Slate is priced by the square metre, but a slate roof is never only slate. Underneath every course sit nails, battens, underlay and lead, and on an older house in or around Bath those hidden parts often decide the bill more than the slate itself does. A quote that looks high may include new battens, a breathable underlay and fresh lead in the valleys. One that looks low may be relaying old slate on timber that should have been renewed. This guide sets out the typical UK ranges published by third-party cost guides, explains what sits behind each figure, and shows where the money goes on a repair, a part re-slate and a full re-roof. The ranges are national, so treat them as a way to read a quote, not as a quote. Your own figure comes once a roofer has stood on your slopes and photographed what is there.
What natural slate costs per square metre
The figure most people search for is the installed rate per square metre, and it varies mainly with where the slate was quarried. The figures in this table come from MyBuilder's slate roof cost guide (2026), last updated in August 2026, and are typical across the UK.
| Item | Typical UK range |
|---|---|
| Natural slate, installed | £100 to £180 per m² |
| Welsh slate, installed | £140 to £180 per m² |
| Spanish slate, installed | £100 to £130 per m² |
| Semi-detached house, Spanish slate | £7,000 to £10,000 |
| Slater's day rate | £200 to £300 |
Your fixed quote follows the survey. This table is a guide to what a fair price looks like, and the range within each row is wide for good reasons.
Read the table as a starting point for questions, not an answer. The installed rate covers the slate, the fixings and the labour to lay it. It does not usually cover scaffolding, stripping the old covering, skips, new lead, or repairs to the timber underneath, and those can add a great deal on a period house. When two quotes differ by thousands, the difference is rarely the slate. It is usually what each roofer has decided to renew below it.
Roof area is the other driver. A simple gable roof on a semi has two plain slopes. A Victorian villa may have hips, valleys, dormers and a turret, each of which means cutting slate to shape and dressing lead around it. Cut slate is slower to lay and wastes more material, so the same number of square metres can cost noticeably more on a complicated roof. The slater's day rate tells you why: the more time the details take, the more days the job runs.
Re-slating a whole roof: where the total comes from
A full re-slate strips the roof back to the rafters and builds it up again. On a typical job that means removing the old slate and sorting what can be saved, taking off the battens and any old felt, checking the rafters, laying a new underlay (the waterproof layer on the rafters, below the battens, that turns back wind-blown water), fixing new battens (the timber strips the slates hang from), and then slating with new nails or hooks. The ridge, hips and verges are rebuilt, and the lead at the stack and valleys is usually renewed while the roof is open.
Several costs sit outside the slate rate. MyBuilder's new roof cost guide (2026) puts scaffolding at about £1,125 and waste disposal at £100 to £1,000 as typical UK figures. Scaffold on a three-storey Bath terrace, or one that has to bridge a basement area, can be more involved than on a suburban semi, which is why we price it from the survey rather than a rate. The figure you sign up to is the one we put in writing after that visit.
The size of the job also brings Building Regulations into play. Re-covering does not normally need approval when the work affects less than 25 per cent of the building envelope and less than 50 per cent of the roof. Re-slating the whole roof goes past those limits, so it needs building control approval and the roof may need its thermal performance brought up to standard. If a new covering material would make the roof covering 15 per cent or more heavier, approval is needed for that reason too, with a check on the structure. The Planning Portal guidance on re-roofing sets out those rules, and we handle the notification side where it applies.
Insulation is the cost that most often surprises people. If the roof needs a thermal upgrade, the work and materials sit on top of the slating price, and they should be named on the quote rather than discovered later.
Welsh, Spanish and man-made slate compared on price
On the published figures, Welsh slate costs £140 to £180 per square metre installed, against £100 to £130 for Spanish, as typical UK ranges from MyBuilder's slate roof cost guide (2026). On a whole roof that gap adds up, and it is the single biggest choice that changes the total. We confirm the slate and its price in the written quote that follows our survey.
The difference is not only the name. Welsh slate is the material many older Bath houses were first roofed with; a Bath Preservation Trust casework note on one Grade I house describes its roofs as predominantly Welsh natural slate. Spanish slate comes from many quarries, and its quality varies between them and between grades. A good Spanish slate from a reliable source can be a sound roof. A poor one can carry iron inclusions that rust and stain, or split along its layers in time. We go through those differences on our page comparing Welsh and Spanish slate.
Man-made slate, made from fibre cement or resin, is lighter, more uniform and usually cheaper to buy. The cost guides we rely on do not give a separate installed figure for it, so we will not invent one; it is priced on survey like the rest. Two points matter more than its price. First, its life is generally shorter than good natural slate: MyBuilder's 2026 guide gives fibre-cement and synthetic slate a typical 30 to 50 years, against 75 to 100 years for Spanish slate and over a century for good Welsh slate, so the cost per year can be closer than the purchase price suggests. Those are typical figures, and exposure and workmanship move them. Second, on a listed building or a prominent roof in a conservation area, swapping natural slate for a man-made one is a change in appearance that may need consent, and the Trust has supported replacing artificial slate with natural Welsh slate on at least one Bath terrace.
Reclaimed slate sits between the two. It can match a weathered roof better than anything new, but supply, sorting and breakage vary from batch to batch, so it is quoted on the day rather than from a table.
Repairs: slipped slates, tingles and small leaks
A slate roof usually needs repair long before it needs replacing, and repair is where we start if the roof can take it. Typical UK figures from MyBuilder's roof repair cost guide (2026) put a minor repair, such as a small leak or a few slates, at £100 to £300. A moderate repair runs £500 to £1,000, and major repair work starts at about £2,500. Storm damage fixes are typically £500 to £1,500. Your fixed price follows once we have seen the roof.
The usual small job is a slipped or cracked slate. Because each slate is nailed under the course above, you cannot simply nail a replacement back in. The new slate is slid into place and held with a tingle, a narrow strip of copper or lead nailed to the batten in the gap and folded up over the slate's tail. Done neatly, a tingle is hard to spot from the ground. On a roof dotted with them from years of earlier visits, it is a sign the nails are failing everywhere, not just in one spot.
Access is the cost driver most people underestimate. A slate low on a single-storey back roof can be reached from a ladder and roof ladder. The same slate near the ridge of a three-storey house needs scaffold or a tower, and that alone can outweigh the labour. Matching the slate is the other. A modern grey slate pushed into a weathered Welsh roof will show, so we keep salvaged and reclaimed slate for repairs where the colour matters.
The hard question is when patching stops making sense. If slates are slipping on every slope and the underlay has perished, the money spent on repeated visits would be better put towards the roof. We set out that decision on our page about whether to repair or re-slate, and we will tell you which side of the line your roof sits on.
Lead, ridges and the details that move the price
Slate keeps water off the open slope. Everywhere the slope stops, at a chimney, a wall, a valley or a ridge, the roof relies on other materials, and they account for a good share of the risk and the cost on an older house.
Lead at the chimney and abutments
A flashing is the lead dressed over a joint to stop water getting in, such as where the slope meets a chimney or a side wall. Under it, soakers (small pieces of lead tucked under each course of slate) carry water back onto the roof. Typical UK figures from MyJobQuote's chimney leadwork guide (September 2026) put a patch repair at £150 to £250 and a full replacement at about £570 on average, less without scaffold and more with it. Your fixed quote follows the survey.
Valleys and parapet gutters
A valley is the internal angle where two slopes meet, usually lined with lead so the water from both runs down it. A parapet gutter is the lead-lined channel behind a stone parapet wall, a common detail on Bath terraces. Both are hidden from the street, both take a heavy load of water, and both fail at splits, laps and drips. Relining them is skilled work, and the lead is specified by its code, the industry grading of sheet thickness, to suit the job. Royston Lead's brochure lists codes 5 to 8 for parapet and box gutters, and Leadworx gives code 5 as 2.24 mm thick and code 8 as 3.55 mm.
Ridge and verge
On some slate roofs the ridge is finished with clay, stone or slate ridge pieces. The British Standard for slating, BS 5534:2014, means mortar alone is no longer relied on to hold them, so they need a mechanical fixing. MyBuilder's dry ridge guide (2026) gives a typical UK range of £40 to £60 per linear metre for a dry ridge system, which uses clips and seals instead of mortar. Your own ridge is priced once we have measured it.
Bath roofs, consent and what a survey settles
Bath adds a layer that a national cost guide cannot price. The whole city is a World Heritage Site, the city-wide conservation area spans roughly half of Bath, and the Bath Record Office counts around 5,000 listed buildings. On a listed house, changing the covering, rebuilding a chimney or altering a dormer requires listed building consent; in Bath the council, B&NES, grants it. Unauthorised work is a criminal offence. On an unlisted house in the conservation area, re-slating like for like is unlikely to raise questions, but a change of material or appearance is worth raising with B&NES planning first.
Heritage detailing costs more because it takes longer. Diminishing courses, swept valleys, lead rolls and lime-pointed stacks are slower to build than a modern roof. A slate of the right size and colour may have to be sourced, or sorted from reclaimed stock. None of that shows in a per square metre rate, and all of it shows on a well-built Bath roof.
A survey is how those unknowns become a price. We go up, lift slates where we need to see the nails and battens, check the lead, and take photographs, so the evidence is in your hands as well as ours. The fixed price then comes to you in writing, with the scope set out item by item: what is being renewed, what is being kept, the slate specified, the scaffold, and who deals with building control. Where a repair is enough, we recommend and price the repair instead. The workmanship is covered by our written 10-year guarantee.
Price is also tied to how long the roof will last. A cheaper slate on new fixings may outlive a better slate laid back on tired battens, so the specification matters as much as the headline. Our answer on how long a slate roof lasts goes through that, and our slate roofing service covers the work itself.