The clearest signs a commercial building needs exterior cleaning are visible streaking, algae or mold growth, dirty flatwork, foggy windows, and faded signage — along with practical triggers like an upcoming sale, a new tenant, or simply not remembering the last time it was cleaned.
10 signs it's time to clean
Visible streaking or dark staining
Dark streaks running down a facade, especially below windows or rooflines, are usually mineral deposits or organic staining building up over time.
Algae, mold, or mildew growth
Green, black, or gray patches on roofs, siding, or shaded areas are a clear sign organic growth has taken hold — and it spreads if left alone.
Gum, oil, or tire marks on flatwork
Parking lots, drive-thrus, and loading docks collect grime that only gets more stubborn to remove over time.
Foggy or streaked windows
Windows that look dirty even right after rain usually have mineral buildup or grime that needs more than a squeegee.
Faded or dirty signage
Signage that's harder to read from the road is losing you visibility — and customers — before they ever reach the door.
Musty or mildew odor near entrances
A lingering damp smell near entryways or vents often points to mold or mildew growth nearby.
Customer or tenant complaints
If people are mentioning the building's appearance, it's already affecting how your business is perceived.
An upcoming sale, appraisal, or lease renewal
Exterior condition shapes first impressions for buyers, appraisers, and prospective tenants.
New tenant move-in or seasonal reset
A clean exterior is an easy way to mark a fresh start for a new tenant or a new season.
It's been over a year since the last cleaning
If you can't remember the last time the building was cleaned, it's probably time.
Match the sign to the right service
Streaking & Staining
Usually softwashing for roofs/siding, pressure washing for flatwork and masonry.
Which method?Algae & Mold
Softwashing kills growth at the root instead of just removing what's visible.
SoftwashingDirty Windows
Streak-free exterior window cleaning, including high-rise glass by drone.
Window CleaningHard-to-Reach Areas
Tall or oddly shaped facades that lifts and scaffolding can't access.
Drone CleaningCommon questions
What's the most common sign a building needs cleaning?
Visible streaking or dark, patchy staining on the facade is usually the first thing people notice — often followed by green, black, or gray algae growth on roofs and siding.
Can dirty windows really affect my business?
Yes. Foggy, spotted, or streaked windows are one of the fastest ways a building reads as neglected to customers and tenants, even if everything else is well maintained.
Should I clean before a sale, appraisal, or lease renewal?
It's one of the best times to do it. Exterior condition affects first impressions for buyers, appraisers, and prospective tenants — and it's a relatively low-cost way to improve how the property presents.
How do I know if it's pressure washing or softwashing I need?
It depends on what you're seeing and where. See our guide on Pressure Washing vs. Softwashing to match the symptom to the right method, or just reach out and we'll assess it.