Llanelli at a glance
- Postcode districts
- SA15
- Population
- about 49,591 (GeoNames)
- Council area
- Carmarthenshire County Council
- Building approval
- Carmarthenshire County Council building control, or a registered building control approver
- Nearest main town
- Swansea, about 10 miles
- Guide price region
- Wales (−8% on West Midlands rates)
Why choose a green roof in Llanelli?
In a place like Llanelli, 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 Llanelli, flat roofs are typically found on lock-up garage blocks on estates, and on shops with flat-roofed rear stores below flats. Wales averages roughly 1,460 mm of rain a year, among the wettest in Britain, so we design for steady run-off: proper falls, clear outlets and upstands well above the finished roof.
How much does a green roof cost in Llanelli?
For Llanelli we use Wales rates: £4,050–£7,450 is the guide for a 20 m² insulated extension roof finished as a sedum green roof, VAT included. 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 | £4,050–£7,450 |
| Extension (20 m²), EPDM, new deck + insulation | £2,600–£4,500 |
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
- Gravel strips kept clear around edges and outlets
- Root-resistant membrane or separate root barrier
- Structural check of joists, deck and supports
Building regulations in Wales
The Welsh Approved Document L applies. Renovating more than half of a roof over a heated room means upgrading it to around 0.16 W/m²K where feasible, and new extension roofs are built to 0.13 W/m²K. Welsh Government guidance is that most re-roofing needs building control approval, so check whenever more than a quarter of a roof is replaced or repaired. We deal with the application as part of the job. More on the rules.
Which nearby areas do we also cover?
Green and sedum roofs in Llanelli: questions
Do you cover Llanelli?
Yes. Llanelli is part of our Carmarthenshire coverage, including postcode districts SA15. 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 Llanelli?
Where the work needs approval it goes to Carmarthenshire County 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 Llanelli?
£4,050–£7,450 for a 20 m² insulated extension roof finished as a sedum green roof, at Wales 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.
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.