A quick clear-out of leaves and debris sometimes solves the problem entirely, and it's the right first step every time. But if the actual cause is a split in the lead liner or tiles cut too tight to the water channel, clearing debris alone buys a season at best — the same overflow returns in the next heavy storm, because the material failure or restriction that's actually responsible hasn't been touched.
A repair that holds treats clearing and inspecting as step one, not the whole job, and only replaces the valley material once it's clear that's genuinely what's needed.
The sequence a proper repair follows
- Clear all debris from the full length of the valley and the gutter it feeds into, working from safe roof access equipment rather than a ladder alone.
- Inspect the valley lining closely once it's clear, checking for splits, corrosion, or areas where the lead or liner has lifted or moved out of position.
- Check where tiles meet the valley edge for over-tight cuts that restrict the water channel, and open these up to the correct clearance where needed.
- Where the lining has genuinely failed, replace it with correctly sized lead, properly lapped at joints to shed water down the slope rather than trapping it.
- Check the roof structure directly beneath the valley for existing timber damage from past leaks before closing the roof back up, since rot found at this stage is much cheaper to deal with than rot found later.
Why clearing debris on its own often isn't enough
Debris is frequently a genuine contributing cause, but it's rarely the whole story where overflow has been happening repeatedly. A valley that's marginal for the roof area it drains, or that has a split liner, will keep struggling in heavy rain even when perfectly clear — the debris just made a borderline situation worse rather than being the sole cause. Treating clearance as a complete repair when there's an underlying material or sizing issue means the same failure returns at the next serious storm.
Why an undersized valley needs more than a repair
Where inspection shows the valley genuinely can't carry the peak flow from the roof areas feeding it — rather than being blocked or split — patching or replacing like-for-like doesn't solve the underlying problem. That situation calls for widening the valley or reconsidering how the roof planes drain into it, which is a more significant piece of roofing work than a straightforward repair, and worth discussing properly rather than fitting a replacement that will overflow in exactly the same way next time it rains hard.
Interfaces with the roof structure
If timber below the valley has already suffered water damage from previous leaks, that has to be addressed as part of the same job — treating or replacing affected timber before the roof covering goes back on, rather than sealing a repaired valley over structural damage that's still there.
Work on a valley almost always requires proper roof access equipment and, depending on height and pitch, safety measures for anyone working at height — this isn't a job to approach with a ladder propped against the gutter.
How you know the repair has worked
The genuine test of a valley repair is performance during the next period of sustained heavy rain — the loft beneath should stay dry and no water should track down the internal wall that previously showed staining. Because a proper repair replaces failed material and clears any restriction rather than just removing surface debris, it should hold through storms of similar or even greater intensity than the one that first revealed the problem.
Common questions
How often should a valley gutter be cleared?+
Roughly annually for most roofs, and more often where there's overhanging vegetation shedding leaves and debris directly into the valley. Regular clearing reduces the chance of debris masking or worsening an underlying issue.
Is lead always the right material for a valley repair?+
Lead remains a standard and reliable choice for valley linings when correctly sized and lapped. The key isn't the material alone but that it's specified and installed to suit the actual roof area draining into it.
Can a valley repair be done without disturbing the surrounding tiles?+
Some clearing and minor inspection can be done with limited disturbance, but replacing a failed lining properly usually means lifting tiles either side of the valley to lap the new material correctly under them.
Get a written repair quote
We clear, inspect and only replace what's actually failed, with a written quote before any roof work begins.