Water Running Down Walls From Gutters
Rainwater should travel along the gutter and down the pipe, never down the face of the wall. If you see water sheeting down brickwork or render during rain, or dark wet patches that take days to dry, something in the rainwater system is letting water escape. Left alone, it can lead to stained walls and damp inside.
Where the water is coming from
Stand back during rain and trace the water to its source. Water spilling over the front of the gutter means it is full or overwhelmed. Water running straight down behind the gutter suggests it has moved away from the roof edge or sits too low. A stream from one spot below a joint usually means a failed seal.
Each of these has a different fix, which is why pinning down the source matters.
Blocked gutters
The most common cause is simply a blocked gutter. Leaves, moss and silt fill the channel, so water rises and spills over the edge. Outlets are a frequent pinch point; a single blocked outlet can make a whole run overflow.
See our blocked gutters page for how this is cleared.
Gutters that miss the water
If a gutter has dropped, been knocked out of line or was fitted too low, water coming off the roof may land behind it or overshoot it. The water then runs down the fascia and the wall beneath. This often shows as staining directly below the gutter line along its whole length.
Re-aligning the gutter and replacing brackets usually solves this.
The link to damp walls inside
Brickwork that is soaked repeatedly can carry moisture through to the inside, especially on solid walls without a cavity, which are common in older houses. Damp patches high on internal walls, near ceilings or around window heads can be linked to an overflowing or leaking gutter outside.
Damp has many possible causes, so a gutter problem is one thing to rule out rather than the only explanation. If you have internal damp, mention it when you contact us.
Other signs of persistent overflow
Green algae streaks on render or brick, flaking paint on window sills, washed-out mortar joints and splash marks at the base of the wall all suggest water has been running down for a long time. In winter, icicles or ice on the ground below a gutter tell the same story.
Our render cleaning guide covers staining on rendered walls.
What we do
We clear the gutters, free the outlets and check the downpipes, then look at the joints, brackets and alignment with the channel empty. Minor repairs such as resealing joints, replacing brackets and correcting the fall can be quoted separately for you to approve.
Before-and-after photographs show the condition of gutters you cannot see from the ground.
Solid walls and cavity walls
Many older houses have solid brick or stone walls with no cavity. These are more likely to carry moisture through to the inside if they are soaked repeatedly. Cavity walls are designed to resist this better, but persistent wetting can still cause problems around openings.
Knowing the age and construction of the house helps put any internal damp in context.
Downpipes leaking onto the wall
Water on a wall is not always from the gutter itself. A cracked downpipe, a loose joint in the pipe or a pipe that has come away from its brackets can spray water onto the brickwork. Look along the length of the pipe during rain.
Our downpipe unblocking page explains how blockages in pipes can cause leaks at joints.
Splashback at ground level
Where a downpipe discharges onto the ground rather than into a drain, or a gutter overflows onto paving, water can splash back up the base of the wall. This can leave dirt marks and keep the lower wall damp.
Check that downpipes discharge where they should, and that gullies at the bottom are not blocked.
Next steps
Send a photograph or short video of the water running down the wall, ideally during rain, plus a wider shot of the gutter. Note any damp inside and where it appears. Use the form on this page, WhatsApp or call for a free quote.
Our leaking gutters page has more on tracing leaks.
Get a free quote
Send a few details and ground-level photos if you have them. We will reply with honest advice and a free, no-obligation quote.
Frequently asked questions
Can blocked gutters cause damp walls?
Yes, persistent overflow can soak brickwork and contribute to damp inside, particularly on solid walls. It is one possible cause to rule out.
Why is water running down behind my gutter?
The gutter has usually moved away from the roof edge or sits too low, so water misses it. Re-aligning it usually helps.
Will cleaning the gutters stop the wall getting wet?
If a blockage is the cause, yes. If a joint or alignment is the problem, a minor repair may be needed too.
How do I know if damp inside is from the gutter?
Damp near the top of a wall or around a window head, directly below a faulty gutter, is a common pattern. Damp has many causes, so rule others out too.
Pristine Roof Cleaning Solutions is based in Petersfield, covers Hampshire · Surrey · Sussex and is fully insured to £5,000,000 public liability.
Related guides
- Gutter Overflowing: Causes and What to Do
Gutter overflowing in heavy rain? Identify blocked outlets, sagging runs, joint leaks and downpipe problems, with safe checks and the right next step.
- Gutter Repairs: Leaks, Sagging and When to Replace
How to fix a leaking gutter joint, a sagging run or a dripping downpipe joint, which faults are quick repairs and when the gutter needs replacing.
- Stained Fascias and Soffits Below Gutters
Green or black stains on fascias and soffits usually mean water is escaping from gutters. What the marks tell you and how the cause is fixed.
Last updated 2026-11-03.