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)
What makes a good extension roof in Llanelli?
Ponding against the house wall is a common reason for replacing an extension roof in Llanelli. When the deck dips near the wall or the fall runs the wrong way, water sits against the abutment and eventually gets in. A new roof with corrected falls moves the water to the gutter.
Around Llanelli, flat roofs are common on low-rise post-war blocks of flats and on newer estates where the first extension roofs are now being replaced. 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 new extension roof cost in Llanelli?
Guide price in Llanelli: £2,600–£4,500 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at Wales rates. 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 | £2,600–£4,500 |
| Extension (20 m²), GRP, new deck + insulation | £2,750–£4,950 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £2,750–£4,800 |
| Single garage (18 m²), EPDM rubber | £1,450–£2,600 |
Which flat roof system suits a kitchen extension?
On a plain rectangular extension, EPDM rubber is a strong, quiet choice that can often be laid in one sheet. It handles the slight movement between an extension and the house well.
Where the roof has a lantern, several rooflights or an internal corner, GRP fibreglass forms neat, rigid details around each one. Torch-on felt is a proven layered system and keeps costs down, though near timber cladding or at fragile junctions we may prefer a cold-applied method. If the extension is overlooked from upstairs windows, a sedum green roof is worth considering, provided the structure can take the extra load.
Whatever the membrane, the insulation sits above the deck as a warm roof. Our warm vs cold roof guide explains why.
What's included?
- Free survey of the roof, abutment and room below
- Building control handled where needed, and a written workmanship guarantee
- Staged strip-out so the room stays weathertight
- New abutment upstand and flashing, plus rebuilt rooflight kerbs
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?
Extension and kitchen 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 new extension roof cost in Llanelli?
£2,600–£4,500 for a 20 m² extension roof in EPDM with a new deck and insulation, at Wales guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Why does my extension ceiling get damp in winter if the roof isn't leaking?
That is often condensation in a cold roof, where warm, moist air reaches the cold underside of the deck. A warm-roof replacement with a vapour control layer usually solves it.
How do I know my extension roof needs replacing rather than repairing?
Repeated leaks, a soft deck, wet insulation or widespread cracking point to replacement. A single defect on a dry, sound roof can usually be repaired.