- Price per m²
- £79–£128
- Typical life
- 25–35+ years
- Manufacturer guarantees
- 20–25 year guarantees on specified systems
- Typical garage roof
- £1,800–£2,950
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)
How much does a single-ply roof cost in County Londonderry?
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 |
|---|---|
| Commercial roof (100 m²), single-ply + insulation | £11,650–£19,150 |
| Single garage (18 m²), single-ply | £1,800–£2,950 |
| Single garage (18 m²), EPDM rubber | £1,400–£2,450 |
| Extension (20 m²), EPDM, new deck + insulation | £2,450–£4,300 |
Which flat roofs are common in County Londonderry?
Flat roofs in County Londonderry sit on 1960s and 1970s link-detached houses with flat-roofed garages and porches, lock-up garage blocks on estates and bungalows with flat-roofed side extensions and dormers. 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 Londonderry the application goes to Derry City and Strabane District Council, Causeway Coast and Glens Borough Council and Mid Ulster District Council. More on the rules.
How long does a single-ply roof last, and what guarantee comes with it?
A well-installed single-ply roof typically lasts 25 to 35 years or more. Its life depends mostly on the quality of the welds, the fixing pattern, protection from foot traffic and keeping outlets clear.
Signs of trouble on an older single-ply roof include seams lifting at the edges, shrinkage pulling at upstands and corners, punctures near plant, and loose fixings under the membrane on windy sites.
Manufacturer guarantees are available on many specified single-ply systems, and they often depend on a registered build-up, an inspection and sometimes an approved installer. Where the system allows, we complete that registration on your behalf. On every re-roof you also receive our written workmanship guarantee, with the length set out in the quote, and you can ask about insurance-backed options. See the guarantees guide and maintenance guide for more.
What insulation and approvals does a single-ply re-roof need?
On a heated building, a full single-ply re-roof usually triggers the thermal-element rules, so insulation should be brought towards the renovation standard where feasible. In England that is 0.18 W/m²K for non-domestic and 0.16 W/m²K for domestic roofs, with Wales and Northern Ireland setting their own figures; Scottish roofs follow Section 6 of the building standards, and the council confirms whether a building warrant is required.
Single-ply suits a warm roof well, and tapered insulation can correct poor falls at the same time. A thicker build-up raises the roof, so we check upstand heights, door thresholds and rooflight kerbs at survey. Near boundaries, the external fire classification of the tested build-up can matter. We handle building control or building standards where needed; see the building regulations page.
Which towns in County Londonderry do we cover?
Single-ply membrane roofing in County Londonderry: questions
Which towns in County Londonderry do you cover?
All of County Londonderry. 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 single-ply roof cost in County Londonderry?
£11,650–£19,150 for a 100 m² commercial roof in single-ply with 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 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.
Can single-ply be used on a house?
Yes. It can be used on garages, extensions and dormers, usually adhered rather than mechanically fixed. On small domestic roofs, though, EPDM or GRP is often more economical.
Can single-ply roofing be laid over an existing roof?
Sometimes, if the existing roof and deck are dry and sound, often with a separation layer or new insulation on top. Wet insulation or a damaged deck means stripping first.
Is single-ply roofing noisy in the rain?
No more than other flat roofs. Noise depends far more on the deck and insulation than on the membrane, and an insulated warm roof dampens rain noise well.
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