A gutter that only fails in heavy rain is rarely completely blocked. It is usually restricted - the water gets away eventually, just not fast enough when the roof is shedding at full rate.
Partial blockage
Silt and moss compacted into the bottom of the run cut the effective depth. In drizzle there is room; in a downpour the run fills and spills at the lowest bracket.
This guide sits under our Gutter Cleaning & Clearing work, covering 20-mile radius of Plymouth.
Fall and bracket sag
A run that has dropped between brackets creates a pond in the middle. Water sits, weight increases, the sag deepens, and each storm overtops the same spot.
Outlet and downpipe capacity
One 68mm downpipe serving a long run of steep roof will be overwhelmed in a South West squall. Clearing helps; if it still overtops, the answer is an extra outlet, and we will say so rather than sell you repeat cleans.
Questions we get on this
- Can you tell which cause it is?
- Usually, yes - camera footage of the run plus a flush test shows whether it is debris, fall or capacity.
- Do you re-fix sagging brackets?
- We can re-seat loose brackets. Replacing rotten fascia is a builder's job.
- Is it worth doing before winter?
- Yes. Most overflow damage happens in the first autumn storms after leaf fall.
Related reading
- Landlords: exterior maintenance that prevents claims
- Limited budget: what to clean first
- Best time of year for exterior cleaning in the South West
- Gutter vacuum or ladder clearing?