Can you replace a single roof slate?

Slates are hung in overlapping rows that roofers call courses. Every slate is nailed near its head to the battens, the horizontal timber strips the slates hang on, and the course above covers those nails. That overlap keeps the rain out. It is also why nobody can simply unscrew a cracked slate and drop a fresh one into the gap.

What does the roofer actually do?

First the broken pieces come out. A slate ripper is a flat metal blade with a hook at its tip. It slides up under the course above, snags the old nails and cuts or pulls them out. With the gap open, the roofer looks at the underlay, the sheet membrane lying under the battens, for tears or sagging, and checks that the batten behind is sound and dry.

The replacement slides up into the gap until its head lines up with its neighbours. It cannot be nailed at the head, because the slates above are in the way, so it is held at the bottom edge instead. On a roof in good order that is the whole job: one slate, the rest of the slope left alone, and a roof that looks as it did before the gale.

There are two usual ways to hold a replacement slate at its tail, and the choice depends on the roof in front of us.

What exactly is a tingle?

The strip, in lead or copper, goes by that name. The roofer nails it to the batten through the joint between the two slates below, slides the new slate up over it, then folds the free end of the strip up and over the bottom edge of the slate. It is simple and suits almost any slate roof. The folded tab stays visible, though, and on a slope carrying several repairs a scatter of small metal tabs can be seen from the street.

When is a slate hook used instead?

A hook is a metal fixing that catches the tail of the slate, and it looks neater from below. Slate maker Cupa says hook fixings are not suited to any pitch under 25º, and BS 5534 puts the lowest pitch for natural slate at 20 degrees. So the steepness of your roof helps decide the fixing. On a shallow slope a tingle is the safer choice, and we measure the pitch before choosing.

A new slate has to be the same length and width as the ones beside it, or it will not lap properly and water can track past it. Thickness matters too. A slate that is much thicker or thinner than its neighbours sits proud or hollow, and wind gets underneath it.

Can a new slate match an old roof?

Colour is the harder part. Slate from different quarries varies in shade, and an older roof's slates have weathered for years. A fresh slate can stand out badly on the front slope of a terrace. Where that matters, a reclaimed slate of the right size and tone is often the better match. On a listed home, keeping the roof looking the same is a matter of care, and any change of material is a question for Somerset Council's planning team before work starts.

Sometimes the best source is your own roof: a sound slate lifted from a hidden rear slope or a porch goes on the front, and the new one is fitted where nobody looks. Tiles raise the same questions about profile and shade, covered in our answer on matching old roof tiles.

One slate on the lawn after a windy night is usually just that: one slate, one repair. A second and a third from the same slope within a few months tell a different story.

Why do several slates slip at once?

The nails holding a slate roof can corrode over time, and once they give way slates slide out of their courses one after another. Roofers call this nail sickness. Every slate on that slope hangs on nails of the same age, so replacing them one by one turns into a running cost, and re-slating can be the better buy. Rotten battens do the same, and our guide on whether roof battens need replacing explains the signs.

Can you just replace a few broken tiles?

Yes, a handful of tiles can be swapped in much the same way. MyJobQuote gives £150 to £200 for five tiles as a typical UK range (Oct 2026). For the causes, see why roof tiles slip, or our pitched roofing page. Send us a photo of the gap from the ground; we survey the slope, show you pictures of it, and give one written price.