Need to insulate an attic floor. 3/4″ advantech on unheated attic floor, finished DW ceiling below.
Thinking about drilling holes in advantech in every joist bay then fishing the hose down through. Joist bays are probably 20′ long.
Will the blowe push cellulose 10′ or so?
Thanks.
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Replies
No -- not if you are using those free blowers at the home stores
Stick a piece of PVC on the end of the hose.
blowing insulation with a pvc pipe attched, will result in some of the biggest static electricity arcs you will ever see.
it's scary......................btdtthe older i get ,
the more people tick me off
Scary and brutally painful.
>>will result in some of the biggest static electricity arcs you will ever see.<<Been there, done that! Nearly knocked myself off the ladder a couple of times, nearly stopped my heart a couple of times. I've taken to running a ground wire to the PVC. Does the trick.
where do you run your ground? elec box,ground rod outside,back to the blower?
it's amazing how that creates so much static,seems i ought to be able to power something with it.the older i get ,
the more people tick me off
I would think the way to go would be to tape a bare copper wire along the length of the pipe, wrapping it around the end of the hose on one end, and allowing the end to dangle in the cellulose stream on the other. (Although better still would be to thread the wire though the inside of the pipe, somehow securing it to the walls at intervals so it wouldn't block the flow.)
This country will not be a permanently good place for any of us to live in unless we make it a reasonably good place for all of us to live in. --Theodore Roosevelt
Edited 12/4/2009 8:43 pm by DanH
>>where do you run your ground?<<Sometimes to an existing ground rod, sometimes to the ground on an electrical outlet with a specially modified extension cord that only has a ground prong on it (only after checking that the outlet is wired properly).Yes, it can be one almighty jolt. I swear I've had it affect my heart sometimes.Steve
Can you cut an oval/oblong hole and feed the hose down the bay far enough and extract the hose while blowing in; or are their wires and light fixtures blocking you path?
Cut the hole with a jig saw at a 45 degree angle. That way the plug will not fall thru, kind of like when you cut the top off a pumpkin. Make the hole oval so you can slide the hose down the bay like others said.
I did the exact same thing with free blowers. I used a spade bit and drilled holes every couple of feet and blew it in from these and then plug the hole with tapered plugs I bought at HD. Don't know if they carry them any more or not. but it worked well for me. I glued the edges and drove them home flush...no squeaks. On the other hand I also opened up a section of floor and replaced the patch of ply...squeaks. I know which way I would do it. Plus, with my method, I knew I had a dense pack. BTW you'll be surprised how much it takes if you do dense pack it.
Are you having the same problem I had? Insulation was installed in the bays only to the point of knee walls in attic/second floor but they didn't put any blocking in the joist bays at the knee wall so the air just circulated above my first floor cieling by convection and sometimes strong wind from one soffit to the other.
Something like these
http://www.jrproductsinc.com/shop/pc/viewCategories.asp?idCategory=105
Edited 12/3/2009 4:10 pm ET by cussnu2
It depends on how much air you are pushing through the hose with the cellulose. If you put in enough air and just a little cellulose it can fill more than 20'. With little air you might not get 5'.
Keep in mind that it will take a lot longer to fill the bays if you add a lot of air.
You are getting some good tips. You need to feed the hose in maybe more than 10 ft is my guess. Just like doing walls ... you stuff the hose in a long ways. If you have obstructions (e.g. a ceiling light fixture or J-box or plumbing), they will likely prevent the full blow.
A pro would track the volume installed w/ the cavity being filled to know whether you did the job or not (i.e. one bag of cellulose fills a given space w/ so much R-value).
Best approach ... drill your hole near the center and push the hose down both directions .... reduces your need to throw very far. This is done in walls, too. You drill somewhere in the middle and do the bottom first and then fish it upwards. No issues.
I should have made it clear that when I did it, I only drilled a 1 1/2" hole I think about every 3 feet. when I was done you couldn't stick you finger in the holes but this way will take you longer and use way more bags.
So far, no one has given the right answer: Cellulose will blow 200 feet in the wrong direction, but only 6 inches in the direction you want it to go.
I did cellulose straight out of high school in '76, in existing houses.
We were filling a wall cavity on a second floor roof, not paying a whole lot of attention to the time. The teenage daughter of the house came out screaming and cussing, we had filled her closet with a large amount of insullation. It was the day of her homecoming game and her freshly cleaned cheerleader outfit was hanging right where the gun was pointed!
Her dad had done some electric work and not patched the hole. Mike
Small wheel turn by the fire and rod, big wheel turn by the grace of god.
>>we had filled her closet with a large amount of insullation. <<Been there, done that. Cleanup was not fun.
Clean up was not fun. Agreed, but it was surprising how easily the clothes were dusted off.
That was a pretty good job, the owner/ salesman was my buddy's step dad.
We got 30 bucks an attic, 90 for the walls. Two man crew, we could do 3 attics a day or usually a house in a day, including patches.
Split the take 2 ways, Big money in '76 ; ^ ) Mike
Small wheel turn by the fire and rod, big wheel turn by the grace of god.