How Often Should You Clean Your House Siding in North Carolina?

North Carolina's humidity, pollen, and mature tree canopy make our siding one of the fastest-fouling in the country. But cleaning too often is a waste of money — and pressure washing when soft washing is called for can actually shorten your siding's life. Here's the honest schedule we recommend to Triangle homeowners.

The default schedule by siding type

• Vinyl siding — soft wash every 12–18 months
• Fiber cement (HardiePlank) — soft wash every 18–24 months
• Painted wood or cedar — soft wash every 12 months
• Stucco — soft wash every 18–24 months
• Brick — pressure or soft wash every 2–3 years

Six signs your siding needs cleaning now

• Green film on north or shaded elevations
• Black vertical streaks below gutters
• Yellow pollen coating that survived spring rain
• Cobweb buildup around eaves and vents
• Spider or wasp activity at soffits
• That chalky, dull look under bright sunlight

Why the schedule matters

Algae and mildew aren't just cosmetic — they hold moisture against the siding and, on painted or wood surfaces, accelerate paint failure and wood rot. A $400 soft wash every 18 months is dramatically cheaper than a $12,000 siding replacement 6 years early.

DIY vs professional soft washing

A garden-hose bleach mix will kill surface algae, but it rarely reaches the root and it rinses away long before it can work. Professional soft washing uses a calibrated solution ratio, longer dwell times, and low-pressure application designed to protect landscaping — usually with a real cost-per-year that's competitive with DIY once you factor in equipment rental and time.