Tape Sheating Seams or Detail WRB as Air Barrier
Hi GBA Community,
New build in Zone 5 and I’m trying to figure out my Air Barrier situation and needed some advice.
To set some context, standard timber construction – Exterior 2x6s – Single Bottom Plate and Double Top Plates – 1/2″ Plywood Sheathing – Plan is for a Brick Skirt and Vinyl siding
First Question: If I go with Siga Fentrium & Wigluv for the foundation and sheathing connection and the seams respectfully, is going with the Majvest 200 on top of that overkill?
Another factor is that my project will be sitting over the winter with no siding so I’m nervous about the UV exposure. The Siga rep has said that as long as I don’t go over 9 months I should be okay (the Majvest 200 product data sheet says 3 months). My other option is Tyvek CommercialWrap as that is rated for 9 months exposure.
(Majvest is $0.24 a sq/ft and CommericalWrap $0.27 sq/ft)
Should I skip the taping on the seams to save time and try to detail with WRB to serve as my air barrier? I’d be doing the work myself so I need something that is easier and most effective.
Should I chance the Siga Majvest over the Winter? Or, go with the Tyvek?
Any advice would be greatly appreciated.
Thanks,
Jason
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Replies
> Should I skip the taping on the seams to save time and try to detail with WRB to serve as my air barrier? I’d be doing the work myself so I need something that is easier and most effective.
I wouldn't try to detail a traditional WRB as an air barrier. One wrong move and your efforts to make it an air barrier are now causing it to trap water against your sheathing.
You can tape your sheathing seams as mentioned and then just detail the WRB as a WRB. Or, you could investigate self adhered WRBs which will solve both problems. If I were doing the work myself, I would probably opt for a self adhered WRB.