Mold is a common substance, particularly in damp or humid climates, and it can spread and grow on any solid surface area, including sidewalks, decks, driveways and brick. Mold spores disperse quickly and grow rapidly, creating a potential safety risk if left unattended. Cleaning green mould from a brick surface is possible with some tools available from most hardware stores. Note that you should wear protective clothing and gear, including eye and respiratory masks, when dealing with any sort of mould.
Saturate the mould on the brick with a mould cleaner or weed killer.
Allow the substance to sit on the brick for several hours or longer, if the weather is warm and dry.
Dip a stiff brush into water and scrub away the dried cleaning solution and the mould from the brick.
Repeat the application of the cleaning solution and the scrubbing until the mould has been thoroughly removed from the brick surface.
Clean away any mould on the brick as soon as it appears with a damp, stiff brush to help prevent it from spreading. Drying the brick surface after it gets wet can help deter the growth of mould as well.