Does the housewrap go over or under the rigid Foam insulation siding?
This website is awesome and I have spent many hours browsing through articles. None of my builder friends, myself included, have ever used rigid foam panels under the siding of a home under retrofit. Consequently i have kept my eyes open for the answer to the above question but the solution has still alluded me. I am planning on replacing all of the siding and windows in a circa 1970’s home that I recently acquired and I thought that this will be an excellent opportunity to get my feet wet with applying rigid foam panels under the siding. After much study, and all things considered, I have decided to use two layers of 1-1/2″ EPS. As a greenhorn who has never employed this method before here is what I and thinking of using:
a. Before proceeding, the current siding is also the shear panel. So I will necessarily have to install a new layer of ~1/2″ OSB.
1. Over the top of the OSB will go 2 layers of 1-1/2″ EPS IF I can find a foil faced version. I was also considering Foil-Faced Polyiso but here in zone 5 with a nominal 15 days of 10 degree weather per winter I am concerned about the cold weather performance of Polyiso. Plus there is also the cost factor.
2. I will either tape all of the seams using a quality tape like Dow Weathermate or one of the Venture products. Any other recommendations would be greatly appreciated.
3. Alternatively, many of the articles I have read on this site recommend using one of the many canned spray foams to seal the seams. So, What is the current thinking: Tape, Foam, or a combination of the two.
4. On top of the rigid foam panels I will install 1×4 furring strips using long washer-head screws. They are kind of expensive but it seems to me that this isnt the place for plastic capped nails or screws.
5. Attached to the furring will be something on the order of SmartSide… I think that is a PPG or OC product.
The one big question still remains: if I use housewrap where does it go and is it even necessary?
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