Why Roof Pricing Is So Variable
Ask five roofers for a quote and you'll get five different numbers. That's partly because roofing costs depend on multiple variables: roof size, pitch, access difficulty, material choice, insulation requirements, and the condition of the existing structure.
It's also because some roofers quote low to win the job and then add extras once they've started. At AC Roofing, every quote is fixed-price and itemised. The number we give you is the number you pay — no surprises, no hidden charges.
Flat Roof Costs
Flat roof replacement for a typical rear extension (15–25m²) in North London: EPDM rubber system: £2,000–£3,500. GRP fibreglass system: £2,500–£4,500. Three-layer felt system: £1,500–£2,500.
These prices include stripping the old covering, inspecting and replacing damaged decking where needed, installing the new membrane, and all trims and edge details. Insulation upgrades (now required by building regulations) add £500–£1,200 depending on the specification.
Pitched Roof Replacement Costs
Full strip-and-retile for a typical three-bed terraced house in North London: Concrete interlocking tiles: £5,000–£8,000. Plain clay tiles: £7,000–£12,000. Natural slate: £10,000–£18,000.
These prices cover stripping all existing tiles, replacing battens and felt with a breathable membrane, retiling, new ridge and hip tiles, and renewing all lead flashings. Scaffolding is typically £800–£1,500 depending on access and is included in our quotes.
Repair Costs
Not every roof needs replacing. Many issues can be resolved with targeted repairs at a fraction of the cost: Individual tile replacements: £150–£400. Ridge tile re-bedding (full ridge): £400–£800. Lead flashing renewal: £300–£600 per section. Valley gutter repair: £400–£900. Emergency tarping and temporary repair: £200–£500.
We always assess whether repair is viable before recommending replacement. If a repair will give you another 10+ years, that's what we'll recommend.
Factors That Increase Costs
Several factors can push costs above the typical ranges: Difficult access (terraced properties with no side access, conservation areas requiring specific scaffolding). Structural timber damage requiring replacement of rafters or joists. Asbestos in older roof coverings (requires specialist removal). Listed building requirements specifying heritage materials. Dormer windows, valleys, and complex roof geometries that increase labour time.
During our free inspection, we identify every factor that affects pricing — so your quote reflects the actual scope of work with no surprises once we start.
How to Get an Accurate Quote
The only way to get an accurate roofing quote is with an on-site inspection. Photos and satellite views can give a rough estimate, but they miss critical details like timber condition, insulation state, and access requirements.
We offer free, no-obligation inspections across North London. We'll measure the roof, assess its condition, discuss material options, and provide a written, fixed-price quote within 24 hours. Call 07415 302 589 or fill in our contact form to book.