# Help needed diagnosing ripples in Stucco



## Tom Struble (Mar 2, 2007)

wouldn't the wire tend to hold that all down Lone?


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## loneframer (Feb 13, 2009)

tomstruble said:


> wouldn't the wire tend to hold that all down Lone?


I'm not sure I understand the question T, but I'll try.

One layer of felt under the wire. The felt behind the browncoat, scratchcoat, basecoat, whatever you chose to call it, will draw the moisture out of the product and wick it through. "Variable permiability".:whistling There generally will be a bond created between the felt and cement. The second layer of felt provides the very necessary "drainage plane" between the sheathing and the stucco.
If the OSB wants to expand and buckle, the wire will provide little resistance.


I have to wonder though, if the paper wasn't attached firmly to the sheathing, as well as the wire, it is possible that the paper could expand, as we know occurs with moisture, forcing some movement in the surface before the material set up. ???


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## Tom Struble (Mar 2, 2007)

no i understand 2 layers for sure [no tyvek:notworthy]
every time i saw hard coat stucco done they nail the hell out of the wire
now wouldn't that tend to hold down the paper,i mean i understand the felt rippling somewhat but that much?Unless they only fastened the wire in between the studs,wouldn't that kind of thing show up after the scratch coat?


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## loneframer (Feb 13, 2009)

tomstruble said:


> no i understand 2 layers for sure [no tyvek:notworthy]
> every time i saw hard coat stucco done they nail the hell out of the wire
> now wouldn't that tend to hold down the paper,i mean i understand the felt rippling somewhat but that much?Unless they only fastened the wire in between the studs,wouldn't that kind of thing show up after the scratch coat?


 My concern is that the installer only stud nailed the wire. You know what it's like trying to nail into OSB or plywood between layouts. I'm assuming it was hand-nailed. I like to attach the wire like luann underlayment, nail/staple the p!$$ out of it.

I've done a few jobs where felt and wire was applied over bare studs and stuccoed, with surprisingly good results, so this looks like a sheathing issue to me more than anything, but what do I know.:blink:


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## Tom Struble (Mar 2, 2007)

you know stuff!!!:w00t:


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## Rob Scheer (Feb 19, 2010)

It is a monolithic slab and I'll have to check if the buckling extends past the sheathing...

Assuming it is a sheathing problem and the OSB warped from the initial trapped moisture (I wouldn't be surprised if they used tyvek but don't know). Wouldn't my suggestion of applying fiber mesh and bedding it with Primus, than applying an elastomeric coating be an acceptable solution to level the wall and fill cracks? Barring any further moisture intrusion, I wouldn't think the OSB would continue warping or am I mistaken?


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## loneframer (Feb 13, 2009)

Rob Scheer said:


> It is a monolithic slab and I'll have to check if the buckling extends past the sheathing...
> 
> Assuming it is a sheathing problem and the OSB warped from the initial trapped moisture (I wouldn't be surprised if they used tyvek but don't know). Wouldn't my suggestion of applying fiber mesh and bedding it with Primus, than applying an elastomeric coating be an acceptable solution to level the wall and fill cracks? Barring any further moisture intrusion, I wouldn't think the OSB would continue warping or am I mistaken?


 If the sheathing is solid and the wall was prepped and wired properly, my opinion is that it is solid enough to go over. I'm dying to know what the underlying cause was though. You said you had limitted access from the garage? How do the seams look on the OSB? Do they look like there is pressure on the butts? Can you put a straightedge from stud to stud on the back of the sheathing? Maybe there will be a tell-tale hump in the OSB.


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## Tom Struble (Mar 2, 2007)

i don't know ,how can you ever be sure of something like that,may end up putting good money in to something that may not work,but i don't know from stucco

old sayin in the siding bidness..no matter what you cover sh*t with it's still gonna stink


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## loneframer (Feb 13, 2009)

Another thought. Is the OSB hung in a "standup" configuration? The strength axis is designed to run perpendicular to studs and will buckle much easier if it runs parallel to the studs. We used to sheath with standups using 1/2" CDX and buckling between studs was typical when it got wet and expanded. It could only be worse with OSB.


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## brickstretcher (Dec 18, 2009)

what I've seen here in the Chi area is the peps that do it is osb then tywrap their foam board and skim coats. Probably why we don't see 2 much of it anymore is 2 many fly by nighters(gotta luv a Rush plug!!!)


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## Rob Scheer (Feb 19, 2010)

Update to answer some of your questions:

The buckling and cracks do not extend past the OSB, where it meets the mono slab there are no cracks at all...

Inside the garage where I can view the OSB, there is no detectable hump. It appears to be flat against the straight edge. At least at this one spot. I could see staples penetrating 1/8" though OSB with about a 6" spacing.

Unfortunately, I could not see the seams of the OSB.

I drilled a small hole and I'm 100% certain Tyvek was the barrier used...
*
*


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## Tom Struble (Mar 2, 2007)

well Rob what are you trying to accomplish?Why it did this,or if you can stucco over it...i don't understand


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## Rob Scheer (Feb 19, 2010)

I was trying to determine the cause so I can recommend the appropriate repair. Tear it out and replace may not be necessary...


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## Tom Struble (Mar 2, 2007)

i got it:thumbsup:guess really your the only one that could judge that


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## oldfrt (Oct 10, 2007)

I have a friend in Florida that discovered that some of his stucco had the mesh nailed directly to the studs.
No ply.
Maybe the ply you are seeing in the garage was for lateral strength.
How's the stucco look where you can see the ply?


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## Rob Scheer (Feb 19, 2010)

tomstruble said:


> i got it:thumbsup:guess really your the only one that could judge that


Noooo, it's suppose to be a group effort


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## Rob Scheer (Feb 19, 2010)

oldfrt said:


> How's the stucco look where you can see the ply?


It's identical to the rest...


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## oldfrt (Oct 10, 2007)

I've seen some weird stuff used for sheathing.
In Texas,I saw 1/2" homote used as siding.
It was battened to replicate more substantial,but you could punch a hole in it easily with the slightest pressure.

It looks like a visual inspection after cutting through is the real way to find the problem.
Everything else is just guess work.


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## thom (Nov 3, 2006)

I've seen that many times. It shows up more when using the two coat (brown then color) stucco because it is a thinner stucco. any unevenness in the walls will show up. Generally it's not noticeable unless the sun is at a long angle. 

If it's what I've seen, it's the result of the sheathing not being flat. Things that can cause this, fiberboard sheathing is number one (oftentimes used in conjunction with osb or ply) but any sheathing that bows will cause this. It is more likely on walls framed at 24" OC because the sheathing bows easier. 

It's not just moisture that can cause sheathing to bow. Direct sun can heat up the panel enough to cause it to bow, generally toward the inside of the house. 

If this is the problem, there really is no problem except aesthetics. If you really want to make it flat, re-lath and stucco.


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## CanCritter (Feb 9, 2010)

could always throw in some cultured stone to break up some of the panels in a archetectual way so you dont have the long stretchs...you could use some wood paneling to..caan see where it would look nice if it was done with right style


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