Expert flat roof installation, repairs and maintenance for homes and businesses, using durable EPDM rubber, GRP fibreglass and felt systems. Free inspection, no call-out charge.
Tell us about your flat roof. We usually reply the same day.
When you call Alliance you get Mitchell and his team, the same people who will actually be up on your roof. No call centre and no subcontractors passing you around, just experienced local roofers who explain what has gone wrong in plain English and put it right properly.
At Alliance Roofing & Building, we provide expert flat roofing solutions, offering high-quality installations, repairs and maintenance for both residential and commercial properties. Whether you need a new flat roof, a re-roof, or repairs to an existing one, we deliver a durable, watertight finish built to withstand the elements.
Using premium materials such as EPDM rubber, GRP fibreglass and felt roofing, we deliver flat roofs that are not only long-lasting but also low maintenance. Our team serves Buckinghamshire, Hertfordshire, Berkshire, Surrey and London, providing tailored solutions for residential, commercial and industrial properties, from garage roofs and extensions to large commercial flat roofs.
High-quality flat roofing designed for durability and efficiency, ideal for extensions, garages and dormers.
Fixing leaks, cracks and damage to restore your roof's integrity and keep your property watertight.
Upgrading existing flat roofs with new, weather-resistant materials for a longer lifespan.
Expert installation of every major flat roofing system to suit your property and budget.
A seamless, single-piece rubber membrane that resists UV and weather, with a long service life and minimal maintenance.
A tough, seamless fibreglass system with a hard-wearing finish, ideal for balconies, dormers and high-traffic flat roofs.
A proven, cost-effective multi-layer system that gives a reliable, watertight finish when professionally installed.
Every flat roof is different. Here is how the three main systems compare, so you know exactly what you are paying for.
| System | Typical lifespan | Best for | Why homeowners choose it |
|---|---|---|---|
| EPDM rubber | 25-30 years | Extensions, garages, larger flat roofs | One seamless rubber sheet with very few joints, so very few places to leak. Low maintenance and stays flexible in cold weather. |
| GRP fibreglass | 25-30 years | Balconies, dormers, walk-on roofs | A hard, seamless finish that handles foot traffic and can be laid in a colour. Ideal where the roof is on show or walked on. |
| Felt (torch-on) | 10-20 years | Budget re-roofs, sheds, outbuildings | The most cost-effective option. Modern three-layer torch-on felt is far tougher than the old pour-and-roll felt it replaced. |
Not sure which is right for your property? We inspect your existing roof, explain the options in plain English and recommend the system that gives you the best value over its lifetime, never just the most expensive one.
A flat roof is priced on its size, the system you choose, access to the roof, and whether the old covering or any rotten timber needs removing first. As a rough guide for the South East:
| Job | Typical system | Indicative guide price |
|---|---|---|
| Single garage roof (approx. 15m²) | Felt or EPDM | £1,500 - £3,000 |
| Rear extension (approx. 20-30m²) | EPDM or GRP | £2,500 - £5,500 |
| Dormer or balcony | GRP fibreglass | £1,800 - £4,000 |
| Larger or commercial flat roof | EPDM or felt | Priced on survey |
Guide figures for illustration only. Your written quote is free, fixed and based on a proper inspection, with no call-out charge and no obligation.
Want an exact figure for your roof? Send us a few details or call 01753 316 053 and we will usually have a price back to you the same day.
A flat roof rarely fails overnight. Spotting these early usually means a straightforward repair rather than a full replacement:
We will tell you honestly whether a targeted repair will see you right or whether a re-roof is the better long-term value. No scare tactics, no upselling, just a straight answer with photos.
We check the deck, the falls and the drainage, take photos and talk you through what we find. No call-out charge.
A fixed price with the system, timescale and guarantee spelled out, usually back to you the same day.
We remove the old covering, replace any rotten timber and make sure the roof drains properly before anything new goes down.
Your new EPDM, GRP or felt system is laid, dressed into every detail, and finished with photos and your 10-year workmanship guarantee.
We install and repair flat roofs right across our patch. A few of the areas we cover:
★★★★★ 103 verified Checkatrade reviews
"Replacement of a flat roof. Mitchell and his team are smart, communicative, skilled, friendly, helpful, trustworthy and reliable. I would highly recommend their roofing services."
"Mitchell was the only builder of many I contacted who actually climbed a ladder to inspect my flat roof and got into the loft. Quote the same day, work to a professional standard, photos at every stage."
"Good communication throughout. Good work. Very happy with the service. They fixed the roof including all the felting and repaired the chimney."
Free inspection, no call-out charge, honest written quote, usually the same day.
