Leigh at a glance
- Postcode districts
- WN7
- Population
- about 43,626 (GeoNames)
- Council area
- Wigan Council
- Building approval
- Wigan Council building control, or a registered building control approver
- Nearest main town
- Wigan, about 6 miles
- Guide price region
- North West (−5% on West Midlands rates)
Why upgrade to a warm roof in Leigh?
In a place like Leigh, homeowners usually think about insulation when the roof covering is worn out. That is the right moment, because the thermal rules normally apply to a replacement over a heated room, and adding insulation then costs far less than doing it separately later.
Leigh's flat roofs are mostly on shops with flat-roofed rear stores below flats, with plenty on newer estates where the first extension roofs are now being replaced too. 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 warm roof upgrade cost in Leigh?
For Leigh we use North West rates: £2,650–£4,650 is the guide for a 20 m² extension roof in EPDM with a new deck and insulation, VAT included. The fixed price comes after a free survey for new and replacement roofs.
| Job | Guide price inc VAT |
|---|---|
| Extension (20 m²), EPDM, new deck + insulation | £2,650–£4,650 |
| Extension (20 m²), EPDM with sedum green roof | £4,200–£7,700 |
Can a cold flat roof be converted to a warm roof?
Yes, and it is the usual approach when an older cold roof is re-covered. The old covering is stripped, the deck is checked and replaced where needed, and the vapour control layer, insulation and new waterproofing go on top.
The existing insulation between the joists is assessed at the same time. Leaving it in place can create a cold, unventilated gap that traps moisture, so it is often removed or the build-up is designed so that most of the insulation sits above the deck. We decide this case by case once we can see inside the roof. If the covering is still sound and you are only patching it, the upgrade isn't usually required, and our repair or replace guide explains how to decide between the two.
What's included?
- Upstands, trims and kerbs reset to the new roof level
- Building control or building standards handled where needed
- Rigid insulation boards sized to the U-value target
- Survey of the deck, joists and existing insulation
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?
- Tyldesley · 2 mi
- Golborne · 3 mi
- Westhoughton · 4 mi
- Hindley · 4 mi
- Newton-le-Willows · 5 mi
- Walkden · 5 mi
Warm roof insulation upgrades in Leigh: questions
Do you cover Leigh?
Yes. Leigh is part of our Greater Manchester coverage, including postcode districts WN7. 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 Leigh?
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 warm roof upgrade cost in Leigh?
£2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, at North West guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
How thick does flat roof insulation need to be?
It depends on the insulation product and the U-value target. With common PIR boards, meeting a renovation target usually means well over 100 mm. Thinner, higher-performance boards are available where height is tight.
Can you insulate a flat roof from inside instead?
It is possible, but insulating between or under the joists creates a cold roof, which needs ventilation and carries a higher condensation risk. When the roof is being re-covered anyway, a warm roof from above is usually the better option.