Housewrap/Drainage Plane Behind Fiberfaced Polyiso or in Front?

cloves

Hi everyone,

I am about to begin residing my house. I was wondering what everyone's input was on where the housewrap should go in this case. I had a previous topic with some great feedback located here (Polyisocyanurate Rigid Foam Insulation Boards Over Plywood Sheathing & Vapor Barriers) Which touched on a few related questions.

House is located in North NJ (zone 5-6 border).

Materials:
-Framing is 2x4
-Fiberglass Batt Insulation R-13
-Polyiso 1.5" (fiberglass faced polyisocyanurate)(permeability <1.0) less than 1.0 according to the buildingscience article.

Design & Construction Option 1:
-Vinyl Siding
-Polyiso 1.5" (permeability <1.0)
-Housewrap (Tyvek or Dow)(Drainage Plane)
-1/2" Plywood
-2x4 Studs (Fiberglass Batt Insulation R13)

Design & Construction Option 2:
-Vinyl Siding
-Housewrap (Tyvek or Dow)(Drainage Plane)
-Polyiso 1.5" (permeability <1.0)
-1/2" Plywood
-2x4 Studs (Fiberglass Batt Insulation R13)

I am still a bit unsure of where the housewrap/drainage plane should be in my particular situation. Thoughts/comments?

kwikfishron

I prefer option 2 but instead of Tyvek (or the like) I’d use #30 felt.

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cloves

Thanks for the reply kwikfishron,

I think #30 felt would def present breathability issues. My house is currently wrapped with #15, and in certain spots where I have pulled off the wood shingles, so I could reflash windows, I have seen spots where the water has hard time drying out after rainfalls.

cloves

Bump

Gary in WA

Read this and click on the yellow colored links: http://www.greenbuildingadvisor.com/...s-housewrap-go

Follow advice here on windows and doors: http://docs.google.com/viewer?a=v&q=...WrZBbBZoIUXgxw

And most of this: http://www.mtcc1170.com/images/BCRainScreen.pdf

Two layers even with vinyl: http://www.fortifiber.com/pdf/News_I...o%20Layers.pdf

http://www.energy.wsu.edu/ftp-ep/pub...importance.pdf

Fasteners leaks: http://www.google.com/url?sa=t&sourc...kv-Xgg&cad=rja

Other thoughts: http://docs.google.com/viewer?a=v&q=...4EyM707m0gPdXQ

Flash windows on foam: http://apps1.eere.energy.gov/buildin...rica/37583.pdf

The felt paper is better than housewrap under cedar that leaks tannins. Only better install would have been a rain-screen under the shingles: http://www.coastalcontractor.net/article/135.html

You are using plywood sheathing, not Zip system or OSB......

Tyvek, not Typar........

More on the polyiso, next time....

Gary

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cloves

GBR thanks I will read up all the links you posted and post back! Thanks!