The Simple Answer: Once a Year for Most Homes
For a typical Maryland home, an annual exterior wash is the baseline. That single cleaning removes a year of pollen, mold spores, road grime, and algae growth before it has time to set in and damage surfaces.
But "typical" isn't one-size-fits-all. Several factors significantly affect how often your home needs professional cleaning.
Factors That Mean You Need More Frequent Cleaning
These conditions typically point to washing every 6–12 months:
- ✓Heavy tree canopy overhead (constant organic debris, moisture, algae)
- ✓North-facing exterior walls (less sun = more mold and algae)
- ✓Near a busy road (elevated dust and exhaust buildup)
- ✓Light-colored siding (shows staining much earlier)
- ✓Humid, low-lying property (accelerates biological growth)
- ✓HOA or rental property (appearance standards)
Surface-by-Surface Guidance
Different surfaces have different timelines:
- ✓House siding: 1–2x per year
- ✓Driveway and walkways: 1x per year, or after heavy winter salt use
- ✓Deck and patio: 1x per year before season, re-seal every 2–3 years
- ✓Roof: every 2–4 years (soft wash only)
- ✓Gutters: 1–2x per year
- ✓Fences: every 1–2 years depending on material
Frequently Asked Questions
Algae and mold become more embedded over time and harder to remove. Paint can be stained permanently. Organic growth on concrete can cause pitting. Regular annual washing is much cheaper than delayed restoration.