I want to do some wall insulating in the near future and it occurs to me that my knowledge of blowing in cellulose is a little light. Are the machines that are “free rentals” at the big box stores up to the task of dense pack (>3.0 lbs) in walls? I was under the impression that they were only for blowing loose fill.
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Replies
Bueller?
I'll give you a bump. Not my area of expertise but I've done it a
couple of times.
The freebies will work. Slow and can clog up from
time to time, but they get the job done.
I've dense-packed with the big box machines, but would suggest you get a couple of items in addition to what they give you. Talk to these guys;
http://www.regalind.com/index.htm
They can sell you a 2" to 1" tapered nozzle and also a 4' aluminum nozzle that's easier to get into the far areas of stud bays if you're using mesh.
Edit: another thing that's really handy is a remote switch for the person doing the blowing. The dang things are loud, and the hopper feeder can't hear. On the blowing end, you'll recognize clogs right away, and if you can shut the machine off imediately it keeps the clog from backing up in the hose and generally makes a thankless job a little less crappy.
http://www.amazon.com/gp/product/B00004S9AI/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B00004S9AL&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=188V3FCAZ3DZHHXY6A0T
Everything will be okay in the end. If it's not okay, it's not the end.
Edited 9/11/2009 10:34 am ET by PeterJ
Have you successfully used that 2" to 1" reducer? I tried it a couple times but it would clog almost right away.
I did use it to fill some 2x2 stud bays and some voids after the 4' wand. Fine tuning the flow was key and getting the machine quickly shut down when it plugged.
I got to where I had an empty garbage can close by and when I could hear it start to plug, I'd pull the nozzle off and dump into garbage can while shutting machine down. That's where the remote was appreciated the most.
Don't have to tell you, I imagine, but the learning curve is a messy one!
Everything will be okay in the end. If it's not okay, it's not the end.
My son and I just did a dense pack Mooney wall last week with the big box blower. I calculated the number of bags and in the end we came up with a few extra bags so I think we were a little light on the dense pack. We did go back and hand fill some areas that were thin and found one bay we missed totally. The mesh generally had a nice bluge to it, just right. No noticable setteling at the top after a week.
I built a nozzle out of a 1-1/2 PVC long sweep elbow that I cut to about 60 deg sweep. A few fittings and some duct tape and it worked like a charm.
Took about 2 hours for 110 feet of walls.
I recently did some dense pack cellulose behind insulmesh. I used regal insulation and a Predator II blowing machine (the same blower you'd get from Lowe's). It packed to 3+ pcf no problem. I used the 4' aluminum attachment purchased from Regal to blow an entire stud bay through one slit in the mesh. I'd shove it down.. blow till the flow stops, push it down to pack.. back it up and blow again till it stops.. repeat the process working your way up. Just have to do the math to make sure you're using enough bags of cellulose.
I did have a problem with the first machine clogging the hose... clogged 3 times or so right off the bat. and it's a bee-ach to get the hose unclogged. Brought the machine back and got a different one. Worked way better... I don't think the second machine ever clogged once. So watch for that... I doubt the big boxes maintain the equipment all that well.
Blowers
Around here, the big boxes both sell "Cocoon" brand cellulose insulation and if you buy $200 of it, they will loan you a blower provided by Cocoon for free for one day. The round one is for attics and the rectangular one is for walls. But Home Depot's rental department also rents an Intec Force 2 which is a much better machine for doing walls if you want to accomplish " dense-pack".
Nozzles and insulation density
It is much easier to achieve higher insulation densities if you use a hose that you insert into the cavity rather than use a nozzle that you hold up to a hole. The reducer that abruptly transitions from 2 1/2 inch to 1 Inch will tend to clog. A better approach is to use a shop vac conical nozzle that tapers over a distance of about 8 inches. Using the conical nozzle inserted into holes in the sheathing, I achieved a density of about 2.3 lbs/cubic foot. When I used a swivel nozzle, made from a 1 1/4" plastic pipe ( tailpiece that goes under a sink) the cellulose density increased about 10-20% , perhaps from 2.3 lbs per cubic foot to 2.7 lbs per cubic foot. If I were to use a swivel nozzle again, I would use a 1 1/2 inch pipe because larger nozzles don't clog as easily as smaller ones. People who stick a hose in the wall report achieving densities of over 3 lbs per cubic foot, so that seems to be a much better way to go.
Insulation
The posters on Breaktime that do quality work ( like Mike Smith) and some insulation professionals recommend using insulation that is treated with 100% borate. It is somewhat more expensive than the material sold at the big boxes and is available from insulation supply houses.
Info on how to do it.
The Tauton book " Insulate and Weatherize" by Bruce Harley has a lot of good information.
Also check out http://www.karg.com/pdf/Presentations/Dense_Pack_Cellulose_Insulation.pdf"
Al Smith
I avoid the "free" cocoon blowers when I buy cells from home depot. They also have a force2 which works OK. The rental dept at my local lumber yard rents a force1 (oddly they don't sell cellulose) which has a much bigger motor and weighs a ton, but blows a little better. The serious machines are not available around here.I find I can affect the density a whole lot by how much I work the hose when blowing. I usually run a hose into the bay up to the top of the cavity, then back it out as it stalls. By jamming the hose further back up into the cavity when it stalls you can pack it tighter, kind of like using the hose as a powder rod in a muzzle loader. When I get to my insertion point which is usually halfway up the wall, I turn the hose around, jam it down to the bottom of the cavity and back my way up from there. I've gotten up as high as 4 lbs/cf when I get zealous with the ram-rodding. That's too dense though. Makes it hard to get the sheetrock on after.I have a whole bevy of hoses, starting at 2" down to about an inch. Some PVC, some black well pipe. The black well pipe works well because the built-in curve aids in snaking it into the wall. I also have the 4-foot aluminum nozzle you can get from regal. That works well for deeper cavities like 2x10, 2x12 rafters.Steve
Al,Great link to that PDF. Thanks.Steve
I am starting a siding project this week. Tear off the slate siding, cutting holes in the old lap siding. Any suggestions as to getting this insulated the most efficiently without tearing down to the sheathing? Has anyone tried using a small camera to make sure cavities are filled?I've blown from the inside into walls and I am not sure that the cavity's were filled to there entirety.
The easiet way I found to make sure I was filling all the way when doing it blind was simply multiple holes. One low, One middle One high. stick rags in the upper two and blow the lower until you get resistence, pull the middle rage and blow the same way then finish with the upper. Works fine plus the extra holes give the air a way out so you get a denser pack.
My '71 house has 2" thick faced fiberglass in the walls -- is that dumb or what???Has anyone used a cellulose blower to fill the stud bays in a home such as mine???
http://www.retrofoam.com/
The closest Retrofoam dealer is 500 miles away!
A bit picky aren't ya?
You make a good point ... I should not assume anything ... maybe he would like to stop by "on his way home"
A few years ago, maybe 20 by now, I used to blow cellulose into walls with minimal fibreglass insulation. Works fairky well.
Did you put a nozzle on to a hole in the wall or did you insert a tube/hose into the wall. If you used a tube, do you remember approximately the diameter?Thanks,Al
Nozzle in the whole. I believe it was 1.5".
Shoot, it was 20 years ago, I'm lucky if I remember last week!>G<
I have not done that but I think that I saw a video on a foam company web site where they added slow rise foam into bays that already had some fiberglass bats in them. I would probably contact my local insulation company and ask them for advice, specifically is this something that they can do and is it something that they think that I could do.
Lots of good advice and tips, a big thank you to all!
loews has a new machine called the artic cat seems like it is better then most go to the owens corning web site . the machine has a shut off on the end of the hose