Clay tile roofs can be easily damaged if cleaned improperly. A low-pressure or “soft wash” cleans dirt and black algae that accumulate on these roofs. Although, it takes more time to clean than pressure washing, which is why roof cleaning services are so valuable.
The tools of the trade include a low-pressure pump that sprays a mixture of 12-14% sodium hydrochloride mixture.
Professionals recommend adding dish soap to help the mix stick to the tiles to achieve the best results. A ladder is necessary and must be repositioned to spray from every angle.
Sodium hydrochloride is caustic to skin and clothing, so homeowners must not spray it into the wind. A proper respirator is required to protect the lungs. Furthermore, sodium hydrochloride breaks down in two weeks, so it’s important to use it quickly. The best storage location is climate-controlled and out of the sun. Finally, saturating the lawn with water protects the grass from sodium hydrochloride.
Safety aside, this mixture is quite effective. It turns white, and the tiles look cleaner in just a few minutes unless the mixture sodium hydrochloride has lost its potency. There are limitations, however. Roofs need to be cleaned every 2 years to avoid permanent damage and discoloration from algae.