Canned Spray Insulation Not Sticking Well - Insulation - DIY Chatroom Home Improvement Forum
Advertisement


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

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

Reply
 
Thread Tools Search this Thread
Display Modes
Old 12-08-2018, 01:58 AM   #1
Member
 
l008com's Avatar
 
Join Date: Mar 2015
Location: Woburn, MA
Posts: 343
Rewards Points: 684
Send a message via AIM to l008com
Question

Canned Spray Insulation Not Sticking Well


Room by room, I am tearing down the sheetrock on the external wall, removing all insulation and replacing with rock-wool. That part of the project is going well.

But where the internal walls meet the external walls, I have this cavity that's about 3.5" by 4". I've uncovered three so far but it's clear every joint will have them. They have no insulation in them at all. There isn't nearly enough access to squeeze in batted insulation. Plus there are 2x4's scattered around in there, that you would never be able to squeeze batting behind.

I'm attaching a floor-plan with the intersections circled incase it's not clear what I'm talking about. I'm also including a photo of one of the walls, where you can see theres just a sliver of access to each cavity right at the corners.

One thing I could do is peel back some sheetrock on the walls so I have easy access, then I would be able to jam some rock wool in there, but I want to avoid that.

So at the direction of a contractor friend, I got a few cans of 'Great Stuff' big hole filler. I've used their other foams before for various things and they worked well enough. But it didn't go well here.

As the title hinted at, the main problem is that this stuff just didn't stick. I wasn't trying to fill each bay. I mainly just wanted to spray a bunch of beads up and down. Then once they set/expand, spray more on top. Repeating over and over until they were filled. What happened was, it was like spraying whipped cream. Almost as soon as I sprayed it, it started to fall off and pile up at the bottom of the bay, inside the wall.

Is there anything I can do to make this stuff stick better? If it would stick, I think doing it this way would work. The heat was set at 64*when I did this. And it was about 30 out and falling. I could pretty throw a space heater on the bay. Getting the hot air to actually go in will be tricky but it should work. I've also read things about spraying water on the foam to cure it. Would that help with sticking? I could pre-spray the walls with a little water right before spraying?
Attached Thumbnails
Canned Spray Insulation Not Sticking Well-main-floorplan.jpg   Canned Spray Insulation Not Sticking Well-img_6827.jpg  
l008com is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-08-2018, 04:13 AM   #2
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 38,155
Rewards Points: 920
Default

Re: Canned Spray Insulation Not Sticking Well


Don't cut the drywall there is stud on the end and that is what is nailed to the blocks. The system is designed to hold the interior wall in place. There is about 4 or 5 ways to tie the walls together and the worst is when they use a full stud instead of those blocks and you have no access.
nail something up to block the cavity on one side of the wall. Drill holes every 6 or 8" in a strip of wood and tack it up over the slot.. Fill at the bottom hole let it foam up and move up to the next hole and so on.
Nealtw is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-08-2018, 06:41 AM   #3
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,751
Rewards Points: 304
Default

Re: Canned Spray Insulation Not Sticking Well


Since you have mentioned temperature and moisture you have probably read that winter is not a good time to be using can foam. As you noticed, can foam is not really a spray foam, it creates beads of foam, although I have never used the large gap cans.

Drill holes as mentioned and fill in layers from the bottom up. Not an expert on it but from reading both moisture and heat help. I've used moisture in small areas and it increased the expansion. Test before you go crazy but warm things up as best you can.

Bud
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-08-2018, 06:46 AM   #4
Member
 
l008com's Avatar
 
Join Date: Mar 2015
Location: Woburn, MA
Posts: 343
Rewards Points: 684
Send a message via AIM to l008com
Default

Re: Canned Spray Insulation Not Sticking Well


Quote:
Originally Posted by Bud9051 View Post
Since you have mentioned temperature and moisture you have probably read that winter is not a good time to be using can foam. As you noticed, can foam is not really a spray foam, it creates beads of foam, although I have never used the large gap cans.

Drill holes as mentioned and fill in layers from the bottom up. Not an expert on it but from reading both moisture and heat help. I've used moisture in small areas and it increased the expansion. Test before you go crazy but warm things up as best you can.

Bud
Actually the heat comment was based on the expensive 2-part stuff. I was specifically told the canned stuff doesn't have the same requirements. The fine print on the can said something like 60 to 90 i believe, which I was in. But it should be easy enough to warm it up more before my next foaming session.

I know Winter isn't the ideal time but I'd rather not go all winter without insulation. And I want to finish these walls so really I'd be going forever without insulation in these gaps because once the walls are finished, I'm not tearing them apart again.
l008com is offline   Reply With Quote
Old 12-08-2018, 07:07 AM   #5
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,751
Rewards Points: 304
Default

Re: Canned Spray Insulation Not Sticking Well


The space you are dealing with is frequently covered by sheathing before the insulation crew arrives and as you have learned they just ignore it. I do infrared inspections to locate cold areas and many are just like yours.

I have drilled access holes around windows where a tight fit would not allow the can nozzle to fit and have removed those windows in later years where I saw how it worked, it did. But I have tried filling larger spaces with limited results.

Do some drilling and filling to get a feel for how close you want those holes. The holes will also provide better access for spraying in a touch of moisture.
Here's a link discussing the benefits of a bit of moisture.

Bud
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is online now   Reply With Quote
Old 01-11-2019, 02:42 PM   #6
Member
 
l008com's Avatar
 
Join Date: Mar 2015
Location: Woburn, MA
Posts: 343
Rewards Points: 684
Send a message via AIM to l008com
Default

Re: Canned Spray Insulation Not Sticking Well


So I did what others said and blocked up the cracks where i have access, then drilled holes and emptied a whole can into that cavity. I didn't use wood though, I used strips of sheetrock! I have so much left over small pieces and I finally found a good use for them! I did 6 different holes. Since there was already some insulation in there from the first time, it should have given the new foam a lot more surface area to stick to. Tomorrow ill peel off the sheet rock and see how it came out. Hopefully well. Not sure it will work as well on a totally fresh bay though.
l008com is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Insulating an Attic - Spray Foam in the Rafters v. Cellulose on the Floor esteve999 Insulation 5 12-13-2014 10:29 AM
Cape Cod Style House Attic/Crawl Space Insulation Help Danielg Insulation 24 05-21-2012 08:20 AM
Home Energy Audit & Spray Foam Insulation sweets Insulation 7 09-08-2011 10:45 PM
Canned Foam Insulation WindingRoad Building & Construction 5 01-02-2011 09:08 AM
Rafter Vents and Insulation nofx1981 Roofing/Siding 15 03-10-2010 08:14 PM




Top of Page | View New Posts