Damaged Sheathing - Use Insulating Foam Sealant Before Fiberglass Bats? - Remodeling - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Remodeling

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools
Display Modes
Old 07-22-2019, 06:12 PM   #1
Member
 
Join Date: May 2018
Location: Long Island NY
Posts: 92
Rewards Points: 180
Default

Damaged sheathing - use insulating foam sealant before fiberglass bats?


Remodeling a room with two exterior walls (corner room, ground floor, on concrete), and had to repair some of the framing (moisture, termites). Bottom plates replaced and all the damaged studs were sistered with new studs. I want to seal things up before installing fiberglass bats.

Some of the sheathing is damaged (this is exterior gypsum, which apparently was popular in the 60's). These are the worst spots:





There is a brick veneer outside this sheathing, so taking down the brick and replacing the sheathing is not practical.

Should I just fill this in with insulating foam sealant, such as Great Stuff Big Gap Filler?

As far as blocking air intrusion in tiny gaps, should I use insulating foam sealant such as Great Stuff Gaps and Cracks where the sheathing meets the bottom plates?


Or how about where the bottom plates meet the concrete (a termite shield was laid down between bottom plate and concrete)?


Lastly, up top, there are gaps between the sheathing and framing. This was never insulated with fiberglass.


Here's a closeup:


Should I leave it alone, or should I place some fiberglass insulation in that top gap? Maybe the bottom gap could get Big Gap insulating foam?
jbrah is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-22-2019, 06:19 PM   #2
Member
 
Join Date: May 2018
Location: Long Island NY
Posts: 92
Rewards Points: 180
Default

Re: Damaged sheathing - use insulating foam sealant before fiberglass bats?


After dealing with blocking air intrusion, the next issue is laying down fiberglass bats. Because many of the studs were sistered, the stud bays are no longer 14-1/2" wide. Most are now 13" wide, and a couple are 11-1/2" wide (stud bays next to window where both sides of the bay were sistered).

I'll have to cut down the bats for the 11-1/2" bays. Is it worth the effort to trim the bats down for the 13" bays?

Given all the new studs and potential for thermal bridging, I'll put up foam board and then drywall on top of that, so that the foam breaks the thermal bridge.
jbrah is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-22-2019, 07:09 PM   #3
Property Mgt/Maint
 
Join Date: Mar 2015
Location: Upstate NY
Posts: 5,561
Rewards Points: 6,368
Default

Re: Damaged sheathing - use insulating foam sealant before fiberglass bats?


You are on the right track. Spray foam what you can. Let set for a day and trim anything needed.
Regarding cutting down fiberglass. Yes you should. What I do is remove the paper, cut the fiber glass to fit, then staple the full sheet of paper back over the studs.
__________________
[political signature removed]
Yodaman is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 07-24-2019, 01:29 PM   #4
Member
 
Join Date: Jan 2019
Posts: 244
Rewards Points: 484
Default

Re: Damaged sheathing - use insulating foam sealant before fiberglass bats?


I would use a two-part foam such as this:
https://www.homedepot.com/p/Touch-n-...2200/204962748
It will effectively provide an air seal but equally important it will double the R value of the bay. Glass bats when installed have been tested and shown to provide half their rated R value in real world installations. Even an inch of spray foam will add 3 points to the R value for the wall insulation.

It works well for irregular spaces and I used it with a bathroom remodel where I put in blocking for future attachment of hand rails and so did not have a continuous bay the length of the studs.
Calson is offline   Reply With Quote
Old 07-24-2019, 05:43 PM   #5
Property Mgt/Maint
 
Join Date: Mar 2015
Location: Upstate NY
Posts: 5,561
Rewards Points: 6,368
Default

Re: Damaged sheathing - use insulating foam sealant before fiberglass bats?


Quote:
Originally Posted by Calson View Post
I would use a two-part foam such as this:
https://www.homedepot.com/p/Touch-n-...2200/204962748
It will effectively provide an air seal but equally important it will double the R value of the bay. Glass bats when installed have been tested and shown to provide half their rated R value in real world installations. Even an inch of spray foam will add 3 points to the R value for the wall insulation.

It works well for irregular spaces and I used it with a bathroom remodel where I put in blocking for future attachment of hand rails and so did not have a continuous bay the length of the studs.



I have never really heard good things about these DIY foam spray kits. Reading the reviews there are plenty of folks that gave it a 5 star, but I always read the bad ones first. And plenty folks have consistency issues, rated coverage issues, nozzles clogging etc. It just seams a little pricey with a good possibility of problems for my taste. Sounds like you had success.
__________________
[political signature removed]
Yodaman is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts