We never put high pressure on a tile or shingle roof. Not dialed down, not on a wide tip, never. High pressure cracks tile, strips the protective granules off asphalt shingles, drives water where it should never go, and it can void your roof warranty. It also does a poor job. Blasting shears the visible growth off the top and leaves the organism alive underneath, primed to regrow.
Soft washing works differently. We apply a cleaning solution at low pressure and let the chemistry do the work. The solution kills Gloeocapsa magma, moss and lichen at the root. Dead growth releases its grip and rinses away, and the heavier moss and lichen lighten and shed over the following weeks instead of being torn out with roof material still attached.
Because the organism is dead rather than trimmed, a soft washed roof stays clean two to four times longer than a roof that was pressure blasted. That is the whole argument in one sentence. Kill it and it stays gone. Blast it and you have already booked the same job for next year.
Tile gets extra care. Clay and concrete tiles crack under concentrated point loads, which is exactly what a careless boot delivers. Our crew uses walk pads and load-spreading technique, placing weight across multiple tiles at their strongest points, and we plan every pass so we walk the roof as little as the job allows. It is slower. It is also why broken tiles are not part of how we work, and why we are comfortable on the kind of roofs other companies turn down.
