Cracked mortar along the ridge is the most common roof defect in Medway. Why it happens, when it's urgent, and why cement isn't always the right answer.
The ridge is the very top of your roof, and the mortar holding those tiles in place takes more weather than anything else on the house. Look up at your ridge line — if you can see cracks, gaps or loose bits, you're looking at the most common roof repair in Medway.
Why It Fails
- Freeze-thaw — water gets into hairline cracks, freezes overnight, expands and widens them. This is what does the damage in Kent winters
- Solar movement — the ridge gets hottest and coldest and moves most
- Age — mortar simply doesn't last as long as the tiles it's holding
- Poor previous repairs — a fast job with the wrong mix fails quickly
What It Causes
Failed ridge mortar lets water in at the very top of the roof, where it can track down either side. It's a common cause of damp in upstairs rooms and a contributor to ceiling stains. Loose ridge sections are also a genuine hazard in high winds — they're heavy, and they land.
Is It Urgent?
Hairline cracking? Not urgent, but will get worse. Loose sections or open joints with visible gaps? Worth doing before the next storm season. It's not a job to leave through a winter once it's started.
The Modern Alternative
Traditional repointing is re-pointing the ridge with mortar. A dry-fix ridge system uses a mechanical fixing and a flexible foam gasket instead — no mortar to crack, and it holds indefinitely. It costs more up front but doesn't come back. On older homes, a traditional lime-based mortar may be the right choice to match what's there; cement mortar on an old soft-brick stack traps moisture and causes damage.
Ridge repointing is usually a day's work and priced per metre. Happy to have a look and tell you which of the two suits your roof.
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Costs and timings in this article are guides for Medway and Kent properties. Every roof is different — a survey is the only way to get an accurate figure.