Block wall stuccoing

[Steve B]

I want to do some very simple stucco over block. I will pour a footer with rebar, let it dry, first course it, then build the blocks in an asymmetrical Southwest pattern with openings, and rolling top. I want to just put some stucco over that, probably tinted.

Questions:

Do I mix stucco myself, or buy premix? Do I need a plain layer of lath over the block first? Or a layer of wet uncolored scratch coat stucco and a layer of cloth imbedded, then let dry, then a topcoat of colored? I want something that will last the longest without popping off in chunks due to our temperature swings from 15 F to 115 F, and the wet/freeze/dry cycles of rain/ snow, baking sun.

Thanks in advance.

Steve

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[Uno]

Steve, I'm looking at the same questions you are somewhat. What is your location? (If it's AZ, don't worry, I'm not coming over to celebrate the enactment of civil rights with y'all.)

I don't think summers are going to be getting cooler in the southwest, so I'm hoping to be the pig that wolf or sun can't do in.

Cheers,

[Reno]

The blocks will have an invisible coat of bond breaker that made it easy to get them out of the molds. That's a very light oil that will prevent a good bond of the stucco onto the blocks if you don't clean it very well. I use TSP because it doesn't leave a residue - make sure you rinse well after. All of your suggestions are good and will work. A very good modification is to use acrylic admix instead of water or at least a 50/50 mix of water and admix. The admix improves the stickiness and helps with freeze cycles. I did two 8' x 10' planters- clean like crazy, rinse like crazy, damp the blocks but not wet (no free water at all), one coat colored stucco and one coat top coat. Cloth and lath is not required and will cause looseness later if the cloth is not totally saturated which is almost impossible. So leave it out. Any voids would be places where water will enter and freeze and expand and loosen the stucco.

[Oren]

My last house had stucco over block walls. No lath or cloth.

See: (six steps with list of tools)