House Washing in Thunder Rock, Kuna, Idaho

Short Throw Means Violent Splash

A sprinkler covering a large lawn arrives at a wall as a gentle mist with most of its energy spent. A Thunder Rock head sitting a few feet from the siding arrives with force, striking the soil at the base and throwing mud upward in a defined band across the lower siding. That band contains soil, the dissolved mineral from the untreated Boise-Kuna canal water, and whatever was on the ground, and it dries into a crust rather than a film. It is the most pronounced lower-wall soiling we see anywhere in the city.

Field Soil Makes the Crust Harder

Homes on the outer rows back onto working ground toward Black Cat, and coarse agricultural soil bound into wet canal mineral makes a tougher deposit than either alone. A soft wash handles it because the solution breaks the bond rather than trying to knock the particle off, which matters because high pressure on a gritty crust drags that grit across the vinyl surface and dulls it into a chalky patch that no later cleaning restores. Interior-row homes have mineral without much grit and are a simpler job.

Small Houses Make This Affordable

Thunder Rock plans run 1,217 to 1,874 square feet, genuinely compact by current Kuna standards, and house washing prices on actual wall area at $0.18 per square foot. Small footprints and modest heights mean the total wall area here is among the lowest in the city, so a full house wash is a realistically small number. That matters, because the splash band on these houses warrants doing more often than a larger home would need, and the pricing makes that practical rather than theoretical.

Pocket Park Homes Get Organic Growth

Thunder Rock includes pocket parks, walking paths and green space on an HOA of about $270 a quarter, all irrigated with untreated canal water. Homes facing a pocket park get more moisture against the wall and more shade from planting, which is what allows algae and mildew to establish on north-facing siding. That is growth rather than dirt, it does not rinse off, and the solution in a soft wash is what actually addresses it.

Soft Wash Versus Pressure Wash, Plainly

House washing is a soft wash at $0.18 per square foot: low pressure, correct solution, chemistry doing the work. Pressure washing at $0.20 per square foot is for the driveway, the path and the patio, where high pressure is genuinely the right tool. Using the pressure washer on the siding would drive water behind the laps into the wall assembly with no route out, and on a young house that is a problem you discover a year later.