Caneil
Member
I agree, it is possible to densepack cellulose effectively in a wall without a dedicated vapor barrier. Sheetrock, taped, mudded with 2 coats of paint is regarded as an effective air barrier and these days the thinking is that one air barrier is good, one each side is best. And if you packed it in there's little air circulation/infiltration. But it doesn't take much. One spot missed, an upper stud cavity corner not quite dense enough with resultant settling, an air leak around an outlet, etc, etc. So the moisture then needs a way to get out, which it can do through an air barrier. And a metal or concrete exterior is trouble.
You write "basically". Does that means there are exceptions?
So far as experience goes, if you're addressing me, I grew up in a weatherizer/solar/cellulose installing and manufacturing/heat pump/spray foam family. Carried, or rather dragged my first bag of cellulose at age 10. Have densepacked the walls in somewhere beteen 100 and 200 buildings, insulated somewhere around a 1000 ceilings. And we built rigs to do ceilings solo, as in one guy blows the box truck full at the plant and goes out and does ceilings by himself. I'm 73 now, try really hard not to crawl around in attics, and have kept up with current practice in the weatherization field. The family company has been sold, but still exists as Hochstedler Energy Services.
No experience with Lowe's machines, but my experience with HD machines is that they lack the pressure required to get to 3.5lbs/cu ft. YMMV. For ceilings, they've worked well for me, but I inherited an ancient Incel blower (now Krendl) that's really slow, but achieves densepack levels. For what little cellulose work I do, it works pretty well.
You write "basically". Does that means there are exceptions?
So far as experience goes, if you're addressing me, I grew up in a weatherizer/solar/cellulose installing and manufacturing/heat pump/spray foam family. Carried, or rather dragged my first bag of cellulose at age 10. Have densepacked the walls in somewhere beteen 100 and 200 buildings, insulated somewhere around a 1000 ceilings. And we built rigs to do ceilings solo, as in one guy blows the box truck full at the plant and goes out and does ceilings by himself. I'm 73 now, try really hard not to crawl around in attics, and have kept up with current practice in the weatherization field. The family company has been sold, but still exists as Hochstedler Energy Services.
No experience with Lowe's machines, but my experience with HD machines is that they lack the pressure required to get to 3.5lbs/cu ft. YMMV. For ceilings, they've worked well for me, but I inherited an ancient Incel blower (now Krendl) that's really slow, but achieves densepack levels. For what little cellulose work I do, it works pretty well.