A damp patch high on an upstairs wall has a limited number of external causes, and they cost very different amounts to put right. Working out which one you have first is worth an afternoon.
Gutter first, because it is simplest
If the patch worsens during rain and sits below a gutter run or joint, clear and flush the gutter before anything else. A large share of suspected roof leaks are overflowing gutters.
This guide sits under our Gutter Cleaning & Clearing work, covering 20-mile radius of Plymouth.
Wall saturation
Heavily algae-covered, water-retaining render on a wind-driven elevation can hold enough moisture to show internally. Cleaning and drying that elevation often reduces it noticeably.
When it is a roof or builder's job
Patches that appear after wind rather than rain, or that sit under a valley or chimney, are usually a covering or flashing defect. That is a roofer, not a cleaner, and we will tell you plainly.
Questions we get on this
- Can you diagnose damp?
- We can rule out gutter and surface causes with camera footage and a flush test. We do not carry out damp surveys.
- Is it worth cleaning the wall if there is damp?
- Often yes, but only after the water source is confirmed. We would rather you spent the money in the right order.
- Do you charge to look?
- Quotes are free and in writing.
Related reading
- Moss on roof tiles: when it matters and when it does not
- Lichen on roofs and copings: the slow damage nobody sees
- Slippery patios: why they get dangerous and what fixes it
- Red and orange staining on block paving