Roof Valleys: The Leak Point On Older Medway Homes

A roof valley is where two slopes meet and channel the water from both. It handles more water than any other part of the roof — and on older homes in Medway, it's the most likely place to spring a leak.

The Two Types

Older roofs often use open valleys — bare lead or mortar between the tiles, visible from the ground. Newer roofs use closed valleys, where tiles are cut and laid over a hidden liner. Open valleys are more common on the period homes around Rochester and Chatham, and they rely heavily on the lead holding.

Why They Fail

• Lead cracking — old lead work-hardens and splits along the folds where the valley is dressed
• Lifted tiles — where the tiles were never cut back far enough, water can get behind
• Blocked valleys — moss and debris gathering in the channel, damming water
• Failed mortar — where an open valley was formed in mortar, it weathers away

Why They're Easy To Miss

Valleys are recessed and hard to see from the ground, and the entry point is usually hidden under the tiles at the edge of the channel. Water enters, tracks along battens and drops somewhere else entirely. A valley leak is one of the most common reasons a leak is "fixed" twice and still comes back.

What A Repair Involves

Once the tiles are lifted along the channel, the valley lining is either repaired or renewed in lead, dressed properly to the pitch, and the tiles re-laid and cut back correctly. On period properties we match traditional methods — lime mortar where the original used it, and lead sized to suit the slope. Done properly, a valley repair lasts as long as the lead.

If your leak keeps returning after a repair, a valley is worth a specific look. We survey period roofs across Medway with photographs of exactly what's failing.