A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
We handle a new flat roof as a managed project across County Antrim: one contract, one contact, and trades working to an agreed specification. Coverage includes Belfast, Lisburn, Newtownabbey and Carrickfergus and their surroundings. In Northern Ireland the consent rules have their own details, which we check for you. Typical prices in Northern Ireland fall within £1,700–£3,900, VAT included, and are fixed in writing after a survey.
- Guide price
- £1,700–£3,900 inc VAT
- Time on site
- 1–3 days for most roofs
- Planning rules
- Northern Ireland
- Price level
- About 14% below the national guide
- Towns listed
- 7
- Survey
- Free, with a written quote
How much does a new flat roof cost in County Antrim?
The table below shows guide prices for a new flat roof in County Antrim. They are based on rates in Northern Ireland, which run about 14% below the national guide, giving an overall range of £1,700–£3,900. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in County Antrim |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £700–£1,700 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £1,700–£3,900 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £3,400–£7,700 |
The main things that change the figure:
- Roof area and access to the roof
- Covering system: EPDM, GRP or torch-on felt
- Insulation upgrades and changes to roof height at edges
- Number of rooflights, pipes and upstands to detail
What’s included?
- Survey of the covering, deck, falls, upstands and drainage
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
- Rooflights refitted or replaced where required
Homes in County Antrim
Belfast has long rows of red-brick Victorian terraces, Edwardian villas in the north and south of the city and large post-war estates, while towns such as Ballymena, Antrim, Larne and Carrickfergus mix terraces, semis and newer developments. Dark basalt appears in older rural buildings, and pebbledash or roughcast is a very common finish.
Terraces suit loft conversions and rear extensions, and many need window and roof renewal. Pebbledashed homes commonly need re-rendering, and detached rural houses often take extensions, porches and driveways.
The north coast and glens are exposed to strong winds, salt and frequent rain, which affects render, roofline and outdoor work.
Do you need permission in County Antrim?
County Antrim is in Northern Ireland, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
In Northern Ireland, re-roofing with similar materials does not usually need planning permission outside listed buildings and conservation areas.
Significant re-roofing should be checked with building control under the Building Regulations (Northern Ireland). Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Free site survey
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Your fixed price
After the survey we send a quote for a new flat roof that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Getting ready
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
The work itself
Our trades complete a new flat roof while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
How we work
Questions about a new flat roof in County Antrim
Which postcodes in County Antrim do you cover?
We cover BT1, BT17, BT36 and BT38, along with the rest of County Antrim. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
How much does a new flat roof cost?
Re-covering a typical 15–25m² extension or garage roof costs £1,700–£3,900. As a guide, allow around £75–£170 per square metre plus fixed costs for stripping, waste and access, with torch-on felt at the lower end and GRP or EPDM with new decking or insulation at the top. Small dormer and porch roofs cost less overall but more per square metre. We confirm a fixed price after the survey.
How long does a flat roof replacement take?
Replacing a typical extension or garage flat roof usually takes one to three days. Stripping and any deck repairs come first, then insulation where agreed, the new membrane and the trims and outlets. GRP needs dry weather and time to cure, and we plan around the forecast. Larger roofs or roofs with many rooflights take longer. We confirm timing with your quote.
Should I insulate my flat roof when it is replaced?
Replacing a flat roof is the most cost-effective time to add insulation, because the covering is already off. A warm roof, with insulation laid above the deck, keeps the structure warm and reduces condensation risk. Building regulations may require insulation when a large part of the roof is renewed. It raises the roof height slightly, which affects trims and upstands.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Towns in County Antrim
Homes in all of the following County Antrim towns can get a written quote for a new flat roof. Open a town page to see prices and the postcodes we cover.