How to Price a Full Roof Replacement: Strip, Felt, Batten and Tile Costs

Quick Answer: A full pitched roof replacement on a typical UK 3-bed semi-detached in 2026 costs £8,500–£18,000 for concrete tile, £14,000–£28,000 for clay tile, and £18,000–£42,000 for slate. The unit rate per m² of roof area is £100–£140 for concrete tile, £150–£220 for clay, and £200–£340 for slate, including strip, scaffold, batten and counter-batten, breather membrane, fixings, ridge, hip and verge details. Most full roof replacements span 8–14 working days on site, with scaffold up for 2–4 weeks. Single-storey extensions or bay windows typically add £80–£180 per m² over standard pitched roof rates due to detailing and small areas.

Summary

A full re-roof is priced from the area of roof slope (not floor plan), the tile or slate type, the existing structural condition, and the scaffold envelope. The single biggest variable that surprises homeowners is scaffold — typically £1,800–£4,500 for a 3-bed semi for the duration, accounting for 12–18% of total project cost. The second is whether the original timber substrate (rafters, ridge board, eaves) is sound or needs partial replacement.

The trigger for re-roofing rather than spot-repair is usually one of three conditions: nail-sickness across the roof (galvanised or steel nails corroded across the whole slope, leading to progressive slipping), tile or slate deterioration (concrete tile spalling, slate delamination, clay tile crazing), or felt failure (1950s–1980s bitumen sarking torn or perished, water ingress to battens). Once any of these reaches "more than 20% of roof area affected", spot repairs cost more over five years than a full strip.

UK Building Regulations (Approved Document L1B) treat re-roofing as a notifiable structural change and require thermal upgrade where over 25% of the roof envelope is renewed. This means insulation upgrade is almost always required as part of a full re-roof — £25–£60 per m² added to the package, but unlocking the homeowner's best opportunity to insulate the loft properly while access is open.

Key Facts

Quick Reference Table

Spending too long on quotes? squote turns a 2-minute voice recording into a professional quote.

Try squote free →
Roof type and finish 3-bed semi (2026) 4-bed detached (2026) Programme
Concrete tile (Marley Modern type) £8,500–£14,500 £12,500–£21,000 8–10 days
Clay tile (Sandtoft, Russell or similar) £14,000–£21,000 £19,000–£30,000 9–12 days
Welsh slate (Penrhyn / Ffestiniog) £24,000–£38,000 £35,000–£55,000 12–18 days
Spanish slate (Cupa, Burlington) £18,000–£28,000 £26,000–£42,000 12–16 days
Reclaimed slate £18,000–£26,000 £24,000–£38,000 14–20 days
Reclaimed clay tile £18,000–£28,000 £26,000–£42,000 14–18 days
Synthetic slate (Marley Eternit Cembrit) £10,000–£16,000 £14,500–£23,000 8–12 days

Detailed Guidance

How to Measure for a Re-Roof Quote

Roof area is calculated from slope area, not plan area. Each elevation:

  1. Measure plan length × plan breadth at eaves
  2. Multiply by slope factor: 30° pitch = 1.155, 35° = 1.221, 40° = 1.305, 45° = 1.414
  3. Add 5% for verge and detail allowances

Example: 6.5 m × 4.0 m semi, 35° pitch, two elevations:

For a hipped roof, deduct 5–10% from rectangular calc and add hip area separately. For a complex roof (dormers, gables, valleys), measure each section.

Strip and Dispose

The first three days of a typical re-roof are strip and dispose. A 3-bed semi roof typically yields:

Disposal cost varies by material:

Total disposal cost £400–£900 typical for 3-bed semi. Add to quote as line item.

Substrate Inspection — The Hidden Variable

Once the existing tile and felt are off, the rafters and structural timber are exposed. Common findings:

Quote should always include a "subject to substrate inspection" clause with a unit rate for any rafter splicing or substrate replacement. £1,000–£3,000 contingency is standard for substrate repair on roofs over 50 years old.

The Insulation Question

Approved Document L1B applies to renovation work where more than 25% of the roof envelope is being renewed. Compliance routes:

Cold roof (insulation at ceiling level) — fibreglass or mineral wool batts laid between and over ceiling joists. 270–400 mm total thickness for U-value 0.16 W/m²K. £25–£40 per m² supplied and installed. Cheapest, most common.

Warm roof (insulation between/over rafters) — used where loft is converted to habitable space, or where ventilation can't be achieved cold. PIR boards (Celotex, Kingspan) 100–150 mm typical. £80–£140 per m² supplied and installed. Requires breathable membrane and ventilation strategy.

Hybrid (rafter + ceiling) — used in part-conversions; £60–£100 per m².

The L1B requirement is mandatory; pricing without it leads to Building Control refusing completion certification. Where the homeowner declines insulation upgrade, the work cannot lawfully proceed under Building Regulations.

Mechanical Fixing Compliance

BS 5534:2014+A2:2018 requires every tile and slate to be mechanically fixed in current installation. Pre-2014 roofs had perimeter-fixed-only patterns; current practice requires every tile clipped or nailed. This drove the move from cement-mortar bedding (which counted as fixing in older standards) to dry-fix systems for ridges, hips and verges.

For pricing:

Cement-bedded ridge/hip on new work is no longer standards-compliant — using it is a guarantee of insurance complications later.

Breather Membrane and Ventilation

The breather membrane (sarking felt) sits over the rafters and under the battens. Modern breather membranes (BS 5534 Class 1) allow water vapour to escape from the loft while preventing rainwater ingress. £4–£9 per m² supplied.

Eaves ventilation under BS 5250 must achieve a continuous 10 mm gap, total 25,000 mm² per metre run for vented eaves. Achieved via:

Where insulation reaches the eaves (warm roof), counter-batten + breather + ridge vent is the standard solution. £8–£18 per m² added for ventilation strategy.

Scaffold — Honest Pricing

A 3-bed semi scaffold typically:

Typical 2026 scaffold rates:

Towers are not adequate for full re-roof — only for spot repairs. Half-elevation scaffolds (rear only) are sometimes sufficient for re-roofing one slope; £900–£2,200 for the duration.

Scaffolding companies typically invoice the scaffolder; the roofing contractor passes through with 0–10% margin. An honest quote shows scaffold as a separate line.

Frequently Asked Questions

How long does a full re-roof take?

Site time: 8–14 working days for typical 3-bed semi; 12–18 days for 4-bed detached; 16–24 days for complex roof with multiple gables and dormers. Add 1–2 days for scaffold erect and 1 day for dismantle. Weather-dependent: rain stops work; expect 25–40% weather contingency on programme in winter months.

Can I re-roof in stages — one elevation at a time?

Yes, but it costs more per m² because of duplicated scaffold and mobilisation. A staged re-roof typically costs 18–30% more than the same area done in one phase. Sometimes justified where the homeowner cannot fund or vacate for the full job; rarely the right technical answer.

Do I need planning permission to re-roof?

Not normally — like-for-like re-roofing is permitted development. Material change (concrete to slate, or vice versa) on a property in a Conservation Area or where Article 4 directions apply may require planning. Listed buildings always require Listed Building Consent for roof material change.

How much does it cost to insulate the loft as part of the re-roof?

Cold roof (270 mm mineral wool at ceiling): £1,800–£3,200 for a 3-bed semi loft. Warm roof (PIR between rafters + over): £8,000–£14,000 for a 3-bed semi loft converted to insulated. The cold roof is the much more common and cost-effective option for an unconverted loft.

Is reclaimed slate or tile worth using?

Yes, where matching is the priority. For Conservation Area or Listed Building work, reclaimed material may be the only acceptable option. Reclaimed slate is 30–50% cheaper than new Welsh slate but requires careful sorting for size matching (Welsh slate sizes vary by quarry). Reclaimed clay tile is essential for matching pre-1960 housing where moulds are no longer in production. Premium for sorting and matching: £20–£40 per m² over new material cost.

Regulations & Standards