A mouldy wall is caused by moisture and lack of air flow. These conditions make it inevitable that mould will grow in your home. The moisture can be a result of a plumbing leak or it may be entering the home from the outside.Once you have determined the cause and stopped the supply of moisture, the mouldy wall must be repaired. Fixing a mouldy wall requires some effort, but is worth it to have a wall that does not show the signs of a mould problem.
Pull furniture away from the mouldy wall and open windows in the room to allow air flow. Use a box fan to move air over the affected area. Dry the wall thoroughly for a day or two.
Mix water and bleach in a spray bottle using a 50-50 ratio.
Spray the bleach mixture on the affected area of the wall and wipe it with a rag. Remove as much of the mould as you can using this method.
Cover the affected area of the wall with a stain blocker using a paint brush. Let the stain blocker dry for a day and apply a second coat if any signs of staining can be seen. Let the second coat dry for a day.
Paint the repaired area of the wall with touch-up paint that matches the rest of the wall. Apply the paint using a paint brush.