Flat Roofing in Watford
We carry out flat roof repairs, replacements and new installations across Watford, using proven systems like felt, GRP fibreglass, EPDM rubber and liquid roofing.
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Our flat roofing services in Watford
Our Services
About our flat roofing work in Watford
Watford has a mix of older housing, post-war builds and modern extensions, many of which rely on flat roofs over garages, porches and rear additions. We regularly see issues caused by poor drainage, ageing felt, or systems that were never suited to the roof in the first place. Our approach is simple: assess the roof properly, explain why it has failed, and install or repair it in a way that prevents the same issues coming back.
1,000
Project Completed
97%
Customer Satisfaction
40+
Years of Experience
Flat roofing systems we install
Each system has its place, depending on roof size, shape and drainage
EPDM rubber flat roofing
EPDM rubber roofing is a flexible, long-lasting system that performs well in changing temperatures. It is particularly effective on larger flat roofs where movement can be an issue, and offers excellent resistance to UV and standing water when installed correctly.
GRP fibreglass flat roofing
GRP fibreglass creates a seamless, fully bonded surface that suits garages, extensions and dormers. With no joints and a tough topcoat, it provides a clean finish and strong protection against leaks when properly laid.
Torch-on felt flat roofing
Modern torch-on felt systems are far more reliable than older felt roofs. Installed in multiple layers with reinforced membranes, they offer a cost-effective option for many Watford properties when detailed and finished correctly.
Liquid flat roofing systems
Liquid roofing systems are ideal for flat roofs with complex layouts, multiple penetrations or awkward details. The coating cures into a continuous waterproof layer, reducing weak points and making it well suited to refurbishment work.
Why homeowners in Watford choose us?
Homeowners choose us because we keep things straightforward. We turn up when we say we will, explain the condition of the roof clearly, and recommend work that actually makes sense. Whether it’s a small repair or a full replacement, the focus is on doing the job properly so you’re not dealing with the same problem again.
1,000
Project Completed
97%
Customer Satisfaction
40+
Years of Experience
Trusted Roofing Services Across the
South East
Feedback from homeowners and property managers across Watford who’ve trusted us with their flat roofing work.
Removal of Chimney stack, replacement of roof underlay, guttering and flat roof repair. - Mitchell from Alliance Roofing & Building was the only builder, of many that I had contacted, that climbed a ladder to inspect my flat-roof and to climb into my loft-space to inspect the main roof from the inside. After an extensive review of my property and discussing my options, he emailed me his quotation on the same day. Booking in dates for Alliance & Roofing to commence work was quick and effortless. They arrived on time, completed the work as planned to a professional standard. Provided Photos of work carried out at all stages. I highly recommend Alliance Roofing & Building.
New roof on my bungalow - I recently had the pleasure of working with Alliance Roofing and Building to install a new roof on my bungalow, and I couldn't be more satisfied with the results. From start to finish, the entire process was smooth and professional. Mitchell, who led the project, was exceptional. His expertise and dedication were evident from the moment he arrived. He and his team were not only highly skilled but also incredibly helpful and courteous throughout the entire job. They took the time to answer all my questions
New slate roof - Mitchell and his team installed my new roof and I'm very satisfied. The quality is superb, they were professional, punctual, and communicative. The project finished on time and the site was left spotless.
Guttering repair - Mitchell came to repair my guttering, he was on time, polite, efficient and conscientious. He kept me informed at each stage of the work that was needed.
Roof repairs - Mitchell repointed a chimney and installed a chimney cowl. He also did some cementing work to the roof. Mitchell was very polite and a conscientious worker. He kept me informed throughout the job. Mitchell was able to give me a quote and do the repair work within a few days. I wouldn’t hesitate to recommend Alliance Roofing & Building.
Replacement of flat roof - Mitchell and his team are smart, communicative, skilled, friendly, helpful, trustworthy and reliable. I would highly recommend their roofing services.
Roof tile replacement and chimney repair - Mitchell and his team are reliable, efficient and hard working. We will certainly use them again in the future. Thanks guys
Chimey Removal & Other Minor Repairs - Mitchell was the only roofer who quoted for the job that actually took the time to go up on the roof to inspect the issue, which was appreciated at the time. He fitted us in around other jobs within 2 weeks to get the work done in a timely manner. The work (which included the removal of a chimney stack to below the roof line, repointing the ridge line, and various other patch repairs) appears to have been completed to a good standard (posting days after completion). Mitchell and his team were polite, conscientious and happy to help throughout the job.
Fixed the roof, including all the felting and repaired the chimney. - Good communication throughout. Good work. Very happy with the service.
Roof repair - Great, really friendly and nice team
Tile realignment/repair and felt renewal - Mitchell and his team were excellent. Would definitely recommend Alliance. The team were on time (in fact they were able to begin the job half a day earlier than initially discussed), polite, efficient and kept us informed of progress each day. We could not have asked for a better service.
Roof verge repair. - Mitchell was polite, friendly and knowledgeable. The team were polite and efficient. The work was completed for the price quoted, which was competitive, and in the timeframe advised.
repair of box gutter behind parapet wall - Mitchell undertook a detailed diagnosis of the work required, started the job quite quickly and completed it satisfactorily.
Leak in the roof- Very polite and professional. Job was completed professionally at a very good price. Would highly recommend
New slate roof - Mitchell and his team installed my new roof and I'm very satisfied. The quality is superb, they were professional, punctual, and communicative. The project finished on time and the site was left spotless.
Roof repairs - Mitchell repointed a chimney and installed a chimney cowl. He also did some cementing work to the roof. Mitchell was very polite and a conscientious worker. He kept me informed throughout the job. Mitchell was able to give me a quote and do the repair work within a few days. I wouldn’t hesitate to recommend Alliance Roofing & Building.
Roof tile replacement and chimney repair - Mitchell and his team are reliable, efficient and hard working. We will certainly use them again in the future. Thanks guys
Chimey Removal & Other Minor Repairs - Mitchell was the only roofer who quoted for the job that actually took the time to go up on the roof to inspect the issue, which was appreciated at the time. He fitted us in around other jobs within 2 weeks to get the work done in a timely manner. The work (which included the removal of a chimney stack to below the roof line, repointing the ridge line, and various other patch repairs) appears to have been completed to a good standard (posting days after completion). Mitchell and his team were polite, conscientious and happy to help throughout the job.
Fixed the roof, including all the felting and repaired the chimney. - Good communication throughout. Good work. Very happy with the service.
Roof repair - Great, really friendly and nice team
Tile realignment/repair and felt renewal - Mitchell and his team were excellent. Would definitely recommend Alliance. The team were on time (in fact they were able to begin the job half a day earlier than initially discussed), polite, efficient and kept us informed of progress each day. We could not have asked for a better service.

Every job starts with a proper roof inspection, followed by clear advice on what’s needed and what isn’t.

You’ll receive a straightforward written quote and a realistic timeframe, with no hidden extras or vague promises.
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All work is carried out carefully, then checked before sign-off to make sure the roof is fully watertight and finished properly.
Frequently Asked Questions
If the issue is localised and the structure underneath is sound, a repair may be enough. If leaks keep returning, or the deck and insulation are affected, replacement is usually the better long-term solution.
Leaks are commonly caused by failed joints, damaged edges, blocked outlets, ponding water or ageing materials. Poor installation is also a frequent cause.
There is no single best system. The right choice depends on the roof size, shape, drainage and usage. Felt, GRP, EPDM and liquid systems all work well when matched to the right roof.
Many repairs can be completed in a day. Replacements usually take several days depending on size, access and weather conditions.
Yes. We provide free inspections and written quotes so you know exactly what work is needed and what it will cost.
Some systems can be installed year-round, but conditions matter. If the weather isn’t suitable, we will be upfront rather than rushing a job that won’t last.

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