Insulating behind drywall & stucco

[ps2cho]

Installing a mini split in the attached garage. The ceiling in the garage has fiberglass insulation, great. But when I cut into the walls, unfortunately I found none.
One wall gets sun all day long so I feel that side in particular is a non-negotiable or it will just radiate heat through.

Whats the best options to get insulation behind the drywall? Have a 3" gap between the drywall and Stucco exterior.

Can I cut rectangles from stud to stud all the length of the garage, then feed insulation up and down the wall possibly?

Thoughts or whats the most painless way to get some insulation in there?

 

[larry4406]

Insulation companies can blow into cavities; upper hole and bottom hole each bay so drywall repairs.

Do you have adequate power in that wall? If not tear off drywall, wire, air seal, insulate, and rehang rock. That’s what I’ve been doing.

 

[finn]

Blow in cellulose. I have seen Dense pac , possibly blown in wet(?). It doesn’t settle that way, I presume. Don’t know how it dries though.

 

[larry4406]

Blow in cellulose. I have see. Dense pac , possibly blown in wet(?). It doesn’t settle that way, I presume. Don’t know how it dries though.

Unknown blocking in a wall kind of kills this….

 

[Firebrick43]

Blow in cellulose. I have see. Dense pac , possibly blown in wet(?). It doesn’t settle that way, I presume. Don’t know how it dries though.

Dense pack need the wall open and use with netting. The cellulose is accelerated and the air (via the netting) has to exit at that point. If the air rebounds the cellulose rebounds as well and settles on gravity and weight above it.

 

[finn]

Dense pack need the wall open and use with netting. The cellulose is accelerated and the air (via the netting) has to exit at that point. If the air rebounds the cellulose rebounds as well and settles on gravity and weight above it.

The stuff I saw was in my son’s first house when it was being built,, maybe a little over twenty years ago. I had never before seen whatever it was, but it looked like spray foam from afar, and built up / sealed like foam, but it was a cellulose product. Ir sealed well, whatever it was.

Oh, well. I suppose spray foam, albeit expensive, would work.

 

[Firebrick43]

The stuff I saw was in my son’s first house when it was being built,, maybe a little over twenty years ago. I had never before seen whatever it was, but it looked like spray foam from afar, and built up / sealed like foam, but it was a cellulose product. Ir sealed well, whatever it was.

Oh, well. I suppose spray foam, albeit expensive, would work.

Was it applied to the open stud bays? Wet sprayed cellulose is a thing and it’s a pretty good product. Better performing than fiberglass and it doesn’t settle either.

It’s Sprayed on with air pressure and a sprayer nozzle sprays water/mild adhesive mix at the same place/time. It’s then screeded off with the face of the studs and the product that is removed is vacuumed back to the blower and reused.

I am not sure wet sprayed can be applied either to a closed wall? I have never applied it, just regular cellulose in attic and dense pack in two small buildings walls in this manner.

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[finn]

Was it applied to the open stud bays? Wet sprayed cellulose is a thing and it’s a pretty good product. Better performing than fiberglass and it doesn’t settle either.

It’s Sprayed on with air pressure and a sprayer nozzle sprays water/mild adhesive mix at the same place/time. It’s then screeded off with the face of the studs and the product that is removed is vacuumed back to the blower and reused.

I am not sure wet sprayed can be applied either to a closed wall? I have never applied it, just regular cellulose in attic and dense pack in two small buildings walls in this manner.

Mooney Wall -- A low cost, high R value wall

The Mooney Wall provides a high R value wall with much reduced thermal bridging -- all for a low cost. Good for retrofit or new construction

www.builditsolar.com

I was at the site when the house was being built, so I suspect that’s when I saw it, ie before the Sheetrock was hung. I do recall discussing the wet spray with my son at the time.

It was when my granddaughter was about to enter the world, and she’s away at college now, so the details are fuzzy. Must have made an impression though, if I still recall some of it.

 

[pcmeiners]

Unknown blocking in a wall kind of kills this….

Applied cellulose to multiple homes, mostly older homes with balloon framing.

Wet application is out with enclosed cavities.
You need to blow in dry insulation, top and bottom holes in every stud, blow in until machine bogs down. As to chocks you will need to find them, generally you can tell if a chock is in a cavity, as the fill time is short with a chock forming a cavity, stud finder could be useful. Blown in cellulose does settle a little if you fill until machine bogs down. If you do not fill until then the machine bogs down, loosely filled cavities will settle a lot. Use a 3" or large hole saw for the fill holes, no smaller, KEEP the cut out circles for repair. For the repair push the circle in the holes, slightly deeper than the wall board, joint compound over them, first shot of compound just enough to "glue" the circles to the wall board, let dry thoroughly, sand, re-compound.

 

[readhead]

Remove the drywall, add or change things in the wall and put up something new on the wall. Not as difficult as you might think.