Dryvit or stuccoflex directly over CMUs.
averagejoe
| Posted in Construction Techniques on
Does anyone have any experience with something like dryvit or stuccoflex as a direct coating over CMUs? I have a project where we are taking down an old failing lime brick chimney and I’m wondering about rebuilding it with 4″ CMUs with flush struck joints and then covering it with a thin textured color coat. I think dryvit makes a product specifically for direct application over CMUs and I would guess that others do as well. I trust my mason to do a nice flat job with the block laying.
But of course, just because someone makes a product for something doesn’t mean it’s a great idea. It does seem silly however to go through the work and expense of lathing and scratch/browning just to get a concrete surface over the top of a concrete surface.
Replies
you dont have to lath concrete block. real stucco will mate with concrete block without wire. as long as there is no paint.
If the surface is relatively flat and smooth, would you recommend a scratch / brown coat first, or could we just do a sand texture color coat over the CMUs, much like a parge coating over foundations?
The CMU surface is different than the joint and so the coverage would be different. The CMU would telegraph through the finish coat. It's just not that thick. Doing a parge before the color coat would make it even. Depends on the results you're looking for.
I apologize if these are simple questions, but how thick a coat do you think would be needed? If it's primarily for smoothing and evening out the surface, would 1/4 - 3/8" do? And I'm assuming we should let it fully cure before applying a color coat, similiar to a scratch / brown coat?
it depends on how bad the block was laid and what type finish coat, I did two coats on my block.
Just curious - it sounds like you have a mason, so why doesn't he do the parge coat and finsish the job for you?
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My mason is (at least I think) a very competent stone and block layer, and he will do parge coats on foundations, but for whatever reason, he just never has gotten into doing finish coatings. I likely will hire out the finish coatings as well, but since I currently don't have a "go to" guy for it that I trust, I'm trying to gather as much information on possible options and what things to watch out for as possible before I start interviewing potential subs.This has always been a great forum for me to sort thorough lots of different opinions and advice on aspects of a project that I haven't had a lot of experience with yet. I guess I'm just trying to build my base of information so that I have some ability to judge whether someone I may hire really knows what they're talking about. Thanks all.
You have the wrong screen name then. Someone like you who is everlearning, will never be an average joe. You keep rising to the top of the pile.Be well
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That would be best answered by someone at tech support at Sto or Dryvit. This forum's participants probably cannot steer you as well as the experts there.
I have seen Sto's "flex" product used for just the application you have in mind, but I don't know the specifics of the application.
I'm actually hoping to see a rep for one of these companies at tomorrow's JLC live here in minneapolis. If none are exibiting, I'll give em' a call on friday. I like to come here first so I have a clue about what questions to ask them and have some basis for judging what they will tell me. It seems that for every sales rep that is very upfront about their product's limitations in certain applications, there is another that thinks their product is the greatest thing since sliced bread for everything.