Winchester properties have three different valley types across different housing eras. The repair approach is completely different for each.
Valleys concentrate rainwater from two roof slopes into a single channel. In Winchester's above-average rainfall climate, a valley carries more water per unit area than any other roof element. When a valley fails, the volume of water entering the roof structure is significant — and the failure point is frequently misidentified because the water travels laterally before appearing internally.
Original lead valleys are the standard on Victorian, Edwardian and 1930s Winchester properties. A code 5 lead tray runs along the valley channel, with cut tiles on both sides trimmed to a margin of 65–75mm from the valley centre line. The lead is clipped to allow thermal movement — not nailed through the face.
Lead valleys on Winchester pre-1945 properties are now 80–100 years old. At the correct specification (code 5, correctly clipped), lead valleys last 60–80 years — meaning most original Winchester lead valleys are at or approaching end of life. The failure modes are: joint failure between lead lengths, chase failure where the lead is set into masonry, and thermal fatigue where lead has been incorrectly fixed without movement allowance.
Repair: re-dressing (reforming sound lead that has lifted) costs £150–£350. Full replacement in code 5 lead: £450–£900 depending on length.
Concrete interlocking tile roofs on Winchester's post-war estates (Stanmore, Winnall, Harestock, Boyatt Wood in Eastleigh) typically have mortar valleys. The cut tiles on both sides of the valley are bedded in mortar, filling the valley channel. No lead tray beneath — the mortar is the primary waterproofing.
As the roof moves in thermal cycling, the mortar cracks. Once cracked, water tracks down the mortar channel and into the roof. Most mortar valleys on Winchester post-war properties are now showing cracking — either at individual joint positions or across the full valley run.
Repair: repointing open mortar joints: £150–£350. Full mortar valley re-bed: £250–£500. Conversion to lead valley on re-roof: add £300–£500 to the re-roof cost.
Open valley tiles — proprietary half-round or channel valley sections in a matching tile profile — are used on modern properties and some re-roofs from the 1990s onwards. No mortar, no lead — the valley tiles channel water into the visible open channel. Self-cleaning and low maintenance.
Open valley tiles are only available for current concrete tile profiles. They cannot be used with clay plain tiles or natural slate — where lead is the only appropriate specification. For modern concrete tile Winchester properties, open valley tiles are an excellent long-term choice.
Failure mode: rare — open valley systems are robust. The main issue is debris accumulation in the channel, which is cleared on routine maintenance visits.
Free valley survey across Winchester — call 01962 809171.
Many Winchester properties have multiple valleys — hipped roofs in Weeke, Chandler's Ford and Oliver's Battery may have four valley junctions. When a ceiling damp patch appears, identifying which valley is the failure source requires systematic elimination rather than guessing from the damp patch location.
The diagnostic process: from the loft during rain, trace the water back from the drip point to the entry point. The entry point may be a cracked felt section, a failed valley lead at a specific joint, or water tracking from a valley edge that has lifted. If the loft is inaccessible, we identify the failure from the ground and ladder survey by assessing each valley's condition and matching it to the damp patch geometry. In nearly all Winchester valley failures we survey, the failure point is identified within the first visit and confirmed with photographs before quoting. Call 01962 809171 for a free valley survey and diagnostic visit.
We carry out free surveys and provide written condition reports across Winchester and all surrounding Hampshire areas. NFRC registered, fully insured, 10-year written guarantee on all work. Same-week appointments available. No call-out fee on any survey or daytime visit.
Call 01962 809171 or email info@winchesterroofers.co.uk. We respond to all enquiries within one working day.
We carry out free surveys and provide written condition reports across Winchester and all surrounding Hampshire areas. NFRC registered, fully insured, 10-year written guarantee on all work. Same-week appointments available. No call-out fee on any survey or daytime visit.
Call 01962 809171 or email info@winchesterroofers.co.uk. We respond to all enquiries within one working day.
We carry out free surveys and provide written condition reports across Winchester and all surrounding Hampshire areas. NFRC registered, fully insured, 10-year written guarantee on all work. Same-week appointments available. No call-out fee on any survey or daytime visit.
Call 01962 809171 or email info@winchesterroofers.co.uk. We respond to all enquiries within one working day.
Lead valley: pre-1945 clay tile or slate properties. Mortar valley: post-war concrete tile estates. Open valley tiles: modern and some recently re-roofed properties. We confirm at the free survey.
Interior damp patch 1–3 metres from the valley position, water appearing in gutters on one side after rain but not the other, or visible debris accumulation at the valley outlet. Valley survey is the definitive answer.
Yes — conversion to lead valley on re-roof adds £300–£500 to the job cost but eliminates the cracking cycle that affects mortar valleys. We include both options in Winchester re-roof quotes where mortar valleys are present.
Code 5 (2.24mm, 25kg/m²) as the BS 6915 minimum for valley linings. Never code 3 or 4 in a valley position. We specify code on every Winchester valley replacement quote.
Correctly specified code 5 lead valley: 60–80 years. This is the expected lifespan on a Winchester property where installation follows BS 6915 and Lead Sheet Association guidance.
No call-out fee. No obligation. Written condition report.
01962 809171