Why is the Siding on My House Turning Green in Spokane?

If you live in Spokane Valley, Liberty Lake, or anywhere around the Inland Northwest, you’ve probably walked out to your backyard, looked at the north side of your house, and noticed a fuzzy green coating or dark streaks creeping up your siding.

It looks like dirt, but it’s actually organic growth—usually a mix of algae, mold, mildew, and moss.

Why Does It Happen Here?

Our local climate is the main culprit. The north side of your house gets the least amount of direct sunlight, meaning morning dew and winter moisture hang around a lot longer. Paired with our humid springs and autumn rains, it creates the ultimate breeding ground for spores floating through the air. Once they land on your vinyl, stucco, or wood siding, they feed on dust and pollen, multiplying fast.

The Big Mistake Homeowners Make

Many people think, "I'll just blast it off with my pressure washer!"

Don't do it. Blasting high-pressure water directly at your siding can force water up behind the panels, rotting your framing, ruining your insulation, or cracking the vinyl. Plus, high pressure only strips the surface; it doesn't kill the microscopic roots of the algae, meaning it will just grow right back twice as fast.

The Safe Solution: Soft-Washing

The proper way to clean siding is with soft-washing. Instead of high pressure, this method uses a specialized, eco-safe cleaning solution applied at garden-hose pressure. It completely kills the mold, mildew, and algae down to the root, gently rinsing it away and keeping your siding clean for much longer—all without risking a single drop of water getting where it shouldn't.

Let Us Handle the Dirty Work

Don't waste your weekend risking a fall off a ladder or accidentally chewing up your siding with a pressure washer.

Call or text Blast Bros at (509) 362-3034 today for a fast, free soft-washing quote. We'll make your home look brand new again!