I am a hands-on homeowner who is finishing up the design of our new house to be build in central NC and I am trying to sort out the “best” way to handle the WRB and air barrier.  I will be providing some support for the construction of this house in various areas so sweat equity is available but I don’t want to spend time or money on redundancy unless there is a chance of failure that the redundancy would help to address.

I plan to use fiber cement siding, traditional framing with fiber insulation and far as I can tell, I have 4-options for the drainable WRB / sheathing / air barrier:

• OSB + Benjamin Obdyke Hydrogap WRB (taped) + sealant / foam on the inside cavity of the OSB
  • Can I rely on just the interior wall cavity foam / sealant in the absence of OSB tape?
• OSB with primed and taped seams + Benjamin Obdyke Hydrogap WRB (taped) + sealant / foam on the inside cavity of the OSB
  • This seems like it would be labor intensive to prime and tape the seams and since that has to happen before the WRB goes on, it could leave the OSB exposed for too long but how long is too long to have bare OSB on a wall before it gets wrapped?
  • Is there still value in sealing the interior OSB cavity with taped OSB seams?
• OSB + a peel and stick WRB like Benjamin Obdyke Hydrogap SA + sealant / foam on the inside cavity of the OSB
  • This seems like it could be efficient as the tape and WRB are combined into one step but its success seems highly dependent on 100% adhesion so that it doesn’t peel or delam which in an extreme case could introduce bulk water between it and the OSB
    • Is this a valid concern?
• Zip Sheathing (taped) + Benjamin Obdyke Hydrogap WRB (taped) + sealant / foam on the inside cavity of the OSB
  • This would likely install faster than my first two options since no primer is needed to tape zip sheathing
  • would the lack of primer and its associated material and labor costs offset the higher cost of this material?