Roofers in London: Roof Replacement, Repair and What It Costs

The standard roof type in London Victorian and Edwardian terraced housing is a dual-pitched plain tile or natural slate roof, typically at a pitch of 40-45 degrees (steep enough for traditional materials, and the standard in most conservation areas). Materials used: Natural Welsh slate: the highest quality and most durable slate used in London Victorian housing, quarried from Wales. A well-laid Welsh slate roof can last 100+ years. Many London Victorian terraces still have their original Welsh slate. Where repairs are being carried out, using matching Welsh slate is required in most conservation areas. Imported slate (Spanish, Chinese): lower cost than Welsh slate, available at £20-£40/m2 supply versus £60-£120/m2 for Welsh. Lifespan 30-50 years for good quality Spanish slate. Often acceptable in conservation areas if the colour and texture match. Chinese slate is lower cost but quality is variable. Clay plain tiles: the traditional alternative to slate in London, with a warm reddish-brown appearance. Handmade clay tiles are the standard in conservation areas; machine-made clay tiles are the cost-effective alternative. Concrete roof tiles: not appropriate for most conservation areas but common in 1930s-1980s London suburban housing. Available as flat, plain, or interlocking profiles. Modern interlocking tiles (Marley, Redland) are durable and low-cost. Flat roofs (asphalt, felt, GRP, EPDM): on rear additions, extensions, and bay window roofs. See the flat roof extension guide for more detail.

Most London roof problems are presented to homeowners as a choice between repair and full re-roofing. The correct choice depends on: The age and overall condition of the existing covering: a Victorian slate roof that is 60-70 years post any previous re-lay, with widespread slipped and missing slates, failed lead valleys, and deteriorated battens and underlay — this is a re-roofing job. Patches will work short-term but the entire covering is at end of life and will require progressive patchwork at increasing cost. A Victorian slate roof that is in generally good condition with a small number of individual slipped or cracked slates and a failed section of leadwork in one valley — this is a repair job, and the repair will provide another 20-30 years of service if the rest of the roof is genuinely sound. The honesty problem: some London roofing contractors find it financially advantageous to recommend re-roofing when repairs would suffice. The recommendations differ by thousands to tens of thousands of pounds. The safeguard is: get at least two roofing reports from different contractors; ask specifically what the condition of the battens and underlay is under the good areas of slate (this requires a closer inspection); and consider paying an independent roofing surveyor (£300-£600) to give you an unbiased assessment before committing to a full re-roof.

Re-roofing costs in London (full strip and re-cover, including scaffold, new breathable underlay, new treated timber battens, tile/slate supply and lay, new lead valleys and flashings, making good to verges and ridge): Standard pitched roof, natural Welsh slate, Victorian terrace (50-70m2 roof area): £8,000-£15,000. Standard pitched roof, imported Spanish slate, Victorian terrace: £6,000-£11,000. Standard pitched roof, concrete interlocking tiles, 1930s semi or terrace: £4,500-£8,000. Standard pitched roof, clay plain tiles: £7,000-£14,000. These are for the roof covering only on a standard house in London — they include scaffold, materials, and labour. They may not include: chimney work (repointing, rebuilding chimney stack, DPC to chimney base); fascias, soffits, and gutters (add £1,500-£4,000 for replacement fascias, soffits, and guttering); party wall works on shared chimney stacks; or rot repairs to the timber structure if found during strip-out. Ridge tiles, hip tiles, and valley flashings are typically included in re-roofing quotes — always confirm this when comparing quotes.

Slipped slates or tiles: in a natural slate roof, slates are held by two nails through the slate into the batten. As the nails corrode over decades, the nails fail and the slates slip downward. In a clay or concrete tile roof, tiles may be nailed or may be held only by their nib (a projection that hooks over the batten) — an un-nailed tile slips in high wind. Individual slipped or cracked slates can be re-fixed with a 'tingles' (a metal clip) or replaced. If most nails are corroded, full re-slating is required. Failed lead valleys: the lead flashing in the valley between two roof slopes (or between the main roof and a rear addition) degrades over time through UV exposure, thermal cycling, and crystallisation. Signs: brown water staining in the top-floor rooms, water following the valley rafter into the house. Failed lead valleys in an otherwise sound roof can be replaced without full re-roofing. Blocked gutters causing damp: blocked gutters overflow, saturating the soffit boards, fascias, and top of the external walls, leading to damp penetration at ceiling level. A simple gutter clean (£100-£250 for a Victorian terrace) prevents this. Failed chimney flashings: the lead or mortar flashings at the junction between the chimney stack and the roof slope are a common failure point. Water enters behind the flashing and runs down the chimney inside the house. Chimney flashing repair: £400-£1,500 depending on whether lead or mortar flashings are used.

Roofing is one of the trades where quality varies enormously and where unreliable contractors are unfortunately common — partly because roofing is out of sight and problems may not manifest for months or years after poor work is done. How to find a good London roofer: National Federation of Roofing Contractors (NFRC) members: the professional body for the roofing industry, with member vetting and insurance requirements. The NFRC website allows homeowner searches for vetted members. Recommendations from neighbours, architects, or local tradespeople who know the contractor's work. Checkatrade or Trustpilot-verified reviews of contractors who have completed roofing works in London. Get at minimum three written quotations — significant differences in price should be questioned and the scope confirmed to be equivalent. Confirm the contractor is VAT-registered (if the quote is over approximately £85,000 VAT registration is mandatory, but many smaller roofing contractors are VAT-registered below this threshold) — unregistered contractors working above the threshold is a red flag. Confirm the contractor carries public liability insurance and that the quote is in writing with a defined scope, specification, and programme. Do not pay the full amount in advance — a reasonable deposit (10-25%) followed by stage payments, with a retention held until the end of the defects period (typically 12 months), is the appropriate commercial structure.