Thurso at a glance
- Postcode districts
- KW14
- Population
- about 7,390 (GeoNames)
- Council area
- The Highland Council
- Building approval
- The Highland Council building standards
- Guide price region
- Scotland (−5% on West Midlands rates)
What makes a good extension roof in Thurso?
Ponding against the house wall is a common reason for replacing an extension roof in Thurso. 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.
Thurso's flat roofs are mostly on 1960s and 1970s link-detached houses with flat-roofed garages and porches, with plenty on lock-up garage blocks on estates too. Scotland averages roughly 1,570 mm of rain a year, with the west far wetter than the east, so drainage, falls and wind uplift are part of every specification we write.
How much does a new extension roof cost in Thurso?
Guide price in Thurso: £2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, including VAT at Scotland 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 | £2,650–£4,650 |
| Extension (20 m²), GRP, new deck + insulation | £2,850–£5,100 |
| Extension (20 m²), EPDM, insulation + 1 rooflight upstand | £2,850–£4,950 |
| Single garage (18 m²), EPDM rubber | £1,500–£2,650 |
Why does water pond or leak where the extension meets the house?
Usually because the fall runs the wrong way, the abutment detail has failed, or the roof has sagged close to the wall. The junction with the house is the most common leak point on an extension roof.
If the roof falls towards the house, or the deck dips near the wall, water sits against the upstand and finds any weakness in the flashing above. Older roofs often have the felt simply turned up the brickwork with no cover flashing, or a flashing that has pulled out of its joint. A patch will not change a fall. We re-firr or use tapered insulation so water runs away from the wall, then form a new upstand, usually 150 mm above the finished roof, with a flashing chased into the mortar joint.
Rooflights and lanterns are the other weak point. A lantern needs a properly built kerb with the membrane dressed up and under its frame. We rebuild rooflight upstands within the roof job; we do not supply the lantern itself. Our guide to ponding water explains the causes in more depth.
What's included?
- New abutment upstand and flashing, plus rebuilt rooflight kerbs
- Staged strip-out so the room stays weathertight
- Building standards handled where needed, and a written workmanship guarantee
- Free survey of the roof, abutment and room below
Building standards in Scotland
In Scotland the building standards technical handbooks (Section 6 for energy) apply, and the council's building standards service decides whether a building warrant is needed. Like-for-like repairs to a roof covering can be exempt; alterations, structural work and new roofs usually need a warrant before work starts. The domestic roof benchmark is 0.12 W/m²K, applied as far as reasonably practicable on an existing roof. More on the rules.
Which nearby areas do we also cover?
Extension and kitchen roofs in Thurso: questions
Do you cover Thurso?
Yes. Thurso is part of our Highland coverage, including postcode districts KW14. Surveys and roofs are carried out by vetted roofing teams working under S&K Property Investments and Improvement Ltd.
Who checks building standards for a flat roof in Thurso?
Where the work needs approval it goes to The Highland Council building standards. 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 Thurso?
£2,650–£4,650 for a 20 m² extension roof in EPDM with a new deck and insulation, at Scotland guide rates including VAT. The fixed price comes after a free survey for new and replacement roofs.
Is EPDM or GRP better for a kitchen extension?
Neither is better in every case. EPDM suits simple rectangular roofs with few details, while GRP is often chosen where there are rooflights, corners or occasional foot traffic.
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.