Humidity that never quite leaves
Between Norfork and Bull Shoals, the air here holds moisture longer than it does inland. North-facing walls and shaded soffits stay damp, and that is exactly where algae and mildew take hold first. It is the single most common reason a Mountain Home house looks dirty on one side and clean on the other.
More glass than the average house
Lake houses are built to look at the water, which means tall window walls, second-storey glass and doors that never get reached with a household squeegee. Those are water-fed pole and ladder jobs, not a bucket-and-rag afternoon.
Shade from mature hardwoods
Tree cover keeps a roof from drying out after rain and drops debris into gutters twice a year. Both shorten how long a clean roof stays clean, which is why an annual wash usually makes more sense here than waiting until it looks bad.