Soft washing the whole exterior, and why it comes back.
Quick answer: House Washing and Soft Washing. Southeastern Renovation is a licensed South Carolina general contractor (CLG.127339) serving the Charleston Lowcountry and York County, SC. Work is coordinated by Southeastern Renovation as the general contractor. Licensed trade subcontractors handle work requiring their trade credentials; permit responsibilities depend on the project scope and jurisdiction. Call (843) 718-8177 for an estimate.
Humidity, shade and still air are what feed it, which is why the north elevation and anything under trees goes first while the sunny side stays clean for years. That is not uneven cleaning, it is uneven growing conditions.
A soft wash kills the growth rather than removing the visible part of it, which is the difference between a house that stays clean for a season and one that stays clean considerably longer.
It is also the cheapest way to find out what is going on with your exterior. Whoever is washing it is at close quarters with every elevation, and failing caulk, soft trim and lifting paint are all visible from there.
Serving Charleston, Mount Pleasant, North Charleston, Summerville, Goose Creek, James Island, West Ashley, Isle of Palms, Moncks Corner, Hanahan, Ladson, Daniel Island, Johns Island, Park West, Seabrook Island, Kiawah Island, Edisto Island, Folly Beach, Ravenel, Rock Hill, Fort Mill, Tega Cay, Lake Wylie, Clover, York, Indian Land across the Charleston Lowcountry. Part of Southeastern Renovation.
More often than in a dry climate, and unevenly — the shaded north side needs it long before the sunny side does.
It is a maintenance cycle rather than a one-off, and the interval depends on shade and airflow more than on the calendar.
Because the conditions that grow it never really go away. A wash that only removes the visible growth leaves what it grows back from; killing it is what buys the longer interval.
It should be, and that is a question worth asking rather than assuming. Rinsing and protecting planting beforehand is normal practice, not an extra.