Specialist flat roofing services
Single-ply specialists from start to finish — installation, maintenance, leak detection and the wider works that keep a flat roof watertight for decades. Explore each service below.
Everything a flat roof needs, from a single-ply specialist
JLH installs one family of systems — hot-air welded single-ply PVC, with liquid waterproofing for the details a sheet cannot reach — and offers every service a flat roof needs across its life. Choose the one closest to your situation, or start with a free survey and let us recommend.
Single-Ply PVC Installation
Seamless, mechanically fixed or fully adhered single-ply PVC membranes — the premium, long-life flat roof system for new builds, extensions and replacements.
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Roof Maintenance
Planned, proactive maintenance and refurbishment that extends roof life, protects your warranty and stops small faults becoming expensive failures.
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Electronic Leak Detection
Pinpoint the exact source of a leak with non-destructive electronic testing — followed by a clear report and a precise, lasting repair.
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Flat Roof Replacement
Strip your old, failed flat roof and re-roof with a modern single-ply system — warm-roof insulation upgrades to meet current standards.
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Commercial Roofing
Single-ply systems for warehouses, units, offices and schools — minimal disruption, full documentation and long-term performance.
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Roof Lanterns & Skylights
Architectural roof lanterns and rooflights, perfectly detailed and watertight — bringing light into high-end flat-roof spaces.
Learn moreWhich flat roofing service do you need?
Most enquiries start with a symptom rather than a service. This is how we usually match one to the other:
| Your situation | Usual answer | Why |
|---|---|---|
| Water coming in, source unknown | Electronic leak detection | Finds the exact breach without cutting the roof; the repair is then small and certain. |
| Felt or GRP roof 15+ years old, blistered or cracked | Flat roof replacement | Patching an end-of-life covering buys months. A welded single-ply warm roof buys decades. |
| New extension, garden room or dormer | Single-ply PVC installation | Specified with your builder from the deck up: falls, insulation, kerbs and trims. |
| Roof is fine and you want it to stay that way | Planned maintenance | Annual inspection, outlet clearance and a photo report protect the warranty and the ceiling below. |
| Warehouse, unit, office or school roof | Commercial roofing | Overlay or refurbishment planned around your operation and documented for insurers. |
| Orangery, lantern or rooflight, new or leaking | Roof lanterns & skylights | The kerb is the critical detail; we build it and weld the membrane over it in one skin. |
Still unsure? A free survey settles it. We look, we explain, we quote in writing — no pressure and no charge.
Why we only install single-ply PVC
A flat roof fails at its joints. Felt relies on torched or bonded laps and GRP on a rigid resin bond, and both give up when the deck moves, the sun bakes them or water sits on them for a week. Single-ply PVC sheets are hot-air welded to each other, fusing the whole roof into one continuous skin with a design life of 30–40 years or more. Because it is all we fit, our roofers weld it every working day, we hold manufacturer approval across eight systems, and we can back every roof with a 20-year workmanship warranty. The full comparison is in single-ply vs felt vs GRP.
The same four steps, whatever the service
Free Survey
We visit, measure and look at the deck, falls and details — and tell you honestly what the roof needs.
Written Spec & Quote
A fixed price naming the membrane, insulation, fixing method and every detail, so quotes can be compared like for like.
Installation
Manufacturer-trained roofers, welded and probe-tested seams, a tidy site and a watertight roof every night.
Warranty & Aftercare
Sign-off, your 20-year workmanship warranty in writing, and optional planned maintenance.
Choosing a flat roofing service
Can you repair my roof, or will you always recommend replacing it? +
If the covering is basically sound and the fault is local, we repair it. If it is widely worn, on several layers or the deck has gone, replacement is better value and we say so. The free survey is where we tell you which, honestly.
Do you install felt or GRP as a cheaper option? +
No. We only fit single-ply PVC and liquid systems because they outlast and outperform both, and because specialising is what lets us guarantee the workmanship for 20 years.
Do you work on roofs you didn't install? +
Yes — leak detection, repairs and planned maintenance on existing single-ply and other flat roofs are a large part of our work.
How quickly can you survey and start? +
We aim to reply the same working day and arrange the survey at a time that suits you. Start dates depend on the season and the size of the job; we give you a realistic one with the quote.
Are you manufacturer-approved? +
Yes — trained and approved across Sika, Protan, Alwitra, Fatra, IKO, Icopal, Decothane and Triflex, which is what allows the manufacturer's system guarantee to sit alongside our own 20-year workmanship warranty. Ask for the documentation with your quote.
Not sure which service you need?
Book a free survey and we'll assess your roof and recommend the right approach — no pressure, no charge.