Why do Manchester driveways turn green and black so quickly?
Manchester is a wet city, and damp air is exactly what algae, moss and lichen like. A drive in shade beside a terrace wall, under a tree or between two semis can go green within a single winter. Tarmac tends to turn dark and patchy, block paving gets slippery and weeds push through the joints.
Common local problems include:
- Green algae on shaded block paving that stays damp.
- Moss in the joints between blocks and along kerb edges.
- Leaf stains and tannin marks from nearby trees.
- Oil and tyre marks where cars park every day.
- Dull grey concrete that has built up years of traffic film.
A green drive is not only untidy. A wet algae film can be a slip risk on a slope or on the short path to your front door.

