Greater Boston's mix of humid summers, road salt, and shaded triple-decker siding creates perfect conditions for green algae and black mold on vinyl, wood, and composite decks. Annual exterior washing isn't vanity — it extends paint life and prevents rot on porches in Jamaica Plain, Somerville, and Quincy.
DIY pressure washing works for concrete driveways and some siding if you use the right tip (often 25° green) and keep the wand moving — never zero-degree tips on wood or shingles. Too much pressure etches brick, forces water behind vinyl, and splinters cedar decks. For two-story siding or soft stucco, hire a pro with proper ladders and insurance.
Best timing: late April through October, after pollen season and before first frost. Avoid blasting window seals, electrical panels, or AC condenser coils. Decks often need a low-pressure wash plus brightener, not raw PSI. Many Boston landlords schedule move-out pressure washing between tenants — a fast way to recover security deposits.
Not sure if your siding needs wash or replacement? Snap a photo on Opa Pro for a free quote in 30 seconds and a fair local price range from vetted pressure-washing pros in your ZIP.