How to clean algae off bricks?

[dmarty]

Hi all, 

Outside of villa complex we have an exterior brick wall which has this ever growing black/green fungus. The wall is old but in good shape otherwise and no cracks whatsoever. We considered a gerni or pressure cleaner, however the water pressure could very well blast away the mortar holding the bricks together. Its an old wall.

I'm curious if anyone else has dealt with this...

Any recommendations on how to remove or clean it?

[MitchellMc]

Hi @marty,

A typical D.I.Y. pressure washer usually won’t blast away mortar unless it’s already crumbling. They also have fine streams, so if you're concerned, you could take the time to target just the bricks while avoiding the mortar as much as possible. If you'd rather not risk it, you could consider hiring a professional who specialises in soft washing with chemical treatments. Any outdoor cleaning specialist should be able to assess the condition of the mortar and recommend the safest approach.

Another option is to periodically spray the area with 30 Seconds 5L Roof Treatment Concentrate. While designed for roofs, it can also be used on brick walls. This type of treatment works by killing the growth, which then breaks down and washes away over time. Since your wall has a heavy buildup, this process could take a while.

If you’re keen to handle it yourself, I’d suggest picking up a Gerni and testing a small section first to see how the mortar holds up. Otherwise, a professional can ensure a thorough clean without causing damage.

Please let me know if you have any questions.

Mitchell

[dmarty]

Thank you. I'll give one of those methods a go.