My DIY cellulose wall dense pack experience
 

I had been planning this update to my house for a long time so now that the dense packing is done I thought I'd relate my thoughts and experience about it. I had a terrible time finding local outfits that had the cellulose blowers that I needed to rent or that had any expertise whatsoever. I called all the intown lumber yards and they didn't even have cellulose, much less a rental blower available. The next closest businesses were 45 minutes away and I called them and they didn't even know what I was talking about. The hardest part about these conversations is that the people I was talking to didn't know that they didn't know, so I kept getting non-useful suggestions from them instead of them admitting that they didn't know. Often these conversations would take 20 minutes before they would finally capitulate that fact. Very exasperating.

At one point I gave up and decided to contract it out. I called all the local insulation contractors only to find out that none of them, and I mean none, would do it the way I wanted. I had put up Insulweb netting on the inside walls of the perimeter of the house so I could see how the walls were filling. This is really the best way to quality check that you are not skimping on areas. All the contractors refused to work with me on that method and would only do it if I put up drywall first and they would pump it in from holes on the exterior walls. You just can't get the job done as good that way. My house has diagonal stud bracing on the corners and hidden headers where old windows installation have been covered up and it would have played havoc
with any blowing. I'm sure other older houses have the same issues.

Finally I decided to called the distributor of the largest blower manufacturer, Intec, and he was very helpful. He told me which rental models had the power to do what I needed, (Cyclone, Wasp, and Force 1-3 blowers), and the nearest places that had them. It turns out that one of the lumber yards I'd called that was 45 minutes away DID have the needed blowers, 3 of them, and they actually knew what they were doing. The person on the phone just wasn't in the correct department and did not know that he wasn't in the correct department or which department was the correct one. So if any of you out there planning to do this job do yourself a favor and call the blower distributor and find out if anything is available for rental in your area before you do anything. I ended up being lucky to have it available locally and as people say, it's often better to be lucky than good.:thumbup:

I did the living room, kitchen, and second bedroom. I didn't use the lip stapling method as I wanted to get as much insulation in as possible. With lip stapling the convexity of the bulging insulation starts in a bit from the outside of the studs So I stapled the netting flat to the studs and stretched it as tight as possible. Here you can see the bulge after blowing:

http://ecorenovator.org/forum/attach...1&d=1396032891

I decided it was best to buy an insulation roller and use it to flatten the insulation out. If you don't go this route and you don't use lip stapling you won't be able to get the drywall flat. It's really easy to flatten out the insulation with a roller. Here's what it looks like after being rolled:

http://ecorenovator.org/forum/attach...1&d=1396032891


Overall it was a very satisfying operation once I got to actually putting it in. I estimate that I put in a density just above 3lbs/ cubic foot. Once I rolled it flat the insulation made things a lot quieter inside the house. It was definitely noticeable and I attribute it to the fact that rolling pushes the cellulose into all the nooks and crannies that the regular blowing process misses. That is the difference between using netting and cutting holes in the exterior walls and blowing against rigid drywall. While you can't get the consistency with that method you can pack it really tight. That doesn't work as well with netting because no matter how tight you stretch it will still bulge. It's just the nature of the beast. Use that fact and just plan on compressing it by rolling it. It works really well and ends up being very consistent and of adequate density.

Great post!

Very useful information and photographs.

Thanks,

-AC

Exeric,that job looks good. Where did you find the "Insulweb" ?

InsulWeb

You'll also need some kind of hose to attach to the hose that comes with the blower you rent. It should be smaller in diameter than that hose. You just snake it down or up through the hole in the insulweb and gradually bring it back toward you filling in the volume that the hose itself took up with cellulose. Just using a nozzle pointed through the hole won't work if you are trying to pack it densely. So you'll need a reducer to connect the smaller hose to the larger. JR sells all those things.

I just used a 2" inner diameter shop vac hose attached with 2 hose clamps to a 2" to 2.5" reducer. It worked fine. It also helps if you have a wide crown pneumatic stapler instead of a narrow crown stapler. The insulweb tends to blow through the narrow crown staples because there just isn't as much material held beneath the staple crown. It just a convenience more than a neccesity, especially with the cyclone that I used, because it is lower power than some of the other blowers.

Exeric. Thanks for the link

Great write up and tips. I'd like to have a go at blowing my own insulation in too. I paid a guy to do my office and I'm happy with the results, but next time I want to do it myself. Actually I wanted to do it myself, but ran into the same problems you did with not being able to find a machine anywhere. I'll follow your advise when I'm ready on my next project, thanks!

Thought I'd post an addendum. I previously said that I thought I'd put in just over 3lbs of cellulose per cubic foot. That was just based on a rough uncalibrated estimate of how soft it seemed to me. I did a more accurate assessment now and I thought I'd run through it for you.

linear perimeter wall (2x6) = 89ft
area of perimeter walls = 89 x 8ft high = 712 sq ft
area of windows and doors to be subtracted = 160 sq ft
total area of perimeter walls = 552 sq ft
total volume of 2x6 perimeter wall = 552 x .46 ft thickness = 253 cubic feet

linear interior walls (2x4) = 22ft (for accoustically treated stereo room)
total volume of interior walls = 22 x 8 x .29 = 51 cubic feet

volume of all walls = 253 +51 = 304 cubic ft
adjustment for framing lumber = 304 - (304 x 20%) = 243 cubic ft
total weight of cellulose used = 45 bags at 19 lbs each = 855 lbs

lbs/cubic foot = (ta da) 855lbs/243cubic ft = 3.5 lbs per cubic foot

I think 3.5 lbs per cubic foot is good. That's good enough that it won't settle over time. And people should understand that it was done with an Intec Cyclone which is a very garden variety blower that can be found at most Home Depots. You just have to make sure that the slide gate , the thing that sets the proper ratio of cellulose to air, is set properly. The lower power blowers like the Cyclone have to meter the cellulose to the limited air supply.

So bottom line - YOU CAN DO THIS.;)