I finished off the prep work in the attic and blew in all the insulation on Saturday. We ran the blower for about 4 hours, and we put about 1700 pounds of the stuff up there. I tried to get it at least 10″ additional cellulose everywhere, which makes it R40 or better.
Once we got the machine and the method figured out, it was pretty simple. I just had to work on my knees for a total of about 6 hours. If I weren’t used to it, I assume it would be fairly painful.
The hose is rigid enough to push it where you need it to go without crawling around too much. I was able to push the hose into the base of the baffles and kind of dense-pack it in there. This will increase the R-value in the thinner space, and keep the baffles from ever falling loose.
Home Depot let me use their machine for free ($50 deposit), and it worked great. A number of posts online said the big-box store version didn’t work very well – I’d have to disagree with that. We had no issues, and it could pump it out just about as fast as my son could load it in. It came with about 100′ of hose, which was plenty.
We set up a work table and broke up the bales into smaller pieces before loading them. That was the key to making it run smoothly. If it were mine, I’d pull the safety grate out and put a box extender up about 16″. I think you could break up a bag into a few large pieces and throw the whole thing in.
There really isn’t much technique to blowing the cellulose in. You just point the tube and let the machine do the work. I marked up 10″ on the walls and a number of the trusses, and kept blowing it in an area until the marks were covered up.
You can see from the video that it’s a bit dusty but less so than I thought it would be. I used a good quality N95 mask and didn’t breath much of anything in. I think my son got as much dust from loading it as I did from blowing it – and I made sure he had a mask on.
I’m fairly sure I had the cellulose depth closer to 12″ in the center of the attic, so I ran out with about 100 square feet to go. This is fine since it just ups the insulation value and air control. We ran to the store, got 6 more of the 19 lb bags, and finished everything off.
I left most of the deck up in the attic uncovered. The insulation under it is about R30 – so not too bad. I wanted to keep it open since it allows access to most of the solar panel wiring from the breaker panel. I think I’ll wait for a good find at the Habitat for Humanity ReStore on fiberglass batts, and put another R15 or 20 on it. They will be easily moved if I need access up there.
So in summary, I’m glad I did it. I probably spend 20 hours in the attic with everything I had to do – but I’m not planning on going up there for quite a while. Next, I need to install the eave vents and put a ridge vent on the roof.