Nail fatigue and slipped slates
Natural slate can last a very long time, but the nails holding it corrode. Slipped slates are a common early sign that a roof is approaching the end of its covering life.
Chimneys and flashings
Tall stacks weather, lean and lose mortar. Lead or cement flashings around them can crack, letting water track into the roof space and down chimney breasts.
Valleys and parapet gutters
Terraced houses often have hidden valleys and parapet gutters that collect debris and are hard to see from the street. Blockages can cause persistent damp inside.
Alterations and extensions
Loft conversions, dormers and rear extensions change how a roof is loaded and drained. Flat roofs on extensions tend to have shorter lifespans than the main roof.
- Removed or cut timbers in the roof space
- Heavier replacement coverings on original timbers
- Ageing felt flat roofs
What to do next
If the roof is a concern, a RICS Level 3 Building Survey or a dedicated roof survey will give you a clearer picture. A drone survey can add close views of areas hidden from the ground.