0 Helpful?

Window flashing with exterior rigid insulation

I operate in climate zone 5B which has about 6,600 HDD. Homes built here generally do not require cooling systems -- only heating. My question has to do with where the water resistive barrier should be placed on the construction detailed below:

Form the inside out:
1. 1/2" sheetrock
2. 2x6 framing filled with dense-packed cellulose insulation
3. 7/16" OSB sheathing
4. 2" XPS rigid insualation
5. Jumbo Tex-type WRB -- bassically 2 layers of 15# impregnated roofing felt
6. Stucco wire
7. 3-coat stucco system

My thinking is that the flashing, particularly the bottom window flashing, should extend from the window nailing fins over the 2" XPS rigid insulation and then down between the two layers of Jumbo Tex WRB. My thinking is that the 1st layer of the Jumbo Tex bonds to the back of the stucco system so any moisture should be allowed to run down between the 2 layers of Jumbo Tex.

Is that right?

Asked by Steve Vollstedt
Posted Feb 3, 2011 4:14 PM ET
Edited Feb 3, 2011 4:38 PM ET

Tags:

2 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.

Hi Steve,
Why wouldn't you extend flashing out beyond the stucco? There may be a good reason.. but I can't come up with one.
Cheers.

Answered by Chris Koehn
Posted Feb 3, 2011 4:36 PM ET

2.

Steve,
You can install your windows as "innie" windows or "outie" windows. (If you are unfamiliar with those terms, see ‘Innie’ Windows or ‘Outie’ Windows?)

If you want to install your WRB on the outside of the rigid foam, I suggest that you install your windows as outies.

Answered by Martin Holladay
Posted Feb 3, 2011 4:37 PM ET

Other Questions in Plans Review

Closed cell spray foam/cellulose combination

In Green building techniques | Asked by Steve Lenertz | Oct 21, 17

Polyiso and loose-filled cellulose insulation in cathedral ceiling

In Energy efficiency and durability | Asked by LRSeries | Oct 19, 17

Forced hot air control question

In General questions | Asked by Lostedge | Oct 23, 17

AgePan with WRB

In Green products and materials | Asked by Steve Babcock | Oct 23, 17

Vaulted ceiling, open attic

In Green building techniques | Asked by pshyvers | Oct 21, 17
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!