Services / Flat Roof Protection

Flat roof protection in London & surrounding counties

Perlini specialises in seamless flat roofing across London and the surrounding counties using the Ultraflex system, a fully bonded, cold-applied waterproofing solution that’s rainproof in 30 minutes and guaranteed for 20 years.

Rainproof in 30 minutes
Safe installation
Overlays most existing roofs
20-year guarantee

Instant Estimate

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.

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
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
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. We may also recommend a survey to be carried out. View a sample flat roof survey report.
3
Installation
Our trained team prepares the surface and installs the Ultraflex system, delivering a seamless, fully bonded waterproof finish built to last.
4
Sign-off & 20 Year Guarantee
We inspect the roof, hand over your 20-year guarantee documentation, and leave the property spotless.

Also for commercial buildings

Commercial flat roofing

The same Ultraflex system, specified for offices, apartment blocks, schools and public-sector buildings. Works are phased around occupied buildings so each section is left watertight at the end of the working day, with method statements, insurance certificates and a single point of contact for facilities teams.

See our commercial flat roofing service

How Ultraflex compares

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

Criteria	Ultraflex	GRP	EPDM	Asphalt	FeltTorch-on Felt
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

New flat roof installations with Ultraflex typically work out far more cost-effective than traditional strip-and-replace builds. Use our instant estimator for a personalised price for your project.

Ultraflex FAQs

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

A domestic extension or garage roof is usually two to four days from set up to handover, including preparation and detailing. Larger commercial roofs are phased in sections, with each section left fully watertight at the end of each working day.

Replacing an existing flat roof like for like does not normally need planning permission, though it does need to meet current Building Regulations for thermal performance where the roof is over a heated space. New extensions, roof terraces and any work on a listed building or in a conservation area are a different matter and should be checked with your local authority.

Where the roof covers a heated room, the build-up must meet the current Building Regulations U-value requirement, which in practice means a substantial thickness of rigid insulation as a warm roof above the deck. We specify the correct thickness for your build-up and confirm it in the quotation.

In most conditions, yes. The resin can be applied down to around freezing on the main roof area and slightly below on details, and it is rainproof in as little as thirty minutes. That makes the installation programme far more predictable through a British autumn and winter than torch-on felt or fibreglass.

Wherever the deck and insulation are dry and sound, yes, and it is usually the option we recommend. Overlaying removes strip-out and disposal costs and means the building is never left open. Where the insulation is already saturated we will identify it at survey and price for cutting out those areas first.

A twenty-year guarantee covering both materials and workmanship, issued on completion after our own final inspection, along with a photographic record of the detailing carried out during the installation.

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.