How To Clean A Tin Roof. Use a pressure washer, which can loosen shingles and seriously damage your roof. Cleaning mould on tin roof.
Soak your cloth or sponge in the water/detergent mixture. This is the best way to clean a roof if you have asphalt shingles. Spray your roof down with wet & forget.
Keep the flow of the water running down the roof instead of upward.
Once each panel is clean, rinse it immediately with clean water to prevent streaks and film. Terne, an alloy of lead and tin, was also used as a plating material. Wet the roof with clean water, then spray the cleanser over the metal surface, beginning with the darkest areas of the roof. To assist in making up the solution, table 1 below shows the dilution required for different strength bleaches to give a 2% solution.