Rawmarsh at a glance
- Postcode districts
- S62
- Population
- about 18,498 (GeoNames)
- Council area
- Rotherham Council
- Building approval
- Rotherham Council building control, or a registered building control approver
- Nearest main town
- Rotherham, about 2 miles
- Guide price region
- Yorkshire and the Humber (−5% on West Midlands rates)
Why choose a green roof in Rawmarsh?
Small commercial buildings and blocks in Rawmarsh with a flat roof sometimes add an extensive green roof as part of a refurbishment. The structural check and safe access for maintenance matter even more on these larger roofs, which may need edge protection or fall-arrest points for each visit.
Rawmarsh's flat roofs are mostly on 1960s and 1970s link-detached houses with flat-roofed garages and porches, with plenty on shops with flat-roofed rear stores below flats too. England averages roughly 870 mm of rain a year; the Pennine side of Yorkshire is wetter and windier than the east, so we specify for the site rather than the county.
How much does a green roof cost in Rawmarsh?
Guide price in Rawmarsh: £4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, including VAT at Yorkshire and the Humber 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 |
How is a green roof built on top of a flat roof?
From the bottom up, a green roof is a deck, a waterproofing system with root protection, then drainage, filter, growing medium and plants. The waterproofing does the job of keeping water out. The green layers sit above it.
- Warm roof build-up: vapour control layer, insulation and waterproof membrane on the deck, then the green layers on top. This is the usual choice on a home extension being re-roofed.
- Inverted build-up: waterproofing on the deck, then insulation boards designed to sit above it, then the green layers. This is common on terraces and some commercial roofs.
- Root barrier: roots will exploit any weakness, so the membrane needs to be root-resistant. Some membranes are tested as root-resistant; others need a separate root barrier laid on top.
- Drainage and edges: a drainage layer carries surplus water to outlets, and a gravel or pebble strip is usually left around edges, outlets, upstands and rooflights to keep them clear and accessible.
Upstands still need to rise around 150 mm above the finished surface, which on a green roof means above the top of the growing medium. We check that at the survey, alongside the external fire performance of the build-up where the roof is close to a boundary.
What's included?
- Pre-grown sedum blankets laid and watered in
- Structural check of joists, deck and supports
- Gravel strips kept clear around edges and outlets
- Drainage layer, filter and lightweight growing medium
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?
- Rotherham · 2 mi
- Wath upon Dearne · 3 mi
- Mexborough · 3 mi
- Wombwell · 5 mi
- Conisbrough · 5 mi
- Hoyland · 5 mi
Green and sedum roofs in Rawmarsh: questions
Do you cover Rawmarsh?
Yes. Rawmarsh is part of our South Yorkshire coverage, including postcode districts S62. 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 Rawmarsh?
Where the work needs approval it goes to Rotherham 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 Rawmarsh?
£4,200–£7,700 for a 20 m² insulated extension roof finished as a sedum green roof, at Yorkshire and the Humber guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Does a green roof leak more than a normal flat roof?
No, as long as it is built correctly. The waterproofing beneath is what keeps water out, and the green layers protect it from sun and weather. The main risk is building it on a weak or ageing membrane.
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.