vapor barrier question

If vinyl siding is being installed over stucco, and there is a foam backer board being installed over the stucco, should there be a vapor barrier installed over the foam before the vinyl siding is put on? please help

Bill-where are you located

if you know anything about stucco (portland cement plaster assemblies) 2 layers of wrb are required on framed walls
block, eifs, defs often have different criteria depending on ahj
if the wrb can be verified w/mirror @ foundation termination or cover plate/fixture removal no need for more wrb

the bigger concern is how they plan on adhering the foam & vinyl onto the stucco
that will be their biggest challenge & sounds like a design i’d question from the get-go without prescriptive documentation

Bill-where are you located

if you know anything about stucco (portland cement plaster assemblies) 2 layers of wrb are required on framed walls
block, eifs, defs often have different criteria depending on ahj
if the wrb can be verified w/mirror @ foundation termination or cover plate/fixture removal no need for more wrb

the bigger concern is how they plan on adhering the foam & vinyl onto the stucco
that will be their biggest challenge & sounds like a design i’d question from the get-go without prescriptive documentation

you or client can call me for further

Personally, I think application of a vapor barrier over the foam would be appropriate. I could see the foam being subject to becoming waterlogged if not protected. I’m not so sure putting vinyl siding over stucco is a good idea.

There are a lot of unknowns here:
Is it real stucco or EIFS?
How is the backer attached?
How is the siding attached?
What are the manufacturer’s recommendations (both foam and siding)?
What is required under local codes in your area?

FYI
If it is EIFS, you might want to think twice in covering it up.
Here is renovation of an old Friendly’s Restaurant being stripped. Someone bought the building for something else.
Substrate don’t look to good does it.

Here is the picture;

mmm…black mulch…

I’m trying to remember what our buddy from OZ call that exactly and I’ll be damn if I can remember. :wink:

“Got it” Vertical Mulch. LOL

that was it partner…vertical mulch…in this case black vertical mulch…

:):slight_smile: