LF Flat Roofing · Sussex

Warm Roof Insulation Sussex

Done Once. Done Right. All Work Guaranteed.

Upgrading to a warm roof during a re-roof costs a fraction of doing it as a separate job.
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Recognise Any Of These? Warm Roof Insulation Can Fix Them.

Most flat roofs in Sussex were built as cold roofs. The insulation sits below the deck with a ventilation gap above it. In theory this prevents condensation. In practice the gap rarely works as intended, moisture gets trapped and you end up with damp ceilings, mould and rising energy bills.

Cold rooms below the roof

If rooms under your flat roof never warm up properly regardless of how much you heat them. A warm roof upgrade helps by placing insulation above the deck, keeping heat inside the property where it belongs.

Rising energy bills

If heat is escaping through a poorly insulated flat roof on an extension or garage. A warm roof upgrade helps by significantly reducing heat loss through the roof with high-performance PIR insulation.

Draughts and cold spots

If the temperature in the room is uneven, with cold spots that get worse in winter and after rain. A warm roof upgrade helps by creating a continuous insulation layer above the deck with no gaps or thermal bridges.

Condensation on ceilings

If moisture is forming on the underside of the ceiling, leading to staining and mould. A warm roof upgrade helps by eliminating the ventilation gap where moisture gets trapped in traditional cold roof construction.

Mould and damp patches

If there is visible mould growth on ceilings or walls adjacent to the flat roof. A warm roof upgrade helps by removing the conditions that allow condensation to form in the first place, addressing the cause rather than the symptom.

Outdated roof construction

If your roof was built before 2000 with no insulation above the deck. A warm roof upgrade helps by bringing the build-up up to current standards in a single visit, combined with a new weatherproof covering.

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The right solution

Warm Roof Construction: The Right Way To Insulate A Flat Roof

A warm roof places rigid PIR insulation above the structural deck and immediately below the weatherproof membrane. There is no ventilation gap, no moisture trap and no risk of the condensation problems that affect traditional cold roof construction. Heat is conserved within the property, and the roof structure stays warm and dry.

We install warm roof upgrades as part of a re-roofing project, combining new insulation with a new GRP, EPDM or torch-on felt weatherproof layer in a single visit. Tapered insulation boards can also be used to correct drainage falls and eliminate ponding where the roof is flat.

As Icopal-approved contractors, every warm roof installation is completed to building regulations standards with a strict quality process throughout. The result is a thermally efficient, condensation-free roof backed by our 10-year workmanship guarantee.

50-150mm Insulation depth

The thickness specified for your roof is determined on survey to meet current building regulations and maximise thermal performance.

10yr Written guarantee

Every warm roof installation comes with a written workmanship guarantee, backed by LF Flat Roofing directly.

A roofer helping to construct a warm roof.

Icopal-approved installation. Water-tested on completion.

What you get

Why Sussex Homeowners Choose LF Flat Roofing

From the first call to the finished job, here is what you can expect.

Icopal-Approved Contractor

We are trained, tested and certified to install and guarantee Icopal roofing systems to the highest standard.

10-Year Written Guarantee

Every installation comes with a written workmanship guarantee. If something goes wrong due to our work, we come back and fix it.

Honest Advice, Not Upselling

We tell you what your roof actually needs. If a repair will do the job, we will say so rather than push you toward a full replacement.

Free Survey, No Obligation

We visit, assess and give you a fixed written quote. There is no call-out fee and no pressure to proceed.

Tidy, Professional Workmanship

We work cleanly, protect your property throughout and remove all waste on completion. You will not know we were there except for the roof.

Photo records at handover

We document every stage of the installation so you have a permanent record of what was installed, how and when.

How it works

What Happens When You Call LF Flat Roofing?

From the first call to the finished roof; simple, transparent, no surprises.

Step 01

Free survey

One of our team will visit your property and assess if a repair or a replacement is the best solution.

Step 02

Written quote

Fixed price, materials and timescales clearly explained. Sent within 24 hours.
Step 03

Installation

Deck prepared, GRP applied in layers, lap integrity checked, water test on completion.
Step 04

Handover

10-year written guarantee, photo records and aftercare instructions provided.
Real customers

What Sussex homeowners say about LF Flat Roofing

"LF Roofing have replaced the roof lights in my bungalow, they did a brilliant job, I’ve used them before to replace the roof felt and insulate my flat roof bungalow. They are always courteous and professional, clean up after the job and remove the old materials when it’s completed."
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Verified Checkatrade Reviewer
Homeowner, Lancing
"Replaced old flat roof on a converted garage with a warm roof. Cannot fault the workmanship on a great job. Extemely satisfied with end result. Very reasonable price in line with quotes. Would have no hesitation in using again and certainly recommend Liam to anyone thinking of flat roof repairs you will be more than satisfied."
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Verified Checkatrade Reviewer
Homeowner, Brighton
"Liam came recommended to us and we are so glad we asked him to carry out the work. Always professional, polite and was always available to answer any questions I had. I have no hesitation in recommending LF Flat Roofing to family and friends. Highly competitive quote and nothing was ever too much bother."
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Verified Checkatrade Reviewer
Homeowner, Crawley

Frequently asked questions

Find answers to common questions about our flat roofing services.

What is the difference between a warm roof and a cold roof?

In a cold roof, insulation sits below the deck with a ventilation gap above. In a warm roof, insulation sits above the deck directly below the weatherproof membrane. There is no ventilation gap, which eliminates the condensation risk that affects most older flat roofs.

Yes. Rooms below poorly insulated flat roofs can be significantly colder than the rest of the property. A warm roof upgrade addresses this directly by keeping heat inside rather than letting it escape through the roof.

In most cases yes. We add PIR insulation above the existing deck as part of a re-roofing project. The feasibility depends on upstand heights and the condition of the existing deck, which we check on survey.

Where the thermal performance of the roof is being significantly improved, building regulations may apply. We advise on this during the survey and provide the relevant documentation at handover.

Tapered PIR boards are cut at a slight angle so that when laid they create a fall across a flat roof, directing water toward the outlets. This eliminates ponding, which is one of the most common causes of flat roof failure.

The cost depends on the roof size, insulation thickness required and the weatherproof covering chosen. We provide a fixed written quote after the free survey with no hidden extras and no surprises.

Still have a question? Call us on 07793 436 150
Get In Touch

Free survey.
Written quote.
No pressure, ever.

We’ll visit your property, assess the roof and give you an honest recommendation with a fixed written price. If a repair will do the job, we’ll tell you.

Book your free survey

No call-out fee. No obligation. We’ll visit, assess and quote.

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