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Roof Replacement Calculator

Plan a complete UK roof replacement in 2026: strip, dispose, batten, breather membrane, scaffold, and full installed cost — broken down line by line in £/m².

Roof Replacement Calculator

Plan the full replacement project: tear-off, disposal, decking allowance, code upgrades, crew duration, and total installed cost — all matched to your locale's currency and labour rates.

Estimated total replacement cost
£23,242
£126/m² · 22.3 squares · Concrete tile
Annualised over 50-year service life: £465/yr · Project duration: 1 day(s) on a 4-person crew
Material
£4,935
Labour
£9,676
Tear-off
£2,528
Disposal
£1,918
Underlay
£1,336
Deck repair
£740
Code upgrades
£1,432
Permit + misc
£677
Surface area
208 m²
slope factor 1.122
Crew time
3.3 man-days
1 day(s) wall-clock
Debris
9,124 kg
~24 cu yd skip

What this calculator does

This calculator estimates the full cost of a UK pitched roof replacement, itemised as your contractor’s quote should be:

  • Material — tiles or slates, ridge and hip tiles, dry verge and ridge systems, treated battens, breather membrane, fasteners
  • Labour — adjusted for pitch, complexity, and material handling difficulty
  • Strip-off — single or double layer to existing tile
  • Disposal — skip hire and tipping fees
  • Battens and underlay — BS 5534-compliant Grade A treated battens and BBA-certified breather (HR) membrane across the full deck
  • Sarking / decking repair — a percentage allowance for board replacement (mainly Scotland and the North)
  • Code upgrades — modern dry-fix systems, flue and verge upgrades

It also estimates crew duration and debris weight / skip size so you can plan scaffold hire, off-property days, and stress-test the contractor’s quote.

How to use it

  1. Roof footprint — enter the plan-view area in m². The calculator multiplies by the slope factor for actual roof surface.
  2. Pitch — UK roofs typically run 30–45°. Enter degrees or X/12.
  3. New material vs existing material — drives material cost and disposal weight.
  4. Region — London and South East run +25–35%; Scotland and Wales run –10–15%.
  5. Decking allowance — 8–15% on roofs over 40 years old or where sarking is in poor condition.
  6. Code upgrades — toggle on for dry-fix ridge / verge, modern membrane, ventilation upgrade.

Typical 2026 UK replacement costs

For a 110 m² semi-detached or terraced home (footprint), mid-cost region:

Material£/m² installedTotal costCrew time
Concrete interlocking tile£75–£120£8,500–£14,0005–7 days
Plain clay tile£110–£170£12,500–£19,0007–10 days
Reclaimed natural slate£150–£220£17,000–£25,0008–12 days
Welsh / Spanish natural slate£180–£300£20,000–£34,00010–14 days
Cedar shingle£140–£200£15,500–£23,0007–10 days
Single-ply membrane (flat sections)£85–£135£9,500–£16,0003–5 days

Sources: NFRC 2026 contractor benchmarks; Checkatrade 2026 cost guide; MyBuilder regional roofing data; BBA Agrément certified product price lists Q1 2026.

Regional variation in the UK

Labour rates drive most of the variance:

  • High cost (+25–35%): Greater London, Surrey, Hertfordshire, parts of Berkshire and Buckinghamshire
  • Above average (+10–20%): South East, Bristol, Bath, Cambridge, Oxford
  • National average: Most of the Midlands, Yorkshire, North West
  • Below average (–10–15%): North East, Wales, most of Scotland outside Edinburgh

Code-mandated items in BS 5534

The current BS 5534:2014+A2:2018 has tightened mortar bedding rules. Modern compliant re-roofs require:

  • Mechanically-fixed ridge and hip tiles — dry-fix systems compliant with BS 8612 (Klober Uni-Click, Manthorpe Easy-Fix, Marley Universal)
  • Mechanically-fixed verge — no mortar-only verges accepted
  • Treated Grade A battens — minimum 38×25 mm for tiles up to 5 kg, 50×25 mm above
  • BBA-certified HR breather membrane — Klober Permo Air, Tyvek Supro, or equivalent
  • Tile clipping and nailing pattern per BS 5534 Annex A — varies by exposure zone (England Zone 1 vs Highlands Zone 5)

Together these items add £600–£1,500 versus pre-2018 mortar-bedded construction.

Common UK gotchas

Sarking board replacement (Scotland and the North). 1×6 plank sarking that has woodworm or rot must be replaced — runs about £18 per m² of board. Budget £400–£900 on Scottish properties.

Dormer detailing. Each Velux installation runs £450–£850 to swap, plus flashing kit. Cheek tiles on dormer sides need bespoke cuts.

Lead flashings. Old lead at chimney, abutments, valleys must be replaced — Code 4 lead at £8–£14 per kg installed. Budget £200–£600 per chimney.

Asbestos cement underlay (pre-1985 properties). Requires licensed removal under CAR 2012 — adds £400–£1,200 plus laboratory analysis.

Repair vs replace decision

Repair if: under 50% of expected life, less than 5 broken slates / tiles, no widespread moss issue, ridge mortar still sound, no daylight visible from inside the loft.

Replace if: past 60% of expected life on slate (slate-nail sickness), past 70% on concrete tile, multiple slipped or cracked tiles in different planes, or you’re losing tiles in normal weather rather than just storms.

Sources: NFRC 2026 contractor pricing; BS 5534:2014+A2:2018; BS 8612:2018 (dry-fix ridge); Approved Document C of the Building Regulations (2026); BBA Agrément certified product database Q1 2026; Checkatrade and MyBuilder 2026 cost guides; Met Office HQ wind-event archive.

Frequently asked questions

How much does a full roof replacement cost in the UK in 2026?
A typical 110 m² semi-detached or terraced UK home re-roof in concrete tile costs £8,500 to £14,000 in 2026, including strip, scaffold, breather membrane, treated battens, ridge tiles, and waste removal. The same job in natural slate runs £18,000 to £32,000. Detached three-bedroom homes with hipped roofs typically run £12,000 to £22,000 in concrete tile. London and the South East run roughly 25–35% above the national average. Source: NFRC 2026 contractor pricing data, Checkatrade and MyBuilder cost guides.
How long does a UK roof replacement take?
A standard 110 m² concrete tile re-roof takes a four-person crew 5 to 7 working days from scaffold-up to clean-up. Natural slate takes 8 to 12 days because each slate is hand-cut and pre-drilled. Add 1 to 2 days for the scaffold to be erected before work starts and to be dismantled after. Weather is the biggest variable — UK rain delays push average projects 1 to 3 days beyond the quoted schedule.
Should I strip the roof or just overlay?
Always strip and replace. BS 5534 does not permit overlaying tile or slate on existing tile or slate, and most insurers void cover on overlaid roofs. Stripping reveals decking condition (sarking boards in Scotland and the North; rafters with no sarking in southern England), failed lath, and woodworm. Overlaying also adds 25–40 kg per m² of dead load — most older roofs cannot take it. The strip-and-replace approach gives you a fresh breather membrane, modern fasteners, and BBA-certified components.
What battens and underlay does the 2026 UK code require?
BS 5534 mandates Grade A graded and treated battens (38×25 mm minimum for tile, 50×25 mm for slate), and a BS 8747 / BBA-certified breather (HR) membrane like Klober Permo or Tyvek Supro. Flexible bedding mortar is now restricted — most ridge and hip details use mechanical clips and dry verge / ridge systems compliant with BS 8612. Always check the project against the latest NFRC Technical Bulletins.
What scaffolding will I need?
A semi-detached two-storey home typically needs a three-lift scaffold on the front and rear elevations: roughly 14–18 metres of frontage at £18–£28 per linear metre per week, hired for 2–3 weeks. Total scaffold cost runs £700–£1,800 on most domestic re-roofs. Tower scaffolds are not adequate for a full strip — only spot repairs. Edge protection is mandatory under the Work at Height Regulations 2005.
Will home insurance pay for replacement?
UK buildings insurance covers sudden insured-event damage — storm, lightning, fallen tree, fire — not gradual wear, moss damage, or age-related slate slip. Storm damage claims usually require winds of 55 mph or more recorded near the property; the Met Office archive is your evidence. After a storm, photograph damage immediately, file the claim before scheduling work, and get an NFRC-member contractor's written assessment for the loss adjuster.
How big a skip do I need?
A 110 m² concrete tile strip generates roughly 10–11 tonnes of waste — that's a single 12-yard skip plus a top-up, or a roll-on roll-off (RoRo) container at 20 yards. Slate is similar weight. Concrete tile waste is now mostly accepted as inert (non-hazardous) construction waste, but check with the skip supplier — old asbestos cement underlay (pre-1985) requires licensed asbestos removal.
How do I find a reliable roofer?
Use NFRC (National Federation of Roofing Contractors) — members are vetted annually, carry £2 million public liability minimum, and offer the NFRC-FairTrades complaints service. Cross-check on Checkatrade, MyBuilder, and TrustATrader. Get three written quotes itemising scaffold, strip, materials with brand and grade, ridge system, and waste disposal. Avoid quotes that are 25%+ below the others — they typically skip breather membrane upgrade or use ungraded battens.

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