Loose fill insulation - types

[matt_i]

Looking at "cellulose" but I don't know much about it other than the big boxes all seem to carry the stuff + blower rental.

Other than R-value are there any other things to shop for? Is there a better material which accomplishes the same thing? I'm OK with an incremental increase for something better, if I won the lotto I'd probably put in 100% Roxul....

(If it matters I am planning to fill the 9-1/4" deep spaces between trusses @ 24" oc in my shop's attic, above the drywall ceiling which I will be installing soon.)

Thanks for your insight.

 

[purplezr2]

Why such a narrow area, Does that even meet code for your area?

 

[strutaeng]

There's also loose fiberglass: http://www.homedepot.com/p/Owens-Co...ing-Blown-in-Insulation-System-L38A/100541755

I've used the cellulose before and it is very economical and works well. It does settle over time. The fiberglass is supposed to settle very little, but more expensive.

 

[matt_i]

Why such a narrow area, Does that even meet code for your area?

Not 100% sure here what you were asking about...the shop is 25' x 40', built with attic storage trusses which have a 2x10 bottom chord and are set @ 24" oc. All inspections have passed. So roughly 1000sf of space to insulate @ 9-1/4" deep.

 

[seanc_mt]

Did r60 of the green fiber in my 600 sq ft apartment on top of my shop. even with -30 outside and a small blaze king its tough to keep the place UNDER 75*.

Highly recommend as far as the settling argument the R value goes UP once it settles to its final depth.

 

[Walter_TA]

I went with fiberglass.

 

[Justind97]

You'll want a vapour barrier between it and the drywall. Soffit venting or a small knee wall made of 1/4" plywood to stop the insulation from getting blown into the soffits.

You'll be into it for roughly 45 bags. (Based on Weathershield, R32, 1000sq ft.)

 

[Radix2]

For maximum r value, you should pack the cellulose as best you can. Keeping the hose as you blow it down in the material will help, it will also keep the air from being as dusty.

One way to do it is to put up your ceiling and you floor (except for a strip at the middle). Then blow your cellulose in each bay as you insert and pull back the hose, you will get a nice pack and max r value, less dust and no settling.

Canada is big on plastic everywhere, but in MI you will basically never find it in a wall or ceiling. What will your ceiling be?

Fiberglass has been shown to be poor performing in cold climates, so I would not use it for blown in applications at all.

 

[matt_i]

Ceiling is going to be 5/8" drywall. I was planning to hand apply it, here is why. I already put the floor in the center part of the attic and a fair amount of stuff is up there now (problem with a dry roofed area, it gathers materials!!) so trying to blow it under the 12' wide center area from both sides doesn't seem like a recipe for good fill. Instead I was going to put up rows of drywall and dump it into the outside areas which are accessible from above. For the center, as soon as I put up the first 4' wide sheet I was going to try to pack insulation into half of it (2'), then place the next sheet of drywall on the next row, and then pack a 4' width into each truss cavity. Repeat until I get to the opposite outside area that's open from the top. Sounds like a lot of work but I feel like I can get a better/denser fill that way.

I was not planning a vapor barrier as I don't generate any significant water vapor underneath it, and I want to use construction adhesive to help hold the ceiling to the bottom chords.

 

[Radix2]

Ceiling is going to be 5/8" drywall. I was planning to hand apply it, here is why. I already put the floor in the center part of the attic and a fair amount of stuff is up there now (problem with a dry roofed area, it gathers materials!!) so trying to blow it under the 12' wide center area from both sides doesn't seem like a recipe for good fill. Instead I was going to put up rows of drywall and dump it into the outside areas which are accessible from above. For the center, as soon as I put up the first 4' wide sheet I was going to try to pack insulation into half of it (2'), then place the next sheet of drywall on the next row, and then pack a 4' width into each truss cavity. Repeat until I get to the opposite outside area that's open from the top. Sounds like a lot of work but I feel like I can get a better/denser fill that way.

I was not planning a vapor barrier as I don't generate any significant water vapor underneath it, and I want to use construction adhesive to help hold the ceiling to the bottom chords.

My insulation guy had no problem filling under a 18' wide attic truss from the sides. I think you have a good plan though and you gotta go with what is comfortable to you.

Painted and taped drywall is impermeable enough and all that is used on new construction anyway.. for the reason you state.