Peel-and-stick or Tyvek WRB?
Here is my proposed exterior wall assembly:
5/8 Drywall
Vapour barrier (for the building inspector)
2×4 studs at 12″ o.c with 3.5″ Rockwool batting
5/8″ Densglass Drywall sheathing
WRB <—– PLEASE NOTE THIS ONE 2″ Rockwool boards cement board open cladding I was commenting on other threads but thought I’d start a new one. I need the advice of the GBA members. Question: Considering cost, performance and application, Should I use a SA membrane or Tape the seams of the sheathing and Staple on a WRB? Self adhering membranes I’ve looked at: Vaproshield $1.2/sqft (no primer needed) Blueskin VP100 $1/sqft Delta Vent SA $1/sqft non-adhering membranes: Tyvek $0.13/sqft Tyvek Tape $0.12/linear ft So you can see we’re talking about a around a 9x of cost for the Self Adhered models. Yes the SA membranes are supposed to ‘save’ on labour philosophically, but there are differences, like size of the sheets and experience of the workers that come into play. Taping seams and stapling 9′ high sheets is quite simple vs vertically applied 5′ sheets of SA, cutting, rolling, getting all the seams right, etc. Does anyone have any experience with both and have any comments? Jamie
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Replies
Jamie,
Taping the seams of the Densglass and installing ordinary housewrap will be cheaper than installing a peel-and-stick product.
To achieve your airtightness goal, what matters is attention to details, not the use of peel-and-stick.
However, my question is, why the 2x4 at 12" o.c.? 2x6 at 24" o.c. uses less board feet lumber, allows for more insulation and your wall assembly has better R-value.
Armano,
The structural engineer spec'd it. The walls are 10' high and there are some good cantilevers going from on the 3rd floor.
Jamie,
I may have mentioned this on another thread where you were posting. You could consider using DensElement in place of DensGlass. It has an integrated WRB and air barrier. You can use a liquid applied sealant at the edges and opening and create a pretty tight envelope.
Hey Steve,
Thanks for the reminder. I sont think I'll.be able to get it for such a small order. But I'll look into it.
Martin,
As always, thank you for your advice.
Jamie