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How to get rid of green mould on outside walls

Mould can make your outside walls look unsightly and might even be a health hazard. So how do you remove it? Well, you’ve found a good place to start with our how to get rid of green mould on outside walls guide!

Step 1 Cleaning

Before we can do much else the best place to start is by cleaning as much of the green mould off the walls as possible.

It is always advised to wear a respirator for something like this, you will be knocking a lot of spores into the air which can be dangerous. But hey I’m not your mother, do what you want.

For cleaning the walls you can use a pressure washer if you have one, but this is not always advisable as you can knock the mortar out of brick walls which just creates another job for you.

If you want a more gentle approach just use a scrubbing brush and bucket of warm soapy water to clean the green mould off. Once clean we can start to think about killing the mould.

Home Made Ideas

If you want to kill the green mould using something from your cupboard under the sink then here are a few ideas for you.


Bleach will always work well for these kinds of jobs. It just kills everything, I mean it is pretty toxic stuff after all.

Mix some bleach with water and scrub onto the walls with a brush. Just make sure you are wearing scruffy clothes, you don’t want to go getting bleach on anything nice.

Vinegar Solution

If you want something a little less aquatic life-destroying then Vinegar apparently works well. This is not something I have tried myself but I have heard lots of good things.

Mix some vinegar with warm water and put it into a spray bottle. Spray the vinegar solution all over the green mould and let it sit for a couple of hours before rinsing off with warm water.

Purchasable Items

We live in a modern world, with modern solutions for problems like this. So if you want the easy way out then you can always make your way over to Bezo’s place and buy something off the virtual shelves.

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08/11/2022 10:23 am GMT

There are tons of products like the above available. Just spray them on and let them get to work.

Call me old fashioned but I don’t like introducing a ton of chemicals into my garden so prefer to use old fashioned methods. but if you want to take the easy way out I’m not going to argue with you, I really can see the appeal of these kinds of products.

Keeping The Green Mould Away

So once you have killed off the mould how do you prevent it from simply coming back? Well if you use one of these sprays then they tend to offer quite a bit of protection from the green mould coming back, sometimes up to 12 months.

But what else can you do?

Masonry Paint

If you paint the outside wall with a green moss problem with masonry paint then you be preventing it from coming back, at least for a while.

This is because masonry paints contain fungicides and herbicides designed to stop plant and fungal growth on them.

No one wants to paint the outside of their house white only to find it green in a year, so it makes sense that manufacturers try to stop this from happening.

These weed and fungal killers are one of the main reasons I don’t recommend you use masonry paint inside.