Green or mouldy wall: why wash it before winter
Walls and fences are the first thing you see of a house, and also the first to turn green. On the north-facing side, with watering or trees nearby, the green and the black stains come back every winter.
Why wash in autumn
- It removes the green before the rains, when it grows fastest
- Stone and render still dry quickly on mild days
- If you are painting in spring, the wall is already prepared (see washing before painting)
What you can do at home
On low walls and short stretches, a brush, water and a pH-neutral anti-moss product do the job. Work from top to bottom and rinse well.
What to avoid
- Acids and neat bleach on granite and painted render
- Maximum pressure with the nozzle close up: it strips paint and joints
- Washing a wall with peeling paint without telling whoever paints it next
Granite, render or blocks
Each material needs a different pressure and product. On granite the usual problem is green algae on stone; on painted render, green and mould on the facade.
How much it costs
Wall and fence washing costs from €6.5/m², with an €89 minimum per visit. The guide price shows in the site calculator in 60 seconds, with no prepayment: you pay at the end.