[Greenbuilding] mesh for retaining open cavity blow-in insulation

[wmdorsett at sbcglobal.net]

Reuben, I remember a short basement wall where the drywaller had pressed 
in fiberglass insulation with half inch rock. The wall was very 
definitely scalloped by the outward pressure between the studs. One 
consideration is that there is a peak density at which you have minimal 
increases insulating value with more packing, with most cellulose 
blowers being able to pack it about as tightly as that optimum level. If 
you decide to pack it tighter you might put up 5/8" rock to keep it from 
scalloping. Half inch rock on ceilings tends to this problem anyway.

Bill Dorsett
Sunwrights
Manhattan, KS

Reuben Deumling wrote:
> On 8/27/07, jefro at mcn.org <jefro at mcn.org> wrote:
>   
>> We faced this same question last month.  We opted to simply install the
>> sheetrock and drill holes.
>>     
>
>
> I am warming to this idea, though will still use the fabric on the vertical
> walls. My concern is that with 7-1/2" x 22"+ bays I might have trouble
> getting the stuff packed in as tightly as I'd like to. Perhaps this is not a
> concern, but a post from Corwyn a while back got me thinking about this.
>
> So I was wondering whether it might make sense to add a baffle/compression
> step after sheetrocking the first half of the ceiling and drilling the
> requisite holes?  I'm imagining mounting a 7-1/2"x 22" board on the front of
> a 6' pole with which to compress the bay a few times--or to insert and back
> off gradually? I think this method could work until I put in the last 32"
> strip down the middle of the ceiling. This would leave 22" x 32" x 7-1/2"
> cavities I would have to rely on blower pressure to compress.
>
> Thoughts?
>
> Reuben Deumling
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