Or should I just use a regular OSB? We've got a 2x6 frame that's going up in a few days, and we're in Zone 3, central Oklahoma. I still don't know what insulation I'm using on the inside. Thanks so much to anyone who can help!

You can tape foam to be an air infiltration barrier. But I think a more interesting question is "does it pay to have multiple air barriers"?

Does it? I'm totally clueless on that! I just know that I want to have a really good air barrier! We may also have some spray foam on the inside.

Does the foam board work as a moisture barrier, or do I still need the Tyvek/Zip?

Thanks so much to anyone who can help! I'm trying to order the sheathing today.

Building Science recommends an air barrier at the sheathing plane, either ZIP sheathing, taped, or Tyvek, taped.

Would OSB (taped or glued), plus foam board (taped) be an air barrier at the sheathing plane? I'm not trying to skimp, I just don't want to do something that's unnecessary. It's going to cost around $800 extra, which is worth it if I need it, but would buy a few extra squirts of insulation if I don't. Thanks so much!

Gluing OSB will not help at the horizontal joints. Taping OSB will work but the OSB has to be primed so that the tape will stick long term. Is it absolutely necessary? I don't think anyone can say with certainty right now, but it's very hard to do later.

Thanks! I know I read that you can use zip board tape, is there other tape that would work as well?

You can use polyurethane caulk on the exterior OSB seams. You might also consider caulking the interior framing members to the OSB (everywhere framing member meets OSB), to provide an effective air infiltration barrier, if you are not going to flash foam the interior.

-Rosalinda