Power Washing

Green-gray film on the siding. Dark streaks running down from the gutters. A walkway that’s gone slippery in the shade. That’s dirt, mildew and algae, and it washes off. Inside Out Painting power washes homes in Denville and across Morris County.

What gets washed

• House siding: vinyl, wood and aluminum
• Driveways and decks, when they’re part of the job

How the surface is protected

Pressure is the part that does damage, and more of it isn’t better. Water at high pressure can drive behind siding, lift wood grain, strip a painted surface and cut into soft mortar. What Inside Out Painting does instead:

• washes with biodegradable detergent and bleach to remove dirt, mildew and mold
• hand washes delicate areas
• gives the house time to dry before anything else happens

The order is the point: a cleaning solution lifts mildew and algae, so the pressure doesn’t have to. And the drying time is not a formality, because wood and siding hold water after a wash, and paint over a damp surface fails early.

What washing will and won’t fix

A wash takes off what’s sitting on the surface: dirt, pollen, mildew, algae and the gray film that builds up on siding. It won’t fix what’s underneath. Paint that’s already peeling will come off faster under a wash, not stick better. Wood that’s soft or rotted needs repair, not cleaning. Rust streaks, and the brown bleed that comes out of cedar, may fade rather than disappear. Which of those you’re looking at decides whether this is a cleaning job or a painting one.

Power washing or soft washing?

The surface decides how much pressure a wash can take. Soft washing uses low pressure and lets the cleaning solution lift mildew and algae, which suits painted surfaces, older wood and anything fragile. Higher pressure belongs on hard surfaces like concrete and pavers. Our article on the difference between power washing and soft washing explains which method each surface needs, and what is safe to power wash covers siding, brick and decks.

Washing before painting

Washing is step two of Inside Out Painting’s exterior painting process, before any scraping or priming. Paint won’t stick to a surface covered in dirt, chalk or mildew, and painting over it is a common reason a job peels early. If you’re planning an exterior painting job, the washing is already part of that work.

Plenty of washes have nothing to do with painting, though: before a party, before the holidays, or before a house goes on the market.

Common questions

How often does a house need washing?

It depends on shade, tree cover and which side you’re looking at. North-facing walls and anything under trees hold moisture and grow algae first, so they come back sooner. The signs are visible: how to know when your home needs power washing walks through them.

What time of year is best?

Mild, dry weather, with enough warmth left in the day for the house to dry out afterward. The best time of year to power wash in New Jersey covers when to schedule it.