Exterior wall painting

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In the next few weeks, I am going to paint the outside walls of my house with masonary paint but, before this, I have to sort out some fine mould/algae. They are hardly noticeable but can someone tell me the best way to treat it? I could wire brush them but that would probably leave some roots.

Any guidance would be appreciated.

[Astral Voyager]

These only grow in damp conditions so try and eliminate any causes of the wall failing to dry out such as overhanging trees, or shrubs.

Use a stiff (not necessarily wire) brush to remove what you can. Then either:

1. Apply a mix of 1 part household bleach to 4 parts water solution to the wall. Leave 48 hours and then wash off with clean water.
2. Apply a propriety fungicidal solution and follow the instructions on the tin.

If the original growth is severe (which from your post doesn't appear to be the case) you may need to repeat the application.

Mel.

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This is not a particularly damp wall and gets much afternoon sun but will follow any advice given.