Building scientist that I have talked to prefer one to two layers of roofing felt instead of synthetics such as Tyvek.  I have heard some of them say that the synthetics can compound the problem in wet humid areas.

Joe Lstiburek did a test I found in JLC's Moisture Control book in which he says StuccoWrap with a bond break of felt OVER the stucco wrap produced the best system for drainage.

Thanks for your input Alton, but...

I understand that these problems occur in wet, humid areas. That is not what my question was about, since the project is in a semi-arid, low humidity region...

So,... anybody out there with direct firsthand knowledge?

For real firsthand knowledge, get off your duff, go to nearest town, ask around until you determine the best EIFS installer in the area, then go ask him/her how they do it. That's the best way to get REAL FIRSTHAND KNOWLEDGE of how something is done in a specific geographical area.
This forum is made up of folks from all over the world, and I doubt that any of us have much experience outside of the areas in which we have lived and worked. And unless one of us happens to live in NW Wyoming, we will not have that direct knowledge you apparently are seeking.

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