Zip panels as a WRB for SIPs?
We are building our home with 8.25″ SIPs made from OSB and EPS foam. I have been considering using a fluid applied WRB like one from Prosoco, Stoguard, Tremco, or the fluid applied Tyvek brand. I’m reading varying reports of their durability and have been turned off by their steep prices. For instance, based on estimated coverage, the Prosoco Cat 5 would run me around $1.44 per sq ft. Surprisingly, sheathing over the Sips with Zip system panels would be around $0.62 per sq ft. I know there will be differences in labor costs, but would using the zip system and tape actually be the better solution here?
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Replies
Brian,
I see no technical reason why you couldn't install Zip sheathing on the exterior side of SIPs. If you go this route:
(1) Stagger the seams (so that the Zip sheathing covers the SIP seams).
(2) Talk to the SIPs manufacturer or an engineer about a fastening schedule, to be sure that you have enough nails or screws.
(3) Remember to include a ventilated rainscreen gap between the back of your siding and the Zip sheathing.