Lee FlecknellEmergency roof repairs, rental property · August 2026
Highly recommend this company carried out some emergency roof repairs on one of my properties would use again.
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Flat roofing
Flat roofing in EPDM rubber, GRP fibreglass and felt
Flat roofing for garages, extensions, dormers and balconies, laid in EPDM rubber, GRP fibreglass or torch-on felt. Best Top Roofing strips the failed roof, replaces any soft decking, and finishes with clean trims and a fall that sends water off the roof, not into the room below. Free fixed written quotes across Hertfordshire and Northamptonshire.
Flat roofs fail from underneath as often as from the top. Water gets in through a split in the felt, soaks into a chipboard or plywood deck, and the deck swells, sags and starts to rot. Ponding water then sits in the dip and finds the next weak spot. Laying a new covering over a soft deck gives you a roof that feels spongy underfoot and fails early, so every flat roof we lay goes onto new decking wherever the old deck is not sound.
We fit three systems and help you choose. EPDM rubber is a single sheet with no joints across the roof, ideal for garages and extensions and very long lasting. GRP fibreglass is laid wet and cures into a hard, joint-free surface that you can walk on, which makes it the choice for balconies and roofs with lots of detail. Torch-on felt is the traditional built-up system, quick to lay and the most economical, and modern felts last far longer than the old sheds and garages suggest.
Whichever system goes on, the details decide how long the roof lasts: the fall, the edge trims, the upstands against walls and the outlet into the gutter. We get those right on every roof, including one of our Google reviewers' new flat roof, done "exactly how I wanted it".
When you call, you speak to the familyBest Top Roofing is family-run. The family that answers the phone and gives you the quote is the family that turns up and does the job.
What is included
- Old covering stripped and the deck checked board by board
- Soft, rotten or delaminated decking replaced with new boards
- Firrings added where the roof needs a better fall
- EPDM rubber, GRP fibreglass or torch-on felt laid to the manufacturer's spec
- New edge trims, drip details and gutter outlets
- Upstands and flashings where the roof meets walls and windows
- Rooflights and roof lanterns fitted or re-sealed
- Site cleared and old materials removed
Signs you need this
- Puddles still sitting on the roof days after rain
- Blisters, cracks or bare patches in the felt
- A soft or bouncy feel when you step on it
- Damp or mould on the ceiling of the extension below
- Moss and plants growing across the surface
How it works
Survey and system choice
We check the deck, the fall and the details and recommend EPDM, GRP or felt for your roof.
Fixed written price
The system, the decking and the trims set out in writing.
Strip and re-deck
Old roof off, decking replaced where needed, falls corrected.
New roof and trims
The new covering laid, edges and outlets finished, the site cleared.
A flat roof is only as good as the deck under it and the detail at the edges. We do not lay a new roof over an old problem.
Flat roofs: your questions answered
Which is best, EPDM, GRP or felt?
EPDM suits most garages and extensions and lasts a very long time. GRP is best where the roof is walked on or has lots of corners and upstands. Felt is the most economical. Our EPDM vs GRP guide compares them side by side.
How long does a flat roof replacement take?
A single garage or small extension is usually one to two days. Larger extensions, balconies and roofs that need full re-decking take longer, and the timing is in the quote.
Can you lay a new flat roof over the old one?
Only when the existing deck is completely sound and dry, which is rare on a roof that is leaking. In most cases stripping and re-decking is the job that lasts.
Can you fit a roof lantern or rooflight?
Yes. It is the best time to add one, because the roof is open and the upstand can be built into the new covering properly.
Do flat roofs need maintenance?
Keep outlets and gutters clear of leaves and moss, and have a look after storms. A well-laid EPDM or GRP roof needs very little else.
Flat roofs by area
Related services
Reviews
What customers say on Google
Dannie SmithQuoted the next day · June 2026
Thomas came and gave me a quote next day, very professional and clean work was carried out. I will be using best top roofing for all my projects going forward and would highly recommend them.
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R Vidya RLeaking felt roof repaired · September 2026
thanks to Thomas for fixing our roof. It was pleasure working with you. I feel confident that the water leak is accessed from all points and all problem addressed
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Lee SextonNew flat roof · April 2026
I needed a new flat roofing doing and this amazing company did it exactly how I wanted it. Highly recommended. Friendly and polite. Would use and again and tell all my friends and family.
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Mahmoud Al SuwwanRoof problem fixed · August 2026
We had a problem in our roof we called this company and they solved the problem so happy and satisfied. I really highly recommend if anyone needs roofing work done if I ever need a roofer again hopefully we don't if I ever did I will always use this company again, thank you so much, guys.
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Lisa DunneBlocked gutters cleared · April 2026
Cleaned out our gutters as were blocked and overflowing. Very happy with the job done. Thank you very much!
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Ligita KaledaiteChosen over other quotes · July 2026
Very friendly. Had couple of Quotes from other companys And this was the best company for it.
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Sally MaskellRoofing work by Thomas · June 2026
Very impressed with the work that Thomas has done. Definitely recommend.
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Scarlet BullRoofing work · August 2026
Professional, good quality work! Recommended.
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Checkatrade customerBalcony roof installation · August 2026
Fantastic, professional and polite throughout the job.
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10 year
re-roof
guarantee
Our guarantee
re-roof
guarantee
Every new re-roof guaranteed for 10 years, in writing
When we replace your roof, our workmanship is guaranteed for 10 years from the day we finish, and the membrane, tiles and slates carry their manufacturers' guarantees on top. Repairs and flat roofs are guaranteed too, with the terms for your job written on your quote. We are fully insured.
Covered
- Our workmanship on every new re-roof for 10 years
- Lead, flashings, ridges and verges we fit
- Flat roofs laid to the system's specification
- Repairs, with the terms written on the quote
On top
- Tile and slate manufacturer guarantees
- Membrane and flat roof system guarantees
- Photos of the finished job
- The same family to call if anything is wrong
Not covered
- Storm or accidental damage after completion
- Work altered or added by someone else
- Parts of the roof we did not work on
- Gutters left to block and overflow
The guarantee for your job is written on your quote before you agree to anything. Read the full guarantee.
Talk to us about flat roofs
Ring or send the form. We come out, look at the roof, show you what is needed and give you a fixed written price. No pressure and no hidden extras.