The honest answer: most North Jersey homes need a soft-wash every 12 to 18 months — sooner if you’ve got north-facing siding under heavy tree cover. Skip it longer than two years and the green-and-black streaks you’re seeing aren’t dirt. They’re mildew and algae feeding on the siding itself.
The simple seasonal schedule
- Late spring (May–June): Wash off winter salt spray, leftover pollen, and any black streaks that settled over winter. This is the single most-important wash of the year.
- Late fall (October–November): Optional but smart — clears tree sap, leaf tannin, and spider activity before everything freezes in place.
- Mid-summer touch-up: Only if your home faces a busy road or you’re hosting an event. Most homes don’t need it.
Signs you’re overdue
- Black or green streaks running down from the gutter line.
- White siding looking grey from a distance.
- A chalky residue on your hand when you swipe the siding.
- Visible spider webs and wasp activity in soffits and corners.
- You haven’t had it washed since you moved in. (You’re overdue.)
What kind of wash actually works
Forget the rented pressure washer. North Jersey homes — vinyl, painted wood, fiber cement, stucco — need a soft-wash: low-pressure water mixed with a mildewcide that kills algae down to the root. Pressure-washing strips paint, drives water under siding, and the streaks come right back in three months because nothing was killed, just rinsed.
What does it cost?
Most single-family homes run $400–$800 for a full soft-wash, depending on size, story count, and condition. Larger Victorians and estates are quoted on-site.
One thing to remember
Mildew is not just ugly. It eats finishes. Every season you wait, more of your siding’s surface gets damaged — and re-painting or re-siding costs 50× what a wash costs. That’s the whole reason this matters.
Have a question we didn’t cover? Our crew answers the phone during business hours — (201) 514-5382 — or grab a free written quote on the contact page.
