Can blocked gutters cause damp?
Yes, and it is one of the more common causes of damp that gets blamed on something else. A blocked gutter pours water down the same section of wall every time it rains.
Brick, render and mortar can cope with weather. What they cope with far less well is being repeatedly saturated in one spot with no chance to dry out.
How it happens
Water overflowing at a joint runs down the face of the wall instead of into the downpipe. Over a wet winter, that section of wall never dries, and moisture works through to the inside face.
The internal damp patch usually appears close to the affected corner, often at ceiling level upstairs or behind a chimney breast.
Signs to connect the two
- An internal damp patch that worsens after heavy rain rather than gradually
- Green algae or a dark vertical stripe outside in roughly the same position
- Peeling paint or blown plaster on the inside face of an external wall
- A musty smell in a room next to an external corner
- Staining on the fascia or soffit above the affected area
Clearing it is the first step, not the whole answer
Once the gutter runs properly the wall can begin to dry, but that takes time and the internal damage does not repair itself.
If the overflow has been going on for a long time, or the damp does not improve once the wall has had a dry spell, it is worth having someone look at the wall itself. Clearing gutters is honest work with obvious limits, and we will say when something is beyond it.
Want it looked at properly?
Send a few photographs of the elevation along with the address, and Rob will tell you what can realistically be improved, what it will cost and when it can be done.