- Guide price
- £2,450–£4,300
- Survey
- Free for new and replacement roofs
- Quote
- Fixed, in writing
- Coverage
- England, Wales, Scotland, NI
County Antrim at a glance
- Largest towns
- Lisburn, Newtownabbey, Carrickfergus, Ballymena
- Postcode areas
- BT
- Building control
- Lisburn and Castlereagh City Council, Antrim and Newtownabbey Borough Council, Mid and East Antrim Borough Council and 1 other council
- Neighbouring areas
- Belfast · County Down · County Armagh · County Londonderry
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
How much does a flat roof replacement cost in County Antrim?
Guide prices including VAT at Northern Ireland rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,450–£4,300 |
| Single garage (18 m²), torch-on felt | £1,350–£2,300 |
| Extension (20 m²), GRP, new deck + insulation | £2,650–£4,750 |
| Single garage (18 m²), EPDM rubber | £1,400–£2,450 |
Which flat roofs are common in County Antrim?
Flat roofs in County Antrim sit on lock-up garage blocks on estates, 1960s and 1970s link-detached houses with flat-roofed garages and porches and low-rise post-war blocks of flats. Northern Ireland averages roughly 1,150 mm of rain a year, spread over many wet days, so a roof that sheds water quickly to clear outlets lasts far longer than one that holds puddles. Approximate 1991–2020 regional averages based on Met Office data.
Building control in Northern Ireland
In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where feasible. In County Antrim the application goes to Lisburn and Castlereagh City Council, Antrim and Newtownabbey Borough Council, Mid and East Antrim Borough Council and 1 other council. More on the rules.
How long does it take to replace a flat roof?
A garage or single-storey extension roof is usually stripped and re-covered in one to three working days; larger, higher or more detailed roofs take longer. Weather sets the pace, because the deck must be dry before insulation and membrane go down.
We strip only as much as can be made weathertight that day, so the roof is never left open overnight. Expect noise and some vibration during the strip, a skip on the drive (or on the road with a permit) and ladders or a tower against the house. Rooms below stay usable, though it helps to clear shelves near the ceiling. Resin systems such as GRP smell strongly while they cure, so keep nearby windows closed that day. Two-storey roofs need scaffold, which goes up before we start and comes down after sign-off.
Which towns in County Antrim do we cover?
Flat roof replacement in County Antrim: questions
Which towns in County Antrim do you cover?
All of County Antrim. The main towns have their own pages below, and if yours isn't listed we still cover it: send your postcode and we'll confirm.
How much does a flat roof replacement cost in County Antrim?
£2,450–£4,300 for a 20 m² extension roof in EPDM with a new deck and insulation, at Northern Ireland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which council handles building control for a flat roof in County Antrim?
It depends on where the roof is: in County Antrim that's Lisburn and Castlereagh City Council, Antrim and Newtownabbey Borough Council, Mid and East Antrim Borough Council and 1 other council. In Northern Ireland, renovating or replacing a roof over a heated room usually means meeting Technical Booklet F1, and building control should be contacted before work starts. We confirm which applies at the survey.
Will a replacement make my roof higher?
Usually a little, if insulation is added above the deck. We check door thresholds, window sills, upstands and wall flashings at survey so the new level works.
What guarantees come with a replacement roof?
Every re-roof comes with a written workmanship guarantee, with the length set out in your quote. Manufacturer material guarantees are available on many systems and we register them for you where the system allows; ask about insurance-backed options too.
Can you replace just part of a flat roof?
Sometimes, if the rest is sound and dry. Renovating more than half of a roof over a heated room usually brings the whole roof under the insulation rules, so a full replacement can make more sense.
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