Flat roof cost in St Albans
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What could move the final price
An estimate from 2026 roofing prices for our area, not a quote. Your fixed written quote follows a free survey, and the price we quote is the price you pay.
Flat roof cost in St Albans is £1,500 to £6,300 in 2026, from a felt garage roof to a large extension in GRP fibreglass. The price is set by the size of the roof and the covering. Build yours in the builder above for your own range.
Flat roof prices in St Albans by size and covering
| Roof | Felt (torch-on) | EPDM rubber | GRP fibreglass |
|---|---|---|---|
| Single garage (about 18m²) | £1,500 to £2,100 | £1,700 to £2,500 | £2,050 to £2,850 |
| Extension roof (about 25m²) | £2,100 to £2,900 | £2,350 to £3,450 | £2,850 to £3,950 |
| Large extension or dormer (about 40m²) | £3,350 to £4,650 | £3,750 to £5,500 | £4,600 to £6,300 |
Ranges are 2026 prices for St Albans, built from published UK roofing costs with a regional adjustment, rounded to the nearest £50. Your fixed written quote follows a free survey.
Straight answers
What sets the cost of a flat roof
Size
A single garage is about 18m², a single-storey extension about 25m². Price per m² does the rest.
Covering
Torch-on felt is £80 to £110 per m², EPDM rubber £90 to £130 and GRP fibreglass £110 to £150.
The deck underneath
A soft or rotten deck has to be replaced before the new covering goes on. We check it and tell you first.
Roof lights and upstands
Each roof light, wall and edge takes detailing. That is where cheap flat roofs leak, so we price it properly.
Every flat roof from Best Top Roofing includes
- The old covering stripped and taken away
- The deck checked and made good
- Your choice of felt, EPDM or GRP with proper edge trims and upstands
- A fixed written price and a workmanship guarantee
Real customers
What St Albans homeowners say
"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."
Verified Google review"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."
Verified Google review"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."
Verified Google reviewGood questions
Roofing prices, answered
How much does a flat roof cost in St Albans?
How much is a new garage roof?
Which is best, EPDM or GRP?
How long does a flat roof take?
More St Albans roofing prices
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