County Londonderry at a glance
- Largest towns
- Derry/Londonderry, Coleraine, Limavady, Magherafelt
- Postcode areas
- BT
- Building control
- Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District Council
- Neighbouring areas
- County Tyrone · County Antrim · County Armagh · Belfast
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
Which towns in County Londonderry do we cover?
5 towns and cities have their own page; we cover everywhere in between too.
What does a flat roof cost in County Londonderry?
Guide prices at Northern Ireland rates, including VAT. The fixed price comes after a survey.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), felt, new deck + insulation | £2,400–£4,100 |
| Porch or bay (4 m²), EPDM | £650–£1,100 |
| Condition survey and leak investigation | £130–£260 |
| Single garage (18 m²), liquid-applied | £1,800–£2,850 |
| Balcony (12 m²), liquid-applied, scaffold | £1,650–£2,850 |
| Extension (20 m²), EPDM, new deck + insulation | £2,450–£4,300 |
Which flat roofs are common in County Londonderry?
Weather matters on a flat roof. 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. Across County Londonderry, flat roofs are typically found on shops with flat-roofed rear stores below flats, terraced streets with flat-roofed rear kitchens and bathrooms and 1930s semis with flat-roofed garages and kitchen extensions. Approximate 1991–2020 regional averages based on Met Office data.
Which flat roof jobs do we take on in County Londonderry?
Flat roof replacement
A sensible moment to replace a flat roof in County Londonderry is when other work is planned on the house, such as a kitchen refit below, new windows or a loft conversion. Doing the roof first protects the new work, and it is the natural time to upgrade insulation to the level the regulations expect for a renovated roof.
Garage roofs
Garage roofs in County Londonderry are often replaced when the deck gives way. Chipboard decks swell and soften once they get wet, and you may see sagging between joists or feel the roof flex underfoot. Replacing the deck and covering together is usually more economical than repeated repairs.
Torch-on felt roofing
Where a flat roof in County Londonderry already has a felt covering and the building owner wants like-for-like, torch-on is the natural replacement. The old roof is stripped, the deck checked and the new layers laid, often with warm-roof insulation added when the space below is heated.
Building control in Northern Ireland
In Northern Ireland, Technical Booklet F1 sets roof insulation at 0.18 W/m²K when a roof over a heated room is renovated or newly built, where that's feasible. The district council's building control should be contacted before work starts, and we prepare the details it asks for. More on the rules.
Which services do we offer in County Londonderry?
- Rooflights in flat roofs
- Flat roof repairs
- Mastic asphalt roofing
- Extension and kitchen roofs
- Flat roof surveys and leak tracing
- Flats, HMOs and block roofs
- Garage roofs
- Commercial flat roofing
- Emergency leak repairs
- Flat roof replacement
- Edge trims, outlets and drainage
- Liquid-applied roofing
- Dormer roofs
- Warm roof insulation upgrades
- Single-ply membrane roofing
- Porch, bay and canopy roofs
- EPDM rubber roofing
- Balconies and roof terraces
- GRP fibreglass roofing
- Torch-on felt roofing
- Green and sedum roofs
Flat roofing in County Londonderry: questions
Do you cover all of County Londonderry?
Yes. We cover the whole of County Londonderry, including Derry/Londonderry, Coleraine, Limavady, Magherafelt. If your town isn't listed, send your postcode and we'll confirm.
Which council handles building control for a flat roof in County Londonderry?
It depends on where the roof is: in County Londonderry that's Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District 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.
How much is a new flat roof in County Londonderry?
A typical 18 m² EPDM garage roof is £1,400–£2,450 and a 20 m² insulated GRP extension roof is £2,650–£4,750, at Northern Ireland guide rates including VAT.
How soon can you survey a roof in County Londonderry?
It depends on the time of year and where the roof is; we give you a date when you get in touch, and leaks are prioritised.