When a slate roof comes off, the slates stack up on the scaffold and then in a skip, and it is easy to treat the whole heap as rubbish. It is not. Natural slate is a hard, dense stone that is cleft into thin plates, and a slate that has done its job for a lifetime on a Taunton terrace is often still sound. CORC publishes that well-kept slate can last 100+ years. The stone usually outlives its fixings, which is why the nails fail long before the slate does.
That gap is where the choices sit. A sound slate can be re-laid on a repair, kept back to match a roof that is only part done, sold on to a reclaim buyer or crushed and recycled once it has finished its working life. This post goes through each route in turn, from sorting the heap on the day to the slates you should never put back. It also covers the awkward case of fibre-cement slates that are not stone at all, because those need different care. If you are weighing a bigger job, our slate roofing page sets out the whole service.
Sorting sound slates from tired ones
Sorting starts as the slates come off, because a slate is easiest to judge in the hand, with a bucket of nails and a pencil close by for marking the doubtful ones. A good slate rings when you tap it, and a dull flat sound often means a hidden crack. We lay slates out by size on the day and check each one for the faults that decide where it can go next.
What are we looking for in each slate?
First, the edges and the nail hole. A slate that has slipped is often cracked through its fixing hole, and one with a big or torn hole is not worth re-laying. Second, the face. Slates that flake or split into layers have gone soft and will not shed water for long. Third, the size. A heap that is all one size is far more useful than a mixed one, since a buyer or a repair needs a run of matching slates.
Everything passes into one of three piles: sound slates for reuse or sale, slates with minor faults that suit garden uses, and broken slates that go for recycling. Be strict with the first pile. A cracked slate put back is a leak waiting to happen, and lifting it again later costs more than the slate was ever worth.
Can you do the sorting yourself?
Once the slates are on the ground, yes. The roof itself needs access set up properly. Slate is slippery when wet and brittle underfoot, so stay off the slope and leave the lifting to the people with the scaffold.
Reusing sound slates on repairs
The most useful second life for a good slate is another stretch of the same roof. When a roof needs a patch repair, a stock of slates from the same building will fit the gauge and the colour better than anything bought new. A slate that came off your own roof has already weathered to the shade of its neighbours, which is the hard part to copy.
Why do old slates slip in the first place?
Usually the stone is fine and the fixing has failed. Iron nails rust through where they pass through the slate, and the slate slides down. That is nail sickness, and it can strip a slope slowly over the years. A re-laid slate goes back with a fresh fixing, so it can last on a roof where the original nail could not.
On a repair we keep the sound slates that come off, clean the nail holes, refix them with the right nails or clips and bed them back in the right course. Slate is laid in overlapping courses, and the headlap is the overlap of one course over the slate two courses below it. A re-laid slate has to keep that overlap, or water will find it. Our slate roof repair page shows what a repair visit covers.
Is a repair ever the better buy than new slates?
When the fault is local. A few slipped slates, a split on one course or a slope that is sound apart from the ridge is a repair. If the fixings have gone across a whole slope, more patches simply push the fault to the next slate, and a re-slate using the sound slates salvaged from that slope may suit better. The survey and the photos of your own roof show which it is.
Matching slates on a part-finished roof
Matching is where old slates earn their keep. Taunton has Victorian and Edwardian terraces in slate, and a replacement set in a different colour or thickness shows from the road. Keeping the sound slates from the stripped slope gives a repair that blends in with its neighbours, and a roofer who holds a small stock back can often finish a job with no new purchases.
Which slates should you keep back?
Set aside the best ones, whole and even in colour, in the sizes your roof uses. Slates from a back slope that is out of sight can be swapped for weathered ones on the front, so the street side keeps its look. Our page on how to match replacement slates goes through colour, size and thickness. A thin slate beside a thick one rocks and lets water in, so thickness matters as much as the face.
Does a conservation area change what you can do?
It can. In a conservation area the covering is part of the character of the street, and the planning team at Somerset Council is the place to check what applies to your address. Class C permitted development normally covers swapping the covering on a house, while a listed house needs listed building consent too if the job reaches its character. A conservation area does not make the slates themselves any harder to reuse, but it does make a close match more important.
Taunton's conservation areas include Castle Green and Bath Place, and Park Street and Wellington Road. Check with Somerset Council before changing a covering on streets like these.
Selling old slates to reclaim buyers
Slate that is sound, in a good run of one size, has resale value. Architectural reclaim yards and private buyers who are matching an old roof will take it, and some roofers buy slates as part of a job. There is no fixed price. What a lot is worth depends on the size, the colour, the quantity and the condition, so ask a reclaim buyer to look at the pile before you agree anything.
What makes a lot worth buying?
Quantity and uniformity. A buyer needs enough slates in one size to cover a job, so three hundred matching slates are easier to sell than ten sizes from ten roofs. Stack them on edge, off the ground and out of the rain, since a wet pile on soft ground picks up grit and moss. Count them, note the size, and take photos of the face and the holes before you list them.
How does selling help the cost of a re-slate?
It offsets part of the bill, though never all of it. MyJobQuote gives an average of around £7,800 for a new slate roof (Oct 2026), a typical UK range that moves with the size of the roof, the slate and the access. Salvaged slate sold well takes a little off, but it does not change what decides the price: the area, the pitch, the covering and the scaffold.
Agree before the work starts who owns the slates. A contractor who strips the roof will usually clear the skip, so say if you want them kept. We note this at the survey so it is written down, and the quote stays one total.
Recycling slates that cannot go back
Slates with cracks, torn holes or soft, flaking faces are finished as a roof covering, but they are not waste yet. Stone is inert, and there are sensible uses for the broken pieces.
What can you use broken slates for?
Garden jobs take them well. Whole slates make stepping stones, bed edging, a path border or a plant label, and a slate set on edge is a neat barrier against grass creeping into a border. Cut with care: slate splits along its layers and the edges are sharp, so wear gloves and eye protection. Smaller pieces and shards can go into a drive or a hardcore base, where the hard stone packs down well. A builders' merchant or a skip company may take a clean, sorted load, and a reclaim yard may take broken lots for the same reason.
What about slate that cannot be reused or recycled?
Bag or stack it so it is easy to move, and keep it apart from timber, felt and rubble. Mixed waste is harder to recycle because every material needs separating again at the other end, so a skip with clean, sorted slate stands a better chance of being reused. Rules at recycling sites change, so check with Somerset Council before you load the car. A roofer who clears a job away must carry the waste off with the right documents, so ask who is doing it.
It is worth a moment of thought before anything is thrown out. Salvaged stone is free garden material, and good stone sent to landfill wastes the quarrying and the transport that went into making it.
Slates you should not reuse
Not every slate-looking covering is slate, and the difference matters more than anything else in this post. Some roofs were laid in fibre-cement slates, a manufactured sheet made to look like stone, and some older products contained asbestos. HSE's advice treats any building constructed or refurbished before 2000 as likely to contain asbestos. That is a reason to stop and ask before you handle, break or sell an old grey slate of unknown origin. Our page on natural and fibre-cement slate explains how they differ.
How can you tell natural slate from fibre-cement?
You usually cannot be sure by eye. Natural slate has a split, slightly uneven face and edge and rings when tapped, while a manufactured sheet looks regular and flat. A survey can tell you which you have, and if there is any doubt about asbestos, a sample goes for testing before anything is lifted. HSE counts careful removal of weathered asbestos cement, where the sheets stay whole, as non-licensed work; once they are broken up in quantity, the job becomes notifiable. Never sell, give away or crush a slate you suspect is asbestos cement. It travels on a consignment note, never in an ordinary skip.
Which natural slates stay on the scrap pile?
Slates that flake, delaminate or crumble, slates with torn nail holes and slates broken across the middle. A slate with a hairline crack may hold in a garden path, but it does not belong on a roof. Pitch matters too: BS 5534 indicates a minimum of 20 degrees for natural slate, so a reused slate is no help on a roof that is too shallow.
Slate sorting, selling and recycling
Is it worth keeping old slates from a roof I am replacing?
If the slates are sound and in a usable size, yes. They can match a later repair, go to a reclaim buyer or be kept for garden use. If the roof is being stripped anyway, say before the work starts that you want them set aside, so they are not lost in the skip.
Can reclaimed slates go straight back onto my roof?
Only after sorting. Each slate needs checking for cracks, flaking and torn holes, then refixing with sound nails or clips at the right headlap. A roofer can sort them on the day and re-lay the good ones, and the survey photos show which slopes suit salvaged slate.
How do I get rid of broken slate in Somerset?
Keep it clean and separate from timber and felt. Garden and hardcore uses suit small pieces, and a builders' merchant or skip company may take sorted loads. Check Somerset Council's rules for recycling sites before you load up, and ask your roofer to clear anything they strip.
More on this subject: Slate roofing in Taunton
