A surprising share of the damp problems we get called to are not roof leaks. They are gutter problems, and they have often been running for years before anybody notices, because the water is going down the outside of the wall rather than the inside.
How it happens
Gutters fill with leaves, moss washed off the roof, and grit from the tiles. Once the outlet is blocked, water backs up and finds the nearest low point, usually a joint. From there it runs down the wall. Brick and render absorb it, the wall never fully dries out, and eventually the damp shows on the inside face, typically in a corner or under a window.
The signs to look for
- A vertical stain or green algae streak down the outside wall, always in the same place.
- Plants growing in the gutter, which means there is enough silt in there to hold soil.
- Water sheeting off the front edge of the gutter during rain rather than running along it.
- A downpipe that stays dry while the gutter overflows.
Clearing is only half of it
Clearing a gutter fixes today. If the gutter has the wrong fall, or a joint has opened, or the brackets have dropped, it will block again next autumn because water is standing in it rather than moving. Worth checking while somebody is up there: the fall towards the outlet, the condition of the joints, and whether the fascia behind is sound or has started to go.
How often
Once a year is enough for most properties. Twice a year if you have mature trees close by, which describes a good deal of Sidcup, Bexleyheath and the older parts of Maidstone. It is cheap work that prevents expensive work.
