What happens if you leave it
Tiger-stripe staining
The vertical black streaks down the face of every white gutter are airborne particulates bonded with rainwater run-off. They don't wash off in rain — they need agitation.
'My house looks tired'
Most people blame the render or the roof. It's usually the gutter line. Cleaning it transforms how the whole property reads from the road.
Wrong methods damage UPVC
Aggressive jet-washing or harsh chemicals can dull, oxidise or pit white UPVC. Specialist soft cleaning lifts the dirt without harming the plastic.
Pre-sale stress
Estate agents flag dirty gutters in photographs because buyers do. Cleaning them is the cheapest pre-marketing improvement you can make.