is a potential failure point when the sheet is cut and sealed.

    • UV and weather damage

      Sun exposure and ponding water degrade the surface, reducing flexibility and making the membrane more brittle and puncture-prone over time.

    Single-ply flat roof with visible punctures, open seams and surface damage
    Single Ply vs Perlini System

    Why we install our waterproofing system over single ply

    Single-ply roofs are vulnerable to punctures from stones and grit, and their seams can open as the membrane ages. Our waterproofing system is a seamless, fully bonded liquid membrane with no joints to fail, and it can be applied directly over an existing single-ply roof, backed by a 20-year guarantee.

    Same roof after being overlaid with seamless Ultraflex liquid waterproofing
    Single-ply flat roof with loose, worn membrane sheet coming off
    BeforeAfter
    Powered by Ultraflex

    One of the best flat roof waterproofing systems on the market

    Whatever flat roof job you have (installation, repair, replacement, or an asphalt, GRP, EPDM or torch-on felt overlay), we install the Ultraflex cold-liquid waterproofing system. It's the most durable, cost-effective, and reliable flat-roof solution available.

    By overlaying your existing roof with Ultraflex, we save you the cost and disruption of a full strip-out while delivering a fully bonded, seamless waterproof layer backed by a 20-year guarantee. We go in, repair your existing roof and seal it for decades of protection. If needed, we can apply bespoke finishes and solutions post-waterproofing.

    Ultraflex flat roof installation

    Why we install Ultraflex on every job

    Faster installation

    Fast-curing and rainproof in as little as 30 minutes.

    Up to 50% cost savings

    Overlay your existing roof and avoid strip-out costs.

    20-year guarantee

    Proven waterproofing built for long-lasting protection.

    100% Compatible

    Torch-on felt, asphalt, GRP, timber, concrete, and virtually any roof surface.

    Safer installation

    Cold-liquid application, eliminating fire risk.

    Seamless waterproofing

    No joints or laps, just one fully bonded waterproof layer.

    How we work

    1. 1

      Instant Estimate

      Fill out our cost estimate tool to receive a fast, ballpark price based on your project details. It's a quick way to understand likely costs before moving forward.

    2. 2

      Site Visit + Detailed Quote

      We carry out a site visit where needed to assess your roof in detail, then provide a clear, itemised quote with no hidden costs so you know exactly what to expect.

    3. 3

      Installation

      Our trained team prepares the surface and installs the Ultraflex system, delivering a seamless, fully bonded waterproof finish built to last.

    4. 4

      Sign-off & 20 Year Guarantee

      We inspect the roof, hand over your 20-year guarantee documentation, and leave the property spotless.

    How Ultraflex compares

    See how our Ultraflex cold-liquid waterproofing system stacks up against traditional flat roof systems across the things that matter most.

    CriteriaUltraflexGRPEPDMAsphaltFelt
    Seamless, fully bonded
    Yes
    Yes
    No
    No
    No
    Cold-applied (no flame)
    Yes
    Yes
    Yes
    No
    No
    Rainproof in 30 minutes
    Yes
    No
    No
    No
    No
    Overlay existing roof
    Yes
    No
    No
    No
    Yes
    20-year guarantee
    Yes
    Yes
    Yes
    No
    Yes
    Cost-effective long-term
    Yes
    No
    Yes
    No
    No
    Resists cracking & shrinking
    Yes
    No
    Yes
    No
    No
    Suitable for complex detailing
    Yes
    Yes
    No
    No
    No

    Ultraflex over an existing single-ply roof avoids the cost of a full strip-out and removes the risk of punctures and open seams. Use our estimator for a personalised quote.

    Ultraflex FAQs

    The most common questions we get asked about the Ultraflex cold-liquid waterproofing system.

    Manufacturers typically offer twenty to twenty five year guarantees, and the sheet material can achieve that. Whether a particular roof does depends on the quality of the hot air welding, the amount of foot traffic it receives, the number of penetrations, and whether small punctures are found and repaired before water reaches the insulation.

    Yes, provided the insulation below is dry and the membrane is still adhered or fixed soundly. After cleaning, adhesion testing and priming for PVC or TPO, the liquid system is applied over the whole roof, sealing the existing welds, fixings and details under one seamless membrane.

    It is genuinely difficult, because water entering a puncture can travel a long way through the insulation before it shows inside. We survey the roof surface systematically, check every weld, fixing and detail, and use moisture readings to map where water has spread. This is exactly the problem a fully bonded membrane removes for the future.

    The sheet is only a millimetre and a half to two millimetres thick and it sits over compressible insulation, so any point load concentrates on a very small area. Grit under a boot, a dropped fixing, ladder feet and scaffold boards are the usual culprits, and roofs with plant or solar panels that need regular access accumulate damage fastest.

    Yes. Cold liquid overlays are widely used on commercial and public buildings precisely because they avoid hot works, avoid a strip-out, and let the building stay in use throughout. We have applied the system on hospital, high-rise and commercial roofs across London and can phase the work to suit access restrictions.

    They stay where they are and keep doing their structural job of holding the build-up down. The new membrane goes over the top of them and over their welded patches, so the fixing heads are no longer a point at which the waterproofing is penetrated.

    Services tailored to your flat roof, we work on any job.

    From new installations and full system refurbishments to targeted leak diagnostics and repairs, every project is carried out by our in-house specialists using premium, manufacturer-approved liquid waterproofing systems.

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