For an acid solution, mix nine parts clean with one part muriatic acid. Always pour the acid into the water. Rinse the wall thoroughly with clean water from top to bottom and make sure all the cleaning solution has been removed. Pressurized Water T o save time and labor costs, many contractors use pressurized water to clean new masonry. The base unit can be 100 feet away from the units being cleaned if long hoses, pressure guns and special nozzles are used.
Some systems have two hoses, one for water and the other for cleaning solutions.
If not used carefully and within reasonable boundaries, water pressure cleaning can damage masonry. The sand finish on some units can be removed entirely by water pressure, resulting in a wall that look different than its designer intended. Nozzle pressure in excess of 700 psi may damage brick units and erode mortar joints. Note that pressurized cleaning probably will change the appearance of sand molded brick, brick with glazed coatings and sand-faced extruded brick. Obtain the cleaning equipment and cleaning solution and test them on sample areas.