The short answer
A slate tingle is a thin strip of metal, ideally copper or stainless steel, bent over the tail of a replacement slate to hold it where the original nail has failed. It is a standard repair, and a few on a roof are normal. Tingles in many places show nails failing across the slope, which points towards a re-slate rather than more patching.
What a tingle is and how it works
A nail through a hole near the top edge fixes each slate to a batten. Battens are the timber laths that cross the rafters. The courses overlap, so every nail is hidden beneath the slate above it. That is a tidy system until a nail rusts through, because the slate it held slides down and cannot be re-nailed without lifting the slates around it.
A tingle solves that problem. It is a narrow metal strip, nailed to the batten below the gap, which is then folded up and over the lower edge of the replacement to grip it. The slate is slid into its course, the strap is turned forward, and the repair is done without disturbing the neighbours. From the ground you can sometimes see the result: a small tab showing at the bottom edge of one slate.
Roofers also use slate hooks and clips for similar jobs. The idea is the same: a metal part that grips the slate where a nail can no longer do it. Hooks have their own page: slate hooks.
Why a few tingles are fine
Tingles are a normal and accepted way to repair a slate roof. Even a sound roof will lose the odd slate for ordinary reasons. A branch lands on the slope, a slate is cracked by a ladder or a foot, or a single nail was poorly driven when the roof was laid. A tingle is the quickest way to put that slate back without a large job.
The material matters, so ask whoever repaired the roof what the straps are made of, because a good roofer will know. Copper and stainless steel do not rust, so a good tingle will outlast the nails around it. A strap that has bent, snapped or corroded is a repair that needs repeating, and a thin or mixed-metal strap is a poor choice on a roof that is meant to last.
Taken singly, a tingle is no cause for alarm. It records that one fault was dealt with without disturbing the slates around it. That is worth knowing when you come to buy or sell, because it shows the roof has had some attention.
When too many point to a problem
The pattern matters more than the count. A handful of tingles scattered over a roof that has stood for generations is unremarkable. A band of them across one slope, or tingles on every slope, is different.
That pattern shows nails failing one after another. Each tingle marks a place where a nail went. If the nails that remain are the same iron nails from the original build, they will go too, and the roof will keep producing new slips one at a time. Our slipped slates page covers why slates slide, and the cumulative effect is called nail sickness.
A useful test from the street is to look for density. If you cannot find a clear stretch of slope with no tabs on it, the fixings are probably tired. If the tabs sit low on the slope, near the gutter, check that damp has not also reached the eaves timbers.
The limits of the repair
A tingle holds a slate by its tail, which is a different grip from a nail through the head. In ordinary weather it does the job. It suits the occasional slate, though, and makes a poor basis for a whole roof. The more the covering depends on straps, the further it drifts from its original form.
There is also the batten to think about. The strap is nailed into the same timber that may already be soft. If the batten under a tingle is damp or crumbling, the strap will not hold and the slate will come away again. This is why we check battens from the loft before agreeing that a patch will last.
Tingles also add up visually. On a street where the roofs are on show, a patchwork of straps looks untidy and suggests the roof has been left to deteriorate. That matters if you are selling, or if the house sits in a conservation area where roofs are part of the view.
What we do about it
Ask for any repair to be recorded, with the slope and the number of straps, so the next survey has something to compare against.
When we survey a roof with tingles, we note which slopes they sit on and lift a few neighbouring slates to see the nails. If the nails hold well and the battens are firm, the tingles stay, and any further slips are repaired the same way.
If the nails are rusting and the pattern is wide, we tell you clearly and set out the choice. We weigh that choice in full on the repair or re-slate page. A re-slate replaces iron nails with copper or stainless ones, so straps are no longer needed to hold the roof together.
Stone tiles behave differently from slate. They are heavier and are normally pegged or nailed in a different way, which our page on stone roof tiles explains.
After the survey you get the photographs and a written fixed price, so the tingles and the nails are there for you to see. For the bigger picture, see our slate roofing service.
