Does one slipped slate mean my roof will leak?
Not necessarily, and not always immediately. A well built slate roof has more than one layer of defence against water, so a single displaced slate does not automatically mean water is getting into the building. But a slipped slate is a sign that the roof’s outer defence has been breached, and it should not be left, because the layers underneath were never meant to be a roof’s only protection.
Slate roofs work by overlapping courses of slate shedding water down and off the roof, course by course, well before it can reach the timber structure underneath. Underneath the slates themselves there is usually a layer of timber boarding (sarking) and, on many roofs, a secondary waterproof or breathable membrane. That second layer is a backup, not a permanent substitute for a complete slate covering. Our guide to sarking and ventilation explains what sits underneath the slates in more detail.
Signs a slipped slate is already letting water in
- A damp patch, discolouration, or staining on a ceiling or in the corner of a room below the affected slope, particularly one that appears or grows after rain.
- Daylight visible through the roof from inside a loft or attic space.
- A musty smell in a loft space that was not there before.
- Slipped or missing slates visible from ground level or from a neighbouring window.
If you are a tenant or landlord dealing with a ceiling that is already showing wet patches, our damp advice guide covers what to do next.
Why a quick repair matters even if it looks minor
The longer a gap in the slate covering is left, the more chance wind driven rain has of finding its way past the secondary layers underneath, and the more likely the surrounding timber and any underlay is to be affected. A repair that would have been straightforward when the slate first slipped can become more involved once water has reached the timber underneath, which is one of the reasons small, prompt repairs are worth doing rather than leaving.
Email us photos of the roof and what floor it’s on, or how many levels up it is, and we’ll tell you what we need to give you a price.
Worried about a slipped slate?
Email us photos of the roof and what floor it’s on, or how many levels up it is, and we’ll tell you what we need to give you a price.
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