Green and sedum roofs in Hirwaun

Why choose a green roof in Hirwaun?

In a place like Hirwaun, 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.

Hirwaun's flat roofs are mostly on lock-up garage blocks on estates, with plenty on 1930s semis with flat-roofed garages and kitchen extensions too. 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 Hirwaun?

At Wales guide rates, a 20 m² insulated extension roof finished as a sedum green roof comes to £4,050–£7,450 including VAT. The fixed price comes after a free survey for new and replacement roofs.

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?

• Gravel strips kept clear around edges and outlets
• Warm or inverted build-up to suit the roof
• Root-resistant membrane or separate root barrier
• Drainage layer, filter and lightweight growing medium

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?

• Aberdare · 3 mi
• Treorchy · 6 mi
• Merthyr Tydfil · 6 mi
• Rhondda · 6 mi
• Mountain Ash · 7 mi
• Tonypandy · 8 mi

Other flat roof work in Hirwaun

• Flat roof replacement
• Single-ply membrane roofing
• GRP fibreglass roofing
• Warm roof insulation upgrades
• EPDM rubber roofing
• Flats, HMOs and block roofs
• All services in Hirwaun