Pressure wash or scrub stucco?

The paint on my stucco on concrete block house is chalky and peeling and even cracking in a couple of places. Everyone here, in south Florida, seems to pressure wash stucco before painting, but I am wondering whether scraping then scrubbing with bleach and detergent would be just as effective.
Here's a link, hopefully, that shows the cracking paint:
http://i51.tinypic.com/16hte2f.jpg
The stucco has what is referred to as a smooth finish, though I've also heard it called a sand finish. But it's basically pretty smooth, especially with several layers of old paint on it.
If a pressure wash is the way to go, what power of washer would be necessary to clean it up?
If scrubbing would work, what kind of mixture would be best?
Thanks.
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wrote:

I have a 2700 PSI 3GPM washer and I use the 40 degree nozzle so it is a wide fan spray that knocks down the power quite a bit but goes fast. Be careful with too much power. It will eat that stucco right off the wall.
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On 3/10/2011 12:12 PM, snipped-for-privacy@aol.com wrote:

My 2,000 psi machine might too. It ate concrete facing off tar treated block.
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On 3/10/2011 12:12 PM, snipped-for-privacy@aol.com wrote:

Pressure washing is the only way to go...you want to remove not only dirt, but loose paint. You want also to pay attention to weather...allow at least two days of dry weather after p.w. and before painting. You should prime any areas that clean down to bare stucco.
Our condo was painted by a contractor and had had badly peeling paint with a lot of mildew under the paint...probably not p.w. before the previous paint job. The contractor sprayed the walls with bleach solution before pressure washing, which seemed odd to me but worked out to a very satisfactory job. We had loads of loose paint blasted off by pressure washing and we devised a pretty neat system for capturing all the paint debris for disposal. I had used bleach previously (1:10 with water) to clean bad mildew from behind some plants, with no damage to plants or lawn - just rinsed it well, no major deal. Prior to the painting, my husband and I repaired quite a few damaged spots on the concrete block/stucco...corners knocked off by mowers, block broken away around dryer vents, etc. We used latex stucco patch (sanded), using two coats if the defects were larger...our stucco was more textured and I made the patches match by hitting them with a bristle scrub brush. If you need to patch, it's pretty easy to use and scrape away until you are satisfied. That was 2001, and it has held up very well. Our bldg. was about 40 y/o, and quite a few fine cracks in the stucco, and contractor used brushable caulk to cover those prior to painting...much easier that smooshing with your fingers if there are a lot of cracks.
You may also want plastic tarps to cover landscaping with, but have to be sure to remove tarps right away so plants don't get burned.
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THE ANSWER IS YES, NO, MAYBE, ABSOLUTELY, POSITIVELY, NEVER, MAYBE, AND I DON'T HAVE A CLUE.
There are MANY different variations of stucco, and if I could deduce your particular type and problem, I would be working for the NSA at roughly $5 million a year.
Stucco is applied in stages.
Each stage's integrity depends on the stage before.
There are different stages, some being just sand, concrete, colorant, or some binder, such as an acrylic or some adhesive outside the parameters of sand, concrete, and whatever they throw in there.
Once you want to "clean" such stucco, it can come apart with the ease of a fingernail pulling off one layer from another.
So, it is an equation that has variables.
If you have a loosely adhering level of stucco, you will find out really quickly when you just blow a 3' x 3' hole in your stucco.
Easy is the best approach.
Scrubbing can take off flimsy surface coatings as fast as a power washer.
The trick is to find out what you're working with, then deal with that.
Don't go at it with a power washer, or you will quickly find out if you have a soft vulnerable area or stucco.
HTH
Steve
Heart surgery pending? Read up and prepare. http://cabgbypasssurgery.com www.heartsurgerysurvivalguide.com
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On 3/10/2011 7:20 PM, Steve B wrote:

Pressure washing stucco/concrete block is SOP in Florida...standard, routine. Yes, it's possible to etch your name in concrete with a pressure washer, but one quickly realizes they are too close or have the pressure set too high. I definitely would not use it on wood, as it turns the wood to fuzz. The stucco I'm familiar with has some texture...not the deep troweled texture, but sanded or a bit more than that (dabbed with a brush)....there is no way to get loose paint off such a surface unless one picks it piece by piece. With all the retirees in Florida, none has enough time left to resort to that :o)
I would take pains to pick/dig dried caulk joints and repair them, as well as searching out any other gaps (plumbing and/or electric entries) to caulk them - around hose bibs, dryer vents, etc. Those who want a coat of paint below grade can just blast away with the p.w. (pro's do it), dig a little ditch whilst they clean the masonry; prime bare masonry, paint, throw the dirt back in....the color goes down to soil level.

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yo wrote:

I had my central Florida house painted last summer. The guy pressure washed it first, bit of chlorine added, no idea of what power. I was flabbergasted at how well stuff cleaned up! Especially the soffits, home to myriad spiders and webs and old mud nests from mud daubers; the latter, especially, are nearly impossible to get off by scrubbing. Sooo...if I were you, I'd hire it done. Cost me $250 for about 4,400 sq.ft. of surface.
I suspect the peeling paint in your photo would come off from the PW' if not, it should be scraped off.
Another advantage of PW - I assume your house is on slab, being in Florida - is that it can be used to dig down 6-8" around the walls so they can be painted below ground level.
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Thanks for that.
Yes, it's on a slab. But that reminds me. In some areas around the house, the ground has settled revealing bare block that didn't receive any stucco when the house was built. There is no indication of any water damage or seepage inside, but I am thinking that this should be sealed somehow, whether by applying stucco to it or some kind of sealer? Any thoughts on that?
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yo wrote:

A. Paint it
B. Add sand (Florida dirt) so it hides the unstuccoed part
No point in sealing it, water goes in and out all the time. Bet your slab isn't sealed :)
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Chalking is not normal for Latex, I would take samples to a pro paint store to see what you have, Oil chalks and the Chalk must be removed, Stucco chalks. Dont just think latex paint and a quick wash is best, you could make a bigger mess.
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On Thu, 10 Mar 2011 20:03:53 -0800 (PST), ransley

Latex paint will chalk from the sun down here in Florida. We just finished repainting our community picnic shelter because of that. The South side went bad (H/D Behr exterior paint)
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