Cracked or missing ridge mortar
Ridge and hip tiles on older roofs are bedded on sand-and-cement mortar. Mortar is rigid, the roof moves and the weather freezes and thaws — so over 15 to 25 years the bedding cracks, crumbles and eventually lets ridge tiles go.
What it looks like from above
- Hairline or open cracks running along the mortar joint between ridge tiles
- Missing sections of mortar leaving a visible void under the ridge tile
- Ridge tiles sitting slightly proud, twisted or out of line with the run
- Loose mortar debris in the valleys or gutters below the ridge
What happens if it's left
- Water tracks in behind the ridge tile and soaks the roof timbers at the apex
- A gale can lift a poorly bedded ridge tile clean off — a genuine safety risk below
- Once one tile goes, the run either side loses its restraint
How it's normally fixed
Re-bedding the affected run, or re-ridging the whole roof with a dry ridge system that uses mechanical fixings instead of mortar. Dry ridge costs more up front and does not need re-doing every couple of decades.
Common questions
How long does ridge mortar last?
Typically 15 to 25 years in Scotland's climate, less on exposed and coastal properties where freeze-thaw and wind loading are harsher.
Is cracked ridge mortar an insurance matter?
Gradual deterioration is normally treated as maintenance rather than an insured event. Storm damage where a ridge tile is dislodged is a different case, and that is where dated photographic evidence helps.
Think you've got this on your roof?
We photograph every elevation, circle each defect and grade it by severity — £99 residential, £149 commercial, report within 24 hours.