Leafblower/shop vac to move blown-in insulation for air sealing
Like most houses, my attic floor is poorly air sealed. The builder/homeowners of years past have tried to compensate for this with lots of blown-in insulation. I’m considering air sealing and adding more blown-in (either fiberglass or cellulose).
The problem, of course, is the existing blown in stuff which is everywhere. I’d really like to avoid removing it all, as theres probably hundreds of dollars of insulation that is “fine” (i.e. some of it is compressed, and plenty of debris — but its there). The blown-in is a mixture of the original dark brown/gray stuff (I believe that is rockwool?) and more modern white fiberglass
I’m considering working in a zone-by-zone fashion, using either a mulching leaf-blower or a shop vac, sucking one area of attic floor clean and dumping the insulation into another part of the attic. Air seal the newly-exposed area (as well as doing some other repairs– mainly installing/fixing soffit baffles), then use the same technique to move the insulation back over this area.
I’ve seen videos of people using dust collectors to fully remove the insulation (i.e. through 30+ feet of hose into a dumpster), but I wouldn’t think I’d need that much horsepower if I’m just moving the insulation several feet over.
I could just manually move it using a rake/my hands, but that sounds pretty awful and this technique would have the added benefit of “re-fluffing” the insulation, which it could sorely use. Plus, the should be relatively clean/dust-free, so spray foam/caulk should adhere better.
Any thoughts? I’m sure I am in for a really miserable job, but I’m already imagining the satisfaction factor! 🙂
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Do it by hand- Just enjoy the terrible working conditions - be glad you don't do this for a living.
I had blown-in removed from a attic I was renovating. They used an electric leaf vacuum with a hose attached to the discharge side. They use it for final clean up. The bulk was removed with trash bags and dust pans. I think the problem is where do you put the stuff you move out of the way so it does not have to be scooped it up twice.
I've done exactly that in the past! I used a Tora blower / vac in vacuum mode to strip loose insulation from one segment of my attic in order to dump it in another.
I will never do that again.
The problem is one of scale. There was FAR more cubic feet of insulation than I had imagined, even in a very small part of the attic. The leaf vac bag would fill up extremely quickly and with only a barely visible dent in the insulation level. This meant trip after trip after trip. Super tedious work! I tried to get more bang for my buck by attaching a very large trash bag (90 gallon or so) to the vac instead of the leaf bag. That didn't really work since the vac requires that the bag be porous to air and the trash bag mostly certainly wasn't.
I had notably better luck just using an aluminum wide shovel to just shovel the insulation into the large bags. That only sent so far, though. I couldn't really do it where there were any wires. Still, that plus the leaf vac combined did the job.
When time comes to do it again, I will either get a much more robust vacuum (like one of those dust collectors) or I'll just tamp down my "never throw anything out" impulses and hire a team to remove it!
I think a key distinction here is that I am not actually removing the existing insulation from the attic space. I am just moving it to give me access to the top plates, wire penetrations, etc. then moving it back. I understand the hauling bag after bag would be incredibly tedious.
I think what I might need to do is place some plywood 'landing pads' in the general area of the exhaust from the blower/dust-collector/vacuum, that would help to support the insulation. I'm a bit concerned about the weight of a mountain of insulation.
Ive done air sealing retrofits on hundreds of houses with a crew. Obviously wanted efficiency so early on I thought a leaf vac would give me an efficiency edge. It will not, extremely dusty.
Big plastic dustpan is what we use and wing it to the side for wall plates. Fans and light boxes we clear by hand, only takes a second and doesnt have to be completely clean. We kick it back a little bit and when Im installing I can use my insulation machine to flatten the existing when we are blowing cellulose over the top.
Also tried a plastic shovel, abandoned that idea as well.
Super useful to know. Thank you. I suppose sometimes you can spend more time trying to save time than just buckle down and do it. I tried a bit with a crappy dustpan today and I think you might be right. I think I'll go dustpan shopping and see if I can find an extra wide (23" would be awesome!) one to fit right between the trusses.
I'm in a similar situation to you and was pleased to find this thread. Did you go ahead with the sealing? How'd it go? Any lessons worth passing along to future dustpan wielders?
I just use a snow shovel, lightweight plastic kind with telescopic handle.
you're really just pushing it aside and moving it back.
I found this thread after I completed my job. Terrible work. I also used a shovel. There were areas with matted down insulation that after my air sealing I used a battery operated leaf blower to fluff and re-distribute. Worked great
I had to move a large volume of cellulose from one attic to the other and could find zero local contractors to do the work last year. What worked very well was a 1 hp wall mounted dust collector with 4" dust collector hoses attached. I had about 50 ft of hose on the suction side, and about 20 ft on the exhaust side. It worked perfectly well. I sold the 50' of 4" collector hose and dust collector after for about 150$ less than my cost.
Four tips.
1. Monitor the exhaust side and move the hose often. I hung the exhaust hose from the attic roof deck (a few feet off the ceiling) and just distributed after with a rake.
2. Sort a nozzle for the suction side using 3-4' of 4" metal duct to reach into eaves etc.
3. Use a furnace filter to block off your 2nd attic hatch (I just put a 4" round hole in it for the hose) so that blown air/insulation does not end up back in y0ur home. There is a lot of air moving with a system like this.
4. A full face mask respirator like the 3M 6900 series is nice to have for a job like this.
I could have used a dump bin or trailer (if disposing of the insulation) with the open end covered with filter cloth or support mesh, but in this case I just moved the insulation from one attic to the other. If you are dealing with an older attic with vermiculite (common here) then you'll want to test for asbestos first before touching anything.
I have used a rake in the past, worked pretty well. I was part of a job removing an attic worth of blown in from a large industrial building, we hired a large vacuum truck. Was worth the money.
For sure hire this job out if you can. I only resorted to DIY as the only company with a vacuum truck locally had no staff willing/able to do attic work.