Can tile and shingle be cleaned with the same solution?

The Asphalt Roofing Manufacturers Association (ARMA) writes its algae solution for asphalt shingle, liquid household bleach and water, and its technical bulletin closes the subject with one sentence: “Other cleaning chemicals or methods should not be used without the approval of the shingle manufacturer.”

Read forward, that sentence puts any change to the chemistry on a shingle roof in the shingle manufacturer's hands. Read the other way, it describes a solution written for one material. Nothing in it offers the mix to a roof made of something else.

ARMA's own two documents do not print one mix. The technical bulletin says directions for mixing may vary among shingle manufacturers and depend on the amount of discoloration, while ARMA's separate algae and moss page names a 50:50 mix of laundry strength liquid chlorine bleach and water. That tension is ARMA's to resolve, and it is set out under why the method page prints no bleach ratio.

Eagle Roofing Products, a concrete tile maker, begins somewhere else. It recommends only water for a tile roof cleaning, and allows a cleaner only when how dirty the roof is, or what pollutant is on it, calls for one.

Even then the cleaner comes with two conditions: the most diluted solution possible, and one that should be compatible with concrete, because Eagle writes that some products can affect the pH of the tile or even etch the surface. Eagle also writes that the algae, mold and mildew on concrete tile are not harmful to the integrity of the tile, and that “concrete tile roofs are exceedingly cleanable.”

Those lines are written for concrete, so they apply as written to soft washing flat concrete tile and to soft washing barrel tile made of concrete. A clay tile takes its cleaning chemistry from its own maker.

GAF, a shingle maker, publishes its own mixture for its own shingles in its 2024 technical advisory bulletin: water, bleach and a cup of TSP or an acceptable phosphate-free substitute, applied with a garden sprayer and rinsed with low-pressure water.

So one material already has two published recipes, ARMA's and GAF's, which is the situation ARMA's own clause anticipates when it says mixing directions may vary among shingle manufacturers. A recipe that changes from one shingle maker to the next has no published footing for a move onto tile.

No association or maker read for this answer publishes a sodium hypochlorite percentage for soft washing, and none publishes a surfactant specification, so there is no common figure to split between a shingle roof and a tile roof.

Metal adds a third recipe rather than a shared one. The Metal Roofing Alliance starts with a garden hose; if water alone is not enough, it names 1/4 cup of mild detergent per gallon of water, left to stand 5 to 10 minutes before a plain-water rinse. Each roofing body writes chemistry for its own material. The full list of published ingredients is under what is in a soft wash solution, and each maker's cleaning limits sit side by side in the roof cleaning page's tile, shingle and metal comparison.

Where a property has both materials, the published record answers roof by roof: the shingle's chemistry from the shingle manufacturer, and the tile's from the tile maker.

Chemistry is not the only shingle limit either. ARMA warns that scrubbing friction may loosen and remove granules, part of cleaning a shingle roof without losing granules.

For a free estimate, the form's project details field is the place to name each roof material on the property and, where it is known, the maker of each.