Scotland Regional Winner, Heating Installer Awards 2026Highly Commended, Scottish Energy Efficiency Awards 2025
🎉 Scotland Regional Winner at the Heating Installer Awards 2026
Scotland Regional Winner, Heating Installer Awards 2026Highly Commended, Scottish Energy Efficiency Awards 2025
🎉 Scotland Regional Winner at the Heating Installer Awards 2026
Home / Blog / Solar panels on a slate roof in Scotland
You can put solar panels on a slate roof in Scotland, and the job differs from a tiled roof in three places. The fixings have to pass between the slates to the rafters without resting on any slate, every slate that cracks needs a matching replacement, and the array has to hold against the wind loads an exposed Scottish roof takes in winter.
Sean Hogan · Heat Geek engineer · Updated October 2026 · 15 min read
Slate brings practical problems a concrete tile never does. A broken Scots slate cannot be swapped for a new one from a builders’ merchant, a single-nailed Scots slate comes off in a different way from a double-nailed Welsh one, and a four-storey tenement needs scaffolding a bungalow can do without. Each of those affects the price, the time on site and the questions worth asking an installer.
Yes. Natural Scottish slate, Welsh and Spanish slate and fibre-cement slate all carry solar panels, and the MCS installation standard for solar PV deals with slate roofs by name. The deciding questions sit elsewhere: the direction and shading of the slope, whether the timbers can take the extra load, and how many years the slates have left. Direction and shade have their own guide, on which way a roof should face for solar in Scotland.
Condition comes first on an old slate roof. The panels stay up for decades, and the slates underneath have to last as long, because reaching them later means taking the array off and putting scaffolding back up. From the ground, look for slipped slates, gaps in the courses and pieces of slate in the gutter after a storm. From the loft, look for damp marks or rot on the sarking boards, the timber boards Scottish slates are nailed to.
The usual cause of slipped slates in Scotland is nail sickness, where the iron nails holding each slate rust through. The Scottish Lime Centre Trust, in a roofscape survey of Mauchline written for East Ayrshire Council, puts the tipping point at about 20% of the roof area: beyond that, stripping and reslating the whole roof makes more sense than chasing individual slates. If your roof sits near that line, reslate first and fit the panels to the new roof.
A new roof brings one more check. MIS 3002 tells the installer to contact the warranty provider of a roof covering still under warranty, and to get your written agreement before going ahead if the solar installation could void it.
Scottish slate came from a handful of places: Ballachulish in Lochaber, Easdale and the other slate islands in the Firth of Lorn, and quarries along the Highland Boundary Fault such as Aberfoyle and Dunkeld. Historic Environment Scotland’s Engine Shed describes Ballachulish slate as the strongest of them, thanks to its quartz content, and Easdale slate by the ripples across its face. The last Scottish quarry closed around 1955, and none operates today.
Scots slate looks and behaves unlike the imported kind. The slates are thick, irregular in size and fixed with a single nail at the head onto sarking boards, and roofers laid them in diminishing courses, with the largest slates at the eaves and the smallest near the ridge. Welsh and Spanish slates come in regular sizes with two nail holes and run thinner than Scots slate.
The Mauchline survey gives a sense of the mix on one Ayrshire town’s roofs: 61% Scottish slate in diminishing courses, 36% Welsh or Spanish slate, 3% concrete tile.
Newer homes and some re-roofs use fibre-cement slates, which are thinner again, uniform and lighter.
Each type changes the job on the roof:
roofers trimmed the shoulders of single-nailed Scots slates so that neighbouring slates could be moved aside to reach a broken one, as Historic Scotland’s Moses Jenkins describes in the Building Conservation Directory, and an installer uses the same access at each fixing point. A spare has to match the course it goes into, because the sizes shrink toward the ridge.
regular sizes make spares easier to match, but two nails per slate mean freeing each one with a slate ripper before it lifts.
light and uniform, which makes spares easy to size, though the thin sheets crack under a knee or a boot.
Ask the installer to name your slate type on the survey. The hook, the flashing and the spares all follow from it.
“Very pleased with fitting service and the performance of the solar panels and batteries. A good neat job completed with everything clearly explained.”
Stephen Sydenham, ★★★★★ Google Review
Panels on a pitched roof clamp to aluminium rails, and the rails clamp to brackets fixed into the roof structure. On a slate roof those brackets are slate hooks: stainless steel arms that screw through the sarking into a rafter, or into a timber fixed between rafters, then run up under the course above and out between two slates. With the slates laid back, only the arm shows above the surface, and the rail and panel cover it.
The rule that shapes every slate roof solar mounting comes from the IET Code of Practice for grid-connected solar PV, which MIS 3002 adopts: brackets on a slate or tiled roof must not put load on the slates. MIS 3002 Issue 6.0 (18 March 2026) allows one exception, for a bracket designed to spread its load evenly across the roof covering without damaging it, and only where MCS 012 testing proves it. In practice, the weight of the panels, and the wind pulling on them, travels through the hook into the timber.
Installers use two main approaches at each fixing point:
| Fixing method | What happens to the slate | How it stays watertight |
|---|---|---|
| Slate hook with flashing | The slate at the fixing point comes off, the hook goes onto the rafter, and the slate goes back with a notch or a flashing piece where the arm passes | A flashing plate under the course above, sealed around the hook arm. Where it suits: Regular Welsh, Spanish or fibre-cement slate, and Scots slate where spares match |
| Slate-replacement plate | The slate at the fixing point comes out and stays out | A purpose-made plate takes the slate’s place, with a raised, sealed collar the hook passes through. Where it suits: Roofs where cutting slates would break too many, or spares are scarce |
MIS 3002 adds a check on the finished roof: where the work would leave slates displaced with gaps bigger than the roof had before, the installer has to notch or flash those slates. Before you sign, ask which mounting kit the quote uses, whether it holds an MCS 012 certificate, and how many fixing points the design has.
A well-fitted array leaves a slate roof as watertight as it found it. The damage, when it happens, comes from the fitting: a knee on an unsupported slate, a hook arm bearing on a slate face, or a slate levered off when its nail should have been cut. On an old roof with rusting nails, expect a few slates to break anyway, and plan for them.
A good installer plans for breakage. Lifted slates go into a stack on the scaffold, kept in course order if the roof runs in diminishing sizes, and matching spares arrive before the work starts: reclaimed Scots slate of the right size for a Scottish roof, Welsh or Spanish slate of the same size and thickness for a regular one, and replacements from the same range for fibre-cement. Reclaimed Scottish slate takes the longest to find. The Mauchline survey notes that re-dressing second-hand Scottish slate wastes 30% to 40% of it, and the Engine Shed reports that good reclaimed stock is running down.
Many installers use lead-free flashing kits at each hook: purpose-made plates that slide under the course above and seal around the hook arm, with no lead to cut and dress on the roof. The cables that run into the loft go through their own cable flashing.
Ask for photographs of the fixings and flashings before the panels cover them. They cost the installer nothing and show you work you will never see again from the ground.
Our installations carry a 5-year workmanship guarantee.
Air moving over a pitched roof pulls upward on the panels, and that uplift is strongest at the edges, corners and ridge. Design wind speeds on the UK wind map rise toward the north and west, and a house on a hill or near the coast takes a further increase for altitude and exposure, so a cottage above Largs and a villa in a sheltered Glasgow suburb need different fixing layouts.
MCS 012 is the product standard for pitched roof installation kits. Manufacturers send their kits for testing against wind uplift and rain penetration, and the certificate states the kit’s maximum design wind uplift resistance. The fire test applies to in-roof kits and kits fixed to a combustible substrate, so an above-roof kit on slate falls outside it in the usual case. MIS 3002 requires solar PV mounted above a pitched roof to use MCS 012 certified kits. If no certified kit suits a roof, the installer has to hold evidence of a structural assessment and a wind loading calculation for that specific mounting system, and evidence of how the roof’s weathertightness was kept. The standard lists BRE Digest 489, on wind loads for roof-based PV, among its references.
Edges get their own rule. MIS 3002 keeps panels 400mm back from any edge of a domestic roof, unless the installer takes specific measures on five points:
Extra fixings to resist the stronger uplift in that zone (with extra timbers for them where needed)
A secure ridge
Rainwater running off as it did before
No risk from snow building up and sliding off
Less nuisance from wind noise
On slate, weatherproofing comes down to the laps. Each slate overlaps the two courses below it, and the rain stays out as long as those overlaps stay intact. A hook that lifts a slate, or a slate left sitting proud, opens a path for driving rain, which is why the flashing at each fixing point matters as much as the hook itself.
“Aventus Eco upgraded our battery storage quickly and really easily, and fixed problems our original installer had left. Nothing but praise for the company.”
Colin Moss, ★★★★★ Google Review
Slate cracks under a boot, so installers work from a scaffold at the eaves with edge protection, and they reach the upper courses on roof ladders or crawling boards hooked over the ridge, which spread a person’s weight across many slates instead of one. MIS 3002 asks for risk assessments before any work starts, and notes that a solar job combines a fall risk, awkward lifting at height and electric shock, hazards that roofers and electricians each know but seldom meet together.
Many older Scottish roofs pitch steeply, and the steeper the slope, the more of the job happens from roof ladders, which adds time to each fixing point.
A tenement adds height: scaffolding for a four-storey front elevation that stands on the pavement needs permission from the council as roads authority under section 58 of the Roads (Scotland) Act 1984, and the City of Edinburgh Council lists scaffolding among the activities that need a road occupation permit. A rear-elevation scaffold sits in the back court, which in a tenement means the neighbours’ shared drying green.
The order of the week, from the scaffold going up to the MCS certificate, follows the same sequence as any other roof, set out in our guide to the solar panel installation process in Scotland.
Tenements, from the sandstone streets of Hyndland in Glasgow to the Marchmont tenements in Edinburgh, put the ownership question first. Start with your title deeds. Tenement deeds usually make the roof the common property of all the owners, and some give it to one flat. If the deeds say nothing, the Tenements (Scotland) Act 2004 makes the top-floor flat extend to the roof over it. The Act’s Tenement Management Scheme covers the management and maintenance of shared parts and says nothing about who owns them. Solar panels count as an improvement, so on a commonly owned roof they need every co-owner’s consent unless the deeds say otherwise. Local Energy Scotland’s guidance for tenement owners, published on 28 April 2025 and written by Harper Macleod, sets out that position and how owners can agree installation and maintenance between them.
Villas bring a structural question instead. The large Victorian houses of Pollokshields or the Grange in Edinburgh tend to have hipped roofs, valleys, dormers and several chimneys, and every one of those features breaks up the slopes and adds edges. MIS 3002 sends any traditional cut roof with hips or valleys to a structural engineer, and counts dormers, valleys and parapets as features that raise the risk of snow building up. Many of these streets also sit in conservation areas, and the planning side of that is covered in our guide to the planning rules for period and listed homes.
If your villa or tenement is in or around the city, our page on solar panel installation in Glasgow shows how we design and fit systems for its housing.
“The team was well coordinated and communicated well during the process. They completed the work to a very high standard and minimised any disruption to our home.”
Ben, ★★★★★ Google Review
A concrete interlocking tile lifts out, takes a hook in its trough and drops back without a nail to cut. A slate roof takes longer at nearly every step, and the extra time lands in specific places:
a nailed slate has to come off without breaking, then go back notched or flashed, or make way for a replacement plate.
reclaimed Scots slate in the right course size takes time to find, and someone has to source it before the scaffold goes up.
steep pitches mean more work from roof ladders, and tall tenements mean bigger scaffolds and, on a pavement, a council permit.
hips and valleys bring in a structural engineer under MIS 3002, and exposed sites need more fixing points to meet the wind load.
Published estimates of the slate premium disagree with each other by several times, so treat any single figure with caution. A useful quote lists the fixing kit, the number of fixing points, the allowance for spare slates and the scaffold as separate lines, which lets you compare two installers on the same roof.
One part of the price stays the same whatever covers your roof. Solar panels installed in homes carry 0% VAT until 31 March 2027, and Home Energy Scotland offers no grant or loan for solar PV, so the saving comes from the zero VAT rate and export payments under the Smart Export Guarantee. Our 2026 guide to solar panel costs in Scotland breaks the rest of the bill down.
The fixing method, the spares and the scaffold for your house all follow from the slate on your roof and the state of the timbers under it. A good survey should name the slate and check the sarking and rafters from the loft before anyone designs the array. Our £0 survey ends in a design and a written quote for your roof.
Yes. Natural Scottish slate, Welsh and Spanish slate and fibre-cement slate all take solar panels, using slate hooks fixed to the rafters or slate-replacement plates. In Scotland the main check is the condition of the slates and sarking, since the roof has to outlast the panels.
No, when the installer works to the MCS standard. The hooks carry the load into the rafters without resting on the slates, and flashings keep each fixing point watertight. A few old slates may break during fitting, so a good installer in Scotland sources matching spares before the work starts.
Stainless steel slate hooks screwed through the sarking into the rafters, with aluminium rails across them and the panels clamped to the rails. Some Scottish installs use slate-replacement plates, which take the place of a slate and seal around the hook.
They take longer to fit, because each slate at a fixing point has to come off and go back without breaking, and matching spares cost time to source in Scotland. Ask for a quote that lists the fixing kit, fixing points, spare slates and scaffold separately. Solar panels installed in homes carry 0% VAT until 31 March 2027.
Only with your neighbours’ agreement in most cases. Scottish tenement deeds usually make the roof common property, and solar panels count as an improvement, so every co-owner has to consent unless the deeds say otherwise. If the deeds are silent, the Tenements (Scotland) Act 2004 makes the top-floor flat extend to the roof over it.
If the roof is near the end of its life, yes. In Scotland the common sign is nail sickness, and conservation guidance puts the point for full reslating at about 20% of the roof area affected. Reslating first saves taking the panels off and re-scaffolding later.
For an MCS-certified installation, yes. MIS 3002 requires pitched roof mounting kits certified to MCS 012, which tests them for wind uplift and rain penetration, and for fire where the kit is in-roof or fixed to a combustible substrate. If no certified kit suits a roof in Scotland, the installer must hold a wind loading calculation and weathertightness evidence instead.
Inside Scotland's Most Resilient Village Hall
What Solar Salesmen Don’t Tell You
Was My Own Heat Pump Install a DISASTER? The Results Are In...
Panasonic L Series Heat Pump Masterclass
Heat Pump vs My House: The Truth About New Build Installs | Part 1
This Is What Kills Heat Pumps Early (And How to Stop It)
From Council houses to £2,000,000 Mansions we do it all with Heat Pumps…
How to DESTROY a heat pump in 3 years....ECO4 install
