Insulating 2×4 exterior walls
Bobbbby
| Posted in Energy Efficiency and Durability on
I am remodeling my rental home with 2×4 exterior walls located in CZ 6. The home is being stripped down to the studs and to the sheathing which is 3/4 tongue and groove planks. I am attempting to formulate a wall assembly that will result in the best bang for the buck in terms of comfort and efficiency. After reviewing the information on this site the best plan I could come up with is:
Vertical vinyl siding
horizontal pressure treated strapping
Tyvek
2” reclaimed eps or poly iso (whatever I am able to get my hands on)
3/4 tongue and groove plank sheathing
r13 fiberglass
Sheetrock
Any input would be appreciated.
Thank you!
Bob
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Replies
That sounds pretty good to me. I would probably go for metal or wood siding as opposed to the vinyl but, to each his own. I would probably go for mineral wool batts instead of fiberglass for a slightly better performance at R-15, an easier installation, and added fire resistance. Good luck. Sounds like you're on the right path.
Thank you for the quick response! Am I correct in assuming the Kraft face on the fiberglass batts will satisfy the vapor retardant requirements for the interior?
Yep, that kraft facer is basically an old-school smart vapor retarder and will work just fine here.
Note that it's a good idea to detail your interior drywall airtight regardless. You'll get a much better performing wall assembly that way.
Bill
r 15 fiberglass for 2x4 walls is widely available. where i live its about 30-40 cents cheaper per sqft, too.
I would strongly consider a peel-and-stick WRB to go on the outside of your board sheathing. All of the seams there would be very difficult to air seal with any other WRB, especially mechanically-fastened house wrap. And notice I am saying to install this on the sheathing, under the exterior insulation.
Considering cost I’m wondering is a peel and stick on the sheathing going to do much for me when I have poly iso on top of it and then tyvek on top of the poly iso in case seams spread apart?
Is it worth the redundancy?