Helpful? 0

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 Thu, 02/03/2011 - 16:14
Edited Thu, 02/03/2011 - 16:38

Tags:

2 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

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 Thu, 02/03/2011 - 16:36

2.
Helpful? 0

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, GBA Advisor
Posted Thu, 02/03/2011 - 16:37

Other Questions in Plans Review

A very low addition...

In Energy efficiency and durability | Asked by ron letourneau | Oct 29, 14

Closed crawlspace with dehumidifier and foundation insulation

In Energy efficiency and durability | Asked by Michael Geoghegan | Oct 27, 14

Radon mitigation or ERV for old home with dirt wall basement

In General questions | Asked by Scott Van Der Veer | Oct 30, 14

Drywall directly on stem wall

In General questions | Asked by Tom Frisch | Oct 30, 14

Foam Insulation Question For 100 Year Old Brick Home

In Green building techniques | Asked by Wes Leland | Oct 30, 14
Register for a free account and join the conversation


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