The roof covering is a building’s first line of defence against the weather. Scottish slate is a long-lasting roofing material, and although slate roofs have a finite life, a lifespan of up to – or beyond – 100 years is quite common.
It’s wise to inspect slate roofs regularly to spot potential problems as soon as they appear. Regular maintenance and repairs will ensure that your slate roof remains watertight and continues to perform well.
Look out for:
- broken, cracked or missing slates on the roof or ground, especially after bad weather
- dislodged slates at roof edges – slates here are particularly vulnerable
A single missing slate will let in only a limited amount of water. But if not put back in place, the sarking (wooden boards) beneath will decay. This will then lead to further loss of slates. Poor repairs will only make the situation worse.
‘Nail sickness’ – one of the most common causes of problems with slate roofs – occurs when the iron nails used to secure slates to the sarking rust through. Individual slipped slates can be secured again, but there may come a point where the number of slates affected means this is no longer cost effective. Instead it may be better to strip back and reslate the entire roof.
Slate hasn’t been quarried in Scotland since the 1950s and supplies for replacement purposes are very limited. So it’s best to reuse slates for maintenance and repairs wherever possible.