Shop to Living Space - No Wrap OSB siding


  #1  
Old 11-17-21, 05:21 PM
B
Member
Thread Starter
Join Date: Sep 2021
Posts: 13
Received 0 Votes on 0 Posts
Shop to Living Space - No Wrap OSB siding

I am making a living space in part of a shop. The shop had No Wrap just OSB siding on 2x4 studs. We thickened the 2x4 external wall by adding a second 2x4 wall for running our plumbing + electric. We are ready to start insulation. We now have a whole 2x4 wall dedicated to insulation and we have both pink bats and pink foam board. We also have both GE Advanced Silicone and GE All Purpose Silicone. The bldg (shop) was never wrapped it is just osb siding on studs. part of the shop we are making into an ADU. This is why we bought the silicone.

Considering first sealing up each interior perimeter of each stud bay and any seams we come across with silicone. Then putting in a layer of bat and then a layer of foamular.

Would that be a good method considering it was not wrapped?
also, would it be advised to put a layer of plastic or house wrap up? Where? against the osb? Or enclosing all the insulation?

Honestly, the more articles I read about vapor, air and moisture the more confused I get...it is kind of a black hole of info.


 
  #2  
Old 11-17-21, 05:58 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,282
Received 1,534 Votes on 1,378 Posts
Adding your location to such a question would be a good idea.

A WRB is required on the exterior under any kind of siding, its sole purpose is to protect the sheathing in the event of a leak, such as by wind driven rain. If you don't have a wrb, you better hope your siding never leaks.

The silicone is kind of pointless. If you are planing on putting foam in against the exterior sheathing, simply use spray foam or a foam adhesive to air seal the perimeter of the foam. The more foam the better. (2" is best) Your batts (no vb) would go on the interior. Or if you prefer to use Kraft faced insulation, that would not be the end of the world, but I would not use poly.
 
  #3  
Old 11-17-21, 06:53 PM
B
Member
Thread Starter
Join Date: Sep 2021
Posts: 13
Received 0 Votes on 0 Posts
I am in Kalispell MT. Are you saying a good approach might be to put in the 2" foamboard > seal it > then put in bats? So the foam board is placed against the exterior sheathing and the bats are towards the inside?
 
  #4  
Old 11-17-21, 07:27 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,282
Received 1,534 Votes on 1,378 Posts
Yep. That's best for cold and moderate climates. When you put up drywall, air seal the top and bottom edges of the sheets and any exterior corners with green glue or similar as an air barrier. Be sure you caulk the bottom plates to the floor. Before you rock the ceiling, install baffles in the rafters above the top plates, block with foam above the top plate to the chute, spray foam in place.
 
  #5  
Old 11-18-21, 04:43 PM
B
Member
Thread Starter
Join Date: Sep 2021
Posts: 13
Received 0 Votes on 0 Posts
OK I think I understand on the walls. Regarding "Before you rock the ceiling, install baffles in the rafters above the top plates" Would it be the same thing or similar to do what the did here? (Link removed)
My point is you are covering the rafters and leaving an air gap underneath. Also, These images show I dont have soffit venting and I dont think I have ridge venting either...so not sure how that changes what I would do or not do to the area above the rocked in lower part.


 

Last edited by bobmane; 11-18-21 at 05:08 PM. Reason: images
  #6  
Old 11-18-21, 04:51 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,282
Received 1,534 Votes on 1,378 Posts
  #7  
Old 11-19-21, 07:56 PM
B
Member
Thread Starter
Join Date: Sep 2021
Posts: 13
Received 0 Votes on 0 Posts
Oh OK I dont want to blow foam I want a storage area above the ceiling...any other options
 
  #8  
Old 11-19-21, 08:05 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 29,282
Received 1,534 Votes on 1,378 Posts
You do realize that in your climate an attic should have R49-R60 of insulation above the ceiling, right? If you want storage up there you would need to have the underside of the roof professionally spray foamed and I don't think you realize what that will cost.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: