A conservatory is the part of a house you look at from the inside, which is exactly why a dirty conservatory roof is so noticeable. It is also the surface that gets neglected longest, because you cannot reach it and the box gutter behind it is out of sight.
Why they get dirty so fast
Conservatory roofs sit at a shallow pitch, so debris does not shed. Polycarbonate has a soft, slightly textured surface that holds algae. And most sit under the shadow of the main roof, catching everything that washes off the tiles above — grit, moss fragments and leaf litter.
What a proper clean covers
Cleaning the panels alone is half the job. A complete conservatory clean includes:
- The roof panels — glass or polycarbonate — softwashed and rinsed with pure water.
- Glazing bars and end caps hand-detailed, because that is where the black staining sits.
- The box gutter between the conservatory and the house wall cleared and flow-tested.
- Frames, cills and downpipes cleaned back to white.
- Finials, ridge and flashing checked while we are up there.
Why no pressure washing
Pressure forces water past the seals and into the roof void, and it can craze polycarbonate and dull the surface so it dirties faster next time. We use a low-pressure chemical clean, pole-fed pure water rinsing and hand detailing on the bars.
The box gutter is the important bit
The gutter between the conservatory roof and the house wall is the most common source of conservatory leaks. It is narrow, shallow, and it catches everything from the main roof. Once it silts up, water backs up under the flashing and appears as a damp patch on the wall inside. It should be cleared every time the roof is cleaned.
How often
Annually for most Kent properties. Under trees or on a heavily shaded north-facing aspect, twice a year keeps it looking right. It is a natural pairing with the annual gutter clear, since we are already set up for the same elevation.
The short version
- Shallow pitch plus plastic panels means fast algae growth.
- Glazing bars and the box gutter matter more than the panels.
- Never pressure wash a conservatory roof.
- Annual cleaning, ideally alongside the gutter clear.
