- Price per m²
- £75–£132
- Typical life
- 30–60 years
- Manufacturer guarantees
- 15-year material, up to 25-year system guarantees
- 30 m² roof
- £3,050–£5,500
County Down at a glance
- Largest towns
- Bangor, Newtownards, Newry, Banbridge
- Postcode areas
- BT
- Building control
- Ards and North Down Borough Council, Newry, Mourne and Down District Council, Armagh City, Banbridge and Craigavon Borough Council and 1 other council
- Neighbouring areas
- Belfast · County Antrim · County Armagh · County Tyrone
- Guide price region
- Northern Ireland (−12% on West Midlands rates)
How much does mastic asphalt roofing cost in County Down?
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 |
|---|---|
| Mastic asphalt roof (30 m²), scaffold | £3,050–£5,500 |
| Localised patch repair | £130–£440 |
| 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 Down?
Flat roofs in County Down sit on lock-up garage blocks on estates, 1960s and 1970s link-detached houses with flat-roofed garages and porches and terraced streets with flat-roofed rear kitchens and bathrooms. 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 Down the application goes to Ards and North Down Borough Council, Newry, Mourne and Down District Council, Armagh City, Banbridge and Craigavon Borough Council and 1 other council. More on the rules.
Should an old asphalt roof be repaired, overlaid or replaced, especially on a heritage building?
If the asphalt is sound apart from local cracks or blisters, repair it; if it is crazed and tired but dry and well bonded, consider an overlay; if it is leaking widely, sitting on a wet or failing deck, or full of trapped moisture, replace it. A survey, sometimes with a leak trace, tells you which applies.
- Repairs: blisters are cut out, cracks opened up and fresh asphalt worked in by a specialist, so the repair fuses with the existing roof.
- Overlay: a compatible system, often a reinforced liquid membrane, is bonded over the old asphalt after cleaning and priming. This keeps the old asphalt as a solid base and avoids heavy strip-out.
- Replacement: the old asphalt is broken out and the roof rebuilt, either in new asphalt or in another system the structure can carry, with insulation where required.
On heritage and older buildings, matching the original material and detailing often matters as much as waterproofing. New asphalt skirtings and aprons can follow the existing lines, and any change of material on a listed building should be agreed with the conservation officer before work starts.
Asphalt work is a specialist trade. It needs mixers or boilers on site, trained asphalters and strict hot-works control, so we plan these jobs around access, the building's occupants and the weather.
Which towns in County Down do we cover?
- Bangor
- Newtownards
- Newry
- Banbridge
- Dundonald
- Holywood
- Downpatrick
- Comber
- Carryduff
- Warrenpoint
- Newcastle
- Donaghadee
Mastic asphalt roofing in County Down: questions
Which towns in County Down do you cover?
All of County Down. 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 mastic asphalt roofing cost in County Down?
£3,050–£5,500 for a 30 m² mastic asphalt roof including scaffold, at Northern Ireland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Which postcode areas do you cover in County Down?
All of County Down, including the BT postcode areas. Send your full postcode and we'll confirm.
Is mastic asphalt suitable for a balcony or terrace?
Yes, asphalt is traditionally used on terraces and walkways because it takes foot traffic well, often with paving on top. A new balcony or terrace generally needs planning permission, so check before converting a roof.
Can you put felt or rubber over an asphalt roof?
Sometimes, if the asphalt is dry, well bonded and sound, using a compatible system and primer. Liquid membranes are a common choice because they bond well to cleaned asphalt.
Why are mastic asphalt roofs painted silver or white?
The reflective coating keeps the asphalt cooler in sun, reducing softening and slowing the surface ageing that leads to crazing. It usually needs renewing every few years as part of maintenance.
Everything about mastic asphalt roofing → · All flat roofing in County Down →