POWERFUL CLEANER TO KILL & PREVENT GREEN GROWTH, ALGAE & LICHEN GROWING ON ROOF TILES, TARMAC, BRICKWORK DRIVES & PATIOS. Green Clear is a green growth killer and cleaner that has been formulated specially for the purpose of killing green growth on all different types of roof tiles. tarmac, drives, patios and brickwork. It is used in a multitude of scenarios, not only to initially kill green growth, but also on an ongoing basis to help with prevention. It will remove growth usually after one heavy application. It works equally effectively as a roof green growth remover, green growth killer for tarmac and green growth remover for patios.