Roof valleys leak because they work the hardest. A valley channels water from two roof slopes into a single line, so any weakness along that line lets water find its way inside. Common faults include cracked lead or GRP valley linings, slipped or cut tiles, failed underlay and blockages from moss and leaves. The good news is that most valley leaks can be fixed properly once the cause is identified early.
Common reasons roof valleys leak
Valleys vary by material and build, but the failure points are often similar:
- Debris and moss build-up that dams water and makes it back up under tiles
- Cracked, split or perforated lead where it has fatigued or been trodden on
- UV and temperature movement causing GRP or fibre cement troughs to fracture
- Cut tiles along the valley edge slipping or breaking, which exposes the lining
- Underlay deterioration so wind-driven rain bypasses the tile cover
- Poor detailing where the valley meets a chimney, dormer or flat roof
- Old mortar on valley cuts cracking and washing out
- Nail fatigue or corroded clips allowing movement along the valley line
On older Midhurst properties with clay tiles or natural slate, valleys may be narrower and more sensitive to leaf fall. Mortar-bedded cuts are common and need careful renewal, or an upgrade to a modern valley trough or properly dressed lead for longer life.
How to spot valley problems early
Look for these warning signs without climbing on the roof:
- Stains on ceilings or walls that follow a diagonal line beneath a valley
- Drips or damp after heavy rain, especially on the side of a loft
- Daylight visible at the valley when you look from the loft
- Moss, twigs and leaf build-up in the valley channel
- Cracks or perforations in visible lead, or splits in GRP troughs
- Broken or slipped cut tiles along the valley edge
- Overflowing gutters where the valley discharges
Use binoculars from the ground for a safer look. If you suspect a leak, call a roofer rather than walking on or near the valley. Valleys concentrate loads and are easy to damage underfoot.
Valley repairs done the right way
Every roof is different, but a sound process prevents repeat leaks:
- Inspection and tracing. Lift the affected tiles, check the underlay, battens and valley support boards. Trace water tracks to their entry point, not just where you see the stain.
- Temporary stop if needed. In wet weather a temporary emergency repair can be applied to halt water ingress, then a full repair is scheduled in dry conditions.
- Clear the channel. Remove moss, leaves and silt so water can run freely.
- Renew damaged fabric. Replace split lead or cracked GRP troughs, swap broken or slipped cut tiles, and repair underlay and battens where rotten.
- Detail junctions. Rework leadwork and flashing at chimneys, dormers and abutments so laps, clips and seal lines are correct.
- Test and tidy. Water test where possible, refit tiles neatly and clear gutters so discharge is free.
We handle roof repairs, leadwork and flashing, chimneys, gutters, fascias and soffits, as well as flat roofs where valleys meet dormers or extensions. If a valley failure is part of wider roof fatigue, we also advise on new roofs with options matched to local materials.
Local advice for Midhurst homes
Midhurst sits in the South Downs National Park with the River Rother running through the town. Shaded valley sides and higher humidity encourage moss, which traps moisture in roof valleys. Autumn leaf fall from trees in and around Easebourne and Fernhurst can block valley channels and gutters in days. Many period cottages and older town properties use clay tiles or slate that need careful cutting and support at valley lines, and chimneys in Midhurst White brick often sit close to valleys so the flashing detail is critical.
After South Downs storms, check valleys for slipped cuts and debris. Rural homes and outbuildings around Petworth, Lodsworth and Cocking can be more exposed, so wind-driven rain pushes water across valleys harder than in calmer conditions. For local help with Roofing Midhurst, we are your nearby team of roofers near Easebourne, Fernhurst and Petworth.
When to call a roofer
- Call immediately if water is dripping or staining is growing quickly after rain. We provide 24-hour emergency roof repairs in Midhurst and can apply a temporary stop.
- Book an inspection if you see moss build-up, cracked lead or slipped valley cuts.
- Schedule seasonal checks before winter and after heavy leaf fall to keep valleys and gutters clear.
Do not remove tiles or walk in the valley yourself. A trained roofer has the right access, fixings and materials to prevent further damage.
Why choose Midhurst Roofing
- Five generations of family know-how with valleys, leadwork and tiled roofs common to Midhurst
- Own trained team, not subcontractors, with Director Paul Watson overseeing quality
- Free inspections, free advice and free no-obligation quotations
- 24-hour emergency service for leaks, with temporary emergency repairs where needed
- Price Match Guarantee on like-for-like quotes
Get a free inspection and quote
If you suspect a valley leak, the sooner you act the smaller the repair is likely to be. For free advice or a free, no-obligation quote, call Midhurst Roofing on 01243 278007. If your roof is leaking, ask about the 24-hour emergency service.
How long does a valley repair take?
Most straightforward valley repairs are completed in a day once the area is dry and safe. Complex junctions with chimneys or dormers may take longer, especially if underlay or battens need renewal.
Can a leaking valley be repaired in wet weather?
We can apply a temporary emergency repair to stop water ingress in wet weather. A permanent fix is best carried out in dry conditions so materials bond and seal correctly.
How often should valleys be checked?
At least once a year, plus after major storms and after autumn leaf fall in areas with overhanging trees. Regular gutter clearing helps valleys discharge water freely.