Black mould is a toxic fungus that grows in moist environments. With a dark, slimy or spotty appearance and sometimes also a foul odour, black mould can cause numerous respiratory health problems. Window sills provide an ideal environment for black mould to grow, especially when water builds up on them. Clean black mould from your window sills with chlorine bleach to kill the spores and prevent them from coming back.
Fill a bucket with 4.5 litres (1 gallon) of warm water, add 125 ml (1/2 cup) of bleach and 50 ml (1/4 cup) of washing powder. Put on rubber gloves and a breathing mask to prevent exposure to the mould spores.
Open the window to ventilate the area while cleaning, and to reach all of the mouldy areas.
Dip a sponge or cloth in the cleaning solution, and wring it out. Wipe the window sill and all mouldy areas with the cloth or sponge. Rinse the cloth or sponge in the bucket as needed. Allow the solution to sit for 15 minutes.
Dampen a clean cloth or sponge with warm water and wring it out. Wipe the window sill with the cloth or sponge to remove any cleaning solution.
Dry the window sill with a towel.
Keep the window sills as clean and dry as possible to prevent mould growth.