I need some advice. We are moving so I borrowed a power washer (home unit) to clean the outside tiles and walls. It works great on algae and dirt, but some of the paint is coming off the walls.
This is nothing new: About a year ago I noticed the stucco/paint flaking off in a few areas, especially where it had been applied directly to concrete.
The house will be repainted, but I’m not sure how to proceed on cleaning:
a) Dial it back, because a power washer is strong enough to damage paint,
or
b) Let the paint come off. A power washer is NOT strong enough to remove paint that is sound, so the stuff that is coming off should be removed before repainting, anyway.
Opinions?
Janet
Edited 6/18/2008 5:50 pm by jyang949
Replies
Dial it back, because a power washer is strong enough to damage paint,
Powerwashers are definitely strong enough to strip paint - which is why they are not recommended for use on painted surfaces.
I've pressure cleaned thousands of houses and well bonded paint doesn't come off unless you get the tip too close. Get a chemical injector with the pressure washer, mix a couple of cups of automatic dishwasher powder with hot water in a 5 gallon bucket. Soak one wall at a time with the injector tip then go back and rinse from the top down. Keep the tip several feet away from the house unless there is a tough spot then move closer slowly. If the paint is already peeling the pressure washer will keep it peeling until it gets to a well bonded area but it's a bad practice. Use a putty knife on those areas.
Thanks for the tip about the dishwasher powered soap. What other surfaces does that work well on? What soap do you recommend for a pressure washer on auto paint and other painted metal surfaces.
It works great on vinyl and aluminum siding and pretty much everything else I've ever tried it on. I wash the windows on my house with a car wash brush and a bucket full of Cascade then I go wash the cars with whats left. Sometimes I add a little Dawn just so I can see where I've washed since Cascade makes no foam. Don't get the dry powder on your car since it can remove the paint.
Don't get the dry powder on your car since it can remove the paint.
Thanks for the warning. I think I'll try Simple Green first.
Janet - are you dealing with painted surfaces older than 1978 and if so, have you tested for lead paint?
Jeff
The house was built in 1990, so lead paint isn't an issue.
Same as was said . Power washing takes a lot of paint off that needs scraped but it hits the bonded and thats the line of going on and not causeing damage . You scrape that little bit before you paint with scrapers and putty knifes that are sharp.
On an old house they are a whizz taking so much paint off you would have been doing by hand.
You have to wait a few days to let it dry before you finish preparing and paint . Always prepare what you will paint that day or you will be looking at more the next morning.
Tim