Possible to dense pack cellulose by hand?
Zone 3a/4a right on the line….
I am renovating an 1870’s balloon framed farmhouse. I am residing the house and thus opening it up from the exterior. Doing this one wall section at a time. While I have the walls open I am insulating from the outside. I hate fiberglass. I’ve already successfully dense packed a number of the wall cavities with the following method….
1. rip plywood in 2×8 sheets and fasten longways to wall.
2. hand pour/pack cellulose in cavities
3. tamp with 2×4 until tightly packed/cant pack anymore
4. I’m calculating the cubic footage of the wall cavities as I go and comparing to # of bales of insulation ive used and I’m averaging aroud 4 lbs per cubic foot
What is wrong with doing it this way other than it being time consuming?
Am I missing something?
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>"2. hand pour/pack cellulose in cavities
3. tamp with 2×4 until tightly packed/cant pack anymore
4. I’m calculating the cubic footage of the wall cavities as I go and comparing to # of bales of insulation ive used and I’m averaging aroud 4 lbs per cubic foot"
4lbs is a density beyond where it's R/inch will be going down, not up, and won't be as consistent, but it's way better than nothing. The sweet spot for cellulose performance is an even-density( not lumpy) 2.8-3.2.bs, though in colder climates 3.5lbs may be necessary to prevent settling in 2x6 wall cavities. In zone 3A something like 3-3.2lbs would be enough.
It's possible to dense pack to 2.8lbs+ with a single stage rental blower if there is enough room to fish the hose all the way up or down into the cavity, though it's easier using narrower 1-1.25" I.D. dense packing tubes. With a balloon frame you'd have to install air barriers on the open cavity tops (and bottoms, if open). Corrugated cardboard stapled to the framing with a X cut into it for inserting the dense packing tube can work pretty well when dense-packing to less than 3.5lbs.
Don't rule out "2- hole method" lower density cellulose, which usually ends up around 2-2.5 lbs. If lower density cellulose settles over a decade or so it can be topped off. On a full-gut rehab project I've seen 2-hole method cellulose that hadn't sagged a bit in a 2.5 story balloon frame 30 years after installation. It looked like it could have been installed 30 hours (rather than years) prior.
Thanks for the answer Dana. Wondering why you said cellulose needs a higher density to prevent settling in cold climates. It is more prone to settle in clod climates?
I hand installed cellulose in rafter bays from the top. - I put the cellulose in a large box, then used a drywall compound mixer on a drill to fluff the insulation prior to installation. I got very close to the volume listed on the bag.
I've thought about doing this same thing myself. Have your done any thermal imaging or other testing to check the results over time?
I dense packed 2 walls of a 10x10 addition with a HD Blower that comes free with the cellulose purchase.
I retrofitted a 1 1/2 tube to the end of the hose and retrofitted a baffle into the hopper of the Blower machine so it could only send 1/3rd as much cellulose through the hose as it would have. This gave it a higher blow to cellulose ratio.
This method took a very long time do to the restriction of cellulose being blown (Not to mention the many times the machine jammed because of the baffle) It took me about 8 hours to dense pack 20 feet of 8ft tall 2x6 wall.
The installation access points where a hole cut in the sheathing mid way up the wall at each stud cavity.
I'm 2 to 3 years out (hopefully) from a design build and would like to try the hand packed dense pack method on a double stud wall system. Any thoughts on how you would approach that given your experience with your retrofit?