The Bunnings Workshop community can help with your home improvement projects.
If you plan to paint a wall that has mould, you can clean it with Flood 750ml Mould Action Pre-Paint Treatment and then add some Protite 20ml Mould Defender Paint Additive to your paint. This will help prevent the mould from coming back.
However, you need to address the underlining issue, trapped moisture in the room or wall. Moisture absorbers can be helpful if placed within the room.
I've found a quarter teaspoon of oil of cloves in a litre of water is a great way to kill and prevent mould on most surfaces. Through my experience, it has been more effective than bleach-based products and is kinder on the lungs. - MitchellMc
Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects