The default: 12–24 months
If you don't have any of the conditions below, every 18 months works. That keeps your siding clean enough that buyers and appraisers don't notice it, and prevents mildew from setting in deep enough to require chemistry-heavy restoration.
Wash annually if any of these apply
- Heavy oak canopy — Fair Oaks, Orangevale, Carmichael, Curtis Park, parts of East Sac and Land Park, Loomis. Oak pollen is brutal on stucco and painted siding.
- North-facing shaded walls. Mildew thrives in shade and prevailing moisture. North-facing walls in any older Sacramento neighborhood are at higher risk.
- Foothill-edge properties — El Dorado Hills, Cameron Park, Folsom east of the canyon. More rain, more moss, more biological growth.
- Multi-family / HOA exteriors. Curb appeal value depreciates fast across multiple units.
- Commercial / storefront. Quarterly to biannual is more common than annual here.
Stretch to 24+ months if
- Newer master-planned community with minimal tree cover (parts of West Roseville, Sun City Lincoln Hills, newer Anatolia in Rancho Cordova).
- Single-story with no shaded walls.
- Modern Hardie or fiber-cement siding (more resistant to mildew than older painted wood or stucco).
- You're already on annual gutter, solar, or driveway maintenance — those clean a lot of the visible surfaces incidentally.
What happens when you wait too long
Two things start happening past the 30-month mark on a typical Sacramento home:
- Mildew and algae penetrate into the paint or stucco. Removal then requires longer dwell times, stronger chemistry, and sometimes a second pass — increasing cost.
- Pollen and dust become embedded in the surface texture. A standard wash leaves a residual haze instead of a clean reveal.
Homes that go 5+ years without a wash often need a 2-visit job: first visit to break down the buildup, second visit to do a proper clean. That costs more than just doing the annual maintenance.
The real cost of skipping years
A Sacramento house wash is typically $200–$400 annually. A 5-year deep restoration is $700–$1,200 — 3-4 years of annual maintenance compressed into one expensive visit, plus you spent 5 years looking dirty.
Annual maintenance is the cheap option. The expensive option is waiting.