Pricing and quoting, 29 October 2026
How to price a roofing job: pitched, flat and the extras
Price a roofing job in three parts: the main covering per square metre (your gang day rate divided by the area you cover in a day, plus materials with waste), the fixed extras such as scaffold, skips, leadwork and ridge, and any building regulations upgrade the work triggers. Then add your margin. The area and the extras matter more than the tile price.
How do you measure a roof for pricing?
Measure each slope's true area. Plan area (the footprint seen from above) understates a pitched roof. Multiply the plan area by the pitch factor, or measure rafter length × slope width from the scaffold or drawings.
| Pitch | Multiply plan area by |
|---|---|
| 22.5° | 1.08 |
| 30° | 1.15 |
| 35° | 1.22 |
| 40° | 1.31 |
| 45° | 1.41 |
The factor is 1 ÷ cos(pitch), rounded to two decimal places. Measure ridges, hips, valleys and verges in linear metres separately, because they're priced per metre.
If you're working from drawings, our guide to measuring PDF drawings covers scaling and area. One young roofer we spoke to said plainly, "I don't know how to read drawings", and learning to take quantities off a plan changed how quickly he could price.
How do you work out a price per square metre?
Divide your gang's day rate by what they cover in a day, add materials with waste, then your margin. Our guide to converting a day rate to a price per m² goes through the method; the calculator below does the sum.
Your numbers, not a promise. Change any figure to match your firm.
Output is the number that decides your price, and it's the one to be honest about. Use what your gang achieves on an average roof, after loading out, cutting in and weather stops, not what they did on their best day.
A worked example: pitched re-roof
Re-roof a semi-detached house in concrete interlocking tiles
Strip and re-cover a gable-ended semi: 48 m² on plan at 35°, so 48 × 1.22 = 58.6 m², call it 59 m². Three-person gang at £260 each per day (labour, overheads and margin) = £780 a day. They strip, felt, batten and tile about 15 m² a day on this roof. Materials marked up 15%. Prices are illustrative; use your merchant's.
| Labour on the main slopes59 m² ÷ 15 m² a day = 4 days × £780 | £3,120 |
| Tiles, battens, membrane, fixings59 m² × £24 with waste, at cost + 15% | £1,628.40 |
| Dry ridge system, 8.5 m£310 at cost + 15% | £356.50 |
| Verges, dry verge system both gables£240 at cost + 15% | £276 |
| Scaffold, erect and strike, 3 weeksscaffolder's quote £1,450 + 15% | £1,667.50 |
| Skips, two 8-yard£560 + 15% | £644 |
| Price before VAT | £7,692.40 |
| VAT at 20%£7,692.40 × 20% | £1,538.48 |
| Price to the client | £9,230.88 |
Overruns hurt most on short jobs: on a small job, one extra day can take all the profit. Pricing the other way hurts too. For example, a firm pricing commercial work at about £60 per m² where the market is nearer £36.50 won't win much of it. Working from your own day rate and output shows which jobs you can win at a profit and which you can't. Our guide to overheads per man-day shows how to build that rate.
How do you price a flat roof?
The same way, with different outputs and materials. Price the deck, the insulation if it's being upgraded, the membrane system and the edge details.
Replace a garage flat roof with a warm deck and single-ply
Strip a 3 × 6 m (18 m²) garage roof, new 18 mm OSB deck, vapour control layer, 120 mm PIR insulation, single-ply membrane, new trims. Two-person crew at £520 a day, 2 days. Materials marked up 15%. Illustrative prices.
| Labour: strip, deck, insulate, membrane, trims2 days × £520 | £1,040 |
| Deck, VCL, insulation, membrane, adhesive, trims£1,050 at cost + 15% | £1,207.50 |
| Skip£280 + 15% | £322 |
| Price before VAT | £2,569.50 |
| VAT at 20%£2,569.50 × 20% | £513.90 |
| Price to the client | £3,083.40 |
Check coverage figures against the manufacturer's data. One roofing and cladding firm we spoke to in Ireland had his board coverage on a job down as 0.75 m² per board when the correct figure for that board was 1.44 m²; an error like that nearly doubles the material line. The same check flagged an adhesive that wasn't compatible with XPS board.
Does a re-roof need building regulations approval?
In most cases, yes. Planning Portal guidance says re-roofing will in most situations need building regulations approval, to check structure, fire safety and energy efficiency. Councils commonly set the trigger at re-covering more than 50% of the roof area, or more than 25% of the whole building envelope. Because a roof is a thermal element, renovating it can require the insulation to be upgraded.
If you're registered with a competent person scheme for roofing, you can self-certify. If not, the client or you must apply to building control, and the fee should be on the quote or listed as an exclusion. Changing from slate to concrete tiles, or the reverse, can change the load on the roof and may need a structural check. Building regulations differ in Scotland, Wales and Northern Ireland.
What extras do roofers forget to price?
HSE says almost one in five deaths in construction involve roof work, and that all roofs should be treated as fragile until a competent person confirms otherwise. Safe access is part of the price, never an optional line. Your RAMS should match what you've priced.
Where Nexley fits
Nexley is the AI back office for UK trade firms: five AI assistants run your tenders, quotes, buying, scheduling and invoicing. It connects to the tools you already work in, you run it all from WhatsApp, and you approve everything. £799 a month.
For roofing, you send Nexley a voice note and photos from the survey ("semi, 48 on plan, 35 degree, concrete interlocking, three-week scaffold"). Nexley works out the slope area, prices it from your gang rate, outputs and merchant prices, adds your standard extras and exclusions, and drafts the quote on WhatsApp for you to check and approve.
Common questions
What's a fair price per m² for roofing?
It depends on the roof type, pitch, access and your gang's output, which is why published rates vary so much. Work it out from your own day rate and output, then compare with the market as a check.
Should scaffold go in the price per m²?
No. Price it as its own line. Scaffold depends on the height, access and length of hire, not the roof area, and showing it separately helps the client compare quotes fairly.
How much waste should I allow on tiles?
Allow for cuts at hips, valleys and verges, plus breakages. Simple gable roofs need less than roofs with several hips and valleys. Use the manufacturer's coverage data and adjust for the roof's shape.
Do I charge VAT on a re-roof?
If you're VAT-registered, re-roofing an existing house is normally standard-rated at 20%. Work on a new dwelling or some conversions can be different, so check with your accountant.
Sources
- Planning Portal: Building regulations, re-roofing
- Horsham District Council: Guidance for re-roofing projects
- East Suffolk Council: Replacing your roof covering and roof repairs (PDF)
- GOV.UK: Approved Document L, Volume 1: Dwellings
- HSE: Roof work
- GOV.UK: Buildings and construction (VAT Notice 708)
Every rule, rate and date above was checked against these sources on the date shown at the top.
Topic: Pricing and quoting
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