Wall mosture issues using manufactured stone veneer
My house was built in the 1970’s in Southern Vermont Mountains. I want to re-build one small section of wall using manufactured stone veneer (MSV) on the lower section with LP Smart siding above. The part of the wall I want to re-build is an above ground wall of a walk out basement. The wall is 2×6 wood framed. The rest of the wall system will all be removed and re-built. I would like to use the Laticrete MVIS system for adhering the MSV. I was thinking about using either Rockwool or dense pack cellulose. The interior wall covering would be mold resident dry wall. The rest of this house is poorly insulated so I am using the “improve but don’t go overboard with insulation” approach as I redo the worst problems. All of the technical details for MSV and MVIS I have seen show a vaper bearer layer between the sheathing and the MSV. My primary concern what detail do I need to do to prevent moisture problems. Will I be ok as long as I don’t use a moisture barrier on the interior wall? Or what to people recommend?
Thanks
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Replies
David,
It seems that Laticrete offers several approaches -- this document shows a few of them:
Laticrete MVIS brochure.
One illustration mentions an "optional drainage mat." (See image below.) Obviously, this system won't perform as well without the drainage mat as it would with the drainage mat.
In other words, I think the answer to the question, "Will the Laticrete MVIS system work?" is, "It depends." You still need (a) good details, including good drainage details and flashing details, and (b) a skilled installer.
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David,
I'm not sure if you are aware of the high number of failures associated with manufactured stone veneer. If you aren't, you may want to read these two articles:
"Adhered Concrete Masonry Veneer - The Next Big Problem in Construction"
"Manufactured-Stone Nightmares"
You definitely want a rainscreen air gap between the mortar bed and WRB. There is a long history that supports this recommendation.
If you use a lath & scratch coat you will have WRB, rainscreen drainage plane, lath, mortar bed. If you use the cement board you still want the drainage gap. WRB, rainscreen drainage plane, cement board. Some detailing resources are at https://www.mtidry.com/hyperspecs?veneer_type_thin_stone
Thank you Martin and Tyler,
While I had not read these articles about the horrors of MSA, I have read enough about water in walls to be concerned as I read through the application details. Plus, LOL, one of the problems, but not only one, that is driving rebuilding this section of wall is that it has an adhered slate cladding over OSB. It was never finished inside (saving grace?) so I know the studs are sound and only the OSB needs to be removed and wall rebuilt.
I guess I had not read all the way through the Masonry Veneer Manufacturers Association guide yet. I appreciate the links to the details for building using the drain mats, weep screed, flashing etc. If I read your response right and the other recommend articles is that it does work as long as it is done right. MSV works. This all manages moisture from the outside, what about from the inside? As the sheathing will be cold and any moisture driven in through the inside will condense. Will the interior wall as described allow any moisture driven by high humidity to dry in the winter? In other projects I have done I kept the vapor barrier on the inside allowing the wall to dry to the outside.
Thanks for your support, Dave