Flat RoofingContractors

Upgrades

Green and sedum roofs in Heswall

Can your flat roof in Heswall carry a green roof? It depends on the joists, the spans and the deck. We check the structure first, tell you if strengthening or an engineer's input is needed, and only then quote for the waterproofing and sedum build-up.

Sedum green roof with a gravel border and inspection chamber on a single-storey extensionComputer-generated example image

Heswall at a glance

Postcode districts
CH60, CH61
Population
about 29,075 (GeoNames)
Council area
Wirral Council
Building approval
Wirral Council building control, or a registered building control approver
Nearest main town
Birkenhead, about 6 miles
Guide price region
North West (−5% on West Midlands rates)

Why choose a green roof in Heswall?

Garden rooms and outbuildings in Heswall, as elsewhere, often have small flat roofs that are seen from the house and garden. A sedum finish helps them blend in, provided the structure is strong enough and the roof underneath is built properly.

In a town like Heswall, flat roofs are commonly found on 1960s and 1970s link-detached houses with flat-roofed garages and porches or bungalows with flat-roofed side extensions and dormers. 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 Heswall?

Guide price in Heswall: £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.

JobGuide 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?

  • Drainage layer, filter and lightweight growing medium
  • Gravel strips kept clear around edges and outlets
  • 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?

Green and sedum roofs in Heswall: questions

Do you cover Heswall?

Yes. Heswall is part of our Merseyside coverage, including postcode districts CH60, CH61. 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 Heswall?

Where the work needs approval it goes to Wirral 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 Heswall?

£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.

Can a green roof have a rooflight in it?

Yes. The rooflight sits on a raised upstand with a gravel strip around it, so the planting stays clear of the glazing and the upstand stays visible and dry.

Do I need to water a sedum roof?

Usually only in the first season, during long dry spells, while the blankets establish. After that, sedum copes with dry weather well.

Other flat roof work in Heswall

Green and sedum roofs in Heswall: get a fixed price

Free survey and a written fixed quote for replacement and new roofs. No obligation.

Call usGet a guide price