Wigan at a glance
- Postcode districts
- WN1, WN2, WN3, WN4, WN5, WN6, WN7
- Population
- about 175,405 (GeoNames)
- Council area
- Wigan Council
- Building approval
- Wigan Council building control, or a registered building control approver
- Nearest main town
- St Helens, about 8 miles
- Guide price region
- North West (−5% on West Midlands rates)
Why choose a green roof in Wigan?
In a place like Wigan, many people look out over a flat extension or garage roof from upstairs. Grey felt or rubber isn't much of a view, and a sedum roof turns it into something green that changes colour through the seasons and flowers in summer.
In and around Wigan, flat roofs are typically found on shops with flat-roofed rear stores below flats, and on 1960s and 1970s link-detached houses with flat-roofed garages and porches. The North West is one of England's wetter regions, averaging roughly 1,290 mm of rain a year, so falls, outlets and well-detailed upstands matter more than the membrane colour.
How much does a green roof cost in Wigan?
Guide price in Wigan: £4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, including VAT at North West rates. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM with sedum green roof | £4,200–£7,700 |
| Extension (20 m²), EPDM, new deck + insulation | £2,650–£4,650 |
Can my flat roof take the weight of a green roof?
Not every roof can, which is why we check the structure before quoting. A sedum roof is light compared with an intensive garden, but its growing medium holds water, and a saturated build-up adds significant weight to the roof.
We look at the joist sizes, spans and spacing, the condition of the deck and what the roof sits on. On a recently built extension with generously sized joists, an extensive green roof may be straightforward. On an older garage or a roof with undersized or rotten timbers, the structure may need strengthening, or a structural engineer's calculation may be needed before we can go ahead.
In England, a new roof covering that adds 15% or more to the weight of the roof triggers building control approval, and a green roof will often fall into that category. We handle building control where it is needed. The building regulations page covers the approval routes in each nation.
What's included?
- Structural check of joists, deck and supports
- Pre-grown sedum blankets laid and watered in
- Root-resistant membrane or separate root barrier
- Warm or inverted build-up to suit the roof
Building regulations in England
Replacing more than half of a flat roof over a heated room usually counts as renovating a thermal element, so the roof is insulated to around 0.16 W/m²K where that's technically and economically feasible, and the work is notified to building control: the council or a registered building control approver, unless a registered competent person self-certifies it. A roof on a new extension is built to 0.15 W/m²K. Patch repairs, and most unheated detached garages, don't trigger the upgrade. Structural changes, or a new covering that adds 15% or more to the roof's weight, also need approval. More on the rules.
Which nearby areas do we also cover?
- Hindley · 2 mi
- Ashton in Makerfield · 4 mi
- Westhoughton · 5 mi
- Golborne · 5 mi
- Horwich · 5 mi
- Haydock · 6 mi
Green and sedum roofs in Wigan: questions
Do you cover Wigan?
Yes. Wigan is part of our Greater Manchester coverage, including postcode districts WN1, WN2, WN3, WN4, WN5, WN6 and 1 more. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building regulations for a flat roof in Wigan?
Where the work needs approval it goes to Wigan Council building control, or a registered building control approver. We tell you at the survey whether your job needs it and deal with the paperwork as part of the quote.
How much does a green roof cost in Wigan?
£4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, at North West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
What happens if a green roof needs repairing?
The green layers are lifted around the problem area, the membrane is repaired, and the layers are relaid. Building on a sound, long-life membrane in the first place keeps that to a minimum.
Can you put a sedum roof on a garage?
Often, yes, if the structure is strong enough. Many older garage roofs have light timbers, so a structural check comes first and strengthening may be needed.