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Discussion Starter #21
dang, my neck is hurting AGAIN.

OP, you have a lot of working room up there. i have seen houses with 1/2 that(roof pitch).

btw. when buying the cellulose. buy a LOT of it. you "think" you need 20 bags = buy 40. wait, no, buy 50-60 bags.
So - i did a rough estimate of my second floor area, assuming that it would be the area that needs to fill the attic.

1100 sq. ft is a rough estimate of coverage, how many of these bags do it need. knowing that i already have 5" to 7" in place already.

http://www.lowes.ca/greenfiber-blown-in-insulation_15017_m14021.html?rd=A
 

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just a guesstimate. but i would say that you would use 70-80 bags, and then want more. i did about 800sf to about 9" and ate up 30 bags. and i had some old insulation under parts of that 800sf. just to top off that area, i figure i would need about 40 bags.

my advice = buy way more than you "think" you need. then, if you do not use it all. just take back what you do not use.
 

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That is fiberglass that you have. It looks fairly clean, but it will irritate your skin and throat so wear a mask, gloves, and either some junky clothes or a tyvek suit (be prepared to sweat if you do that because it doesn't breathe). I would add FG rather than cellulose since that is what you already have. If you can figure out where your soffit vents are, just stuff the baffle down over the fg batting to let that airflow through. Leave the fg in place to prevent wind-washing of the insulation. I would spend the a day doing that and airsealing the major chases (chimey, electrical boxes, drop soffits, etc) and then come in the following day and blow over it with the additional insulation. You could hit all of the top plates etc as well (would be ideal), but it is not gonna be easy with that blown fg in there.
 

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Discussion Starter #24
So, i did it, after all the chatting and learning, i did it, i added one rafter (with baffle) vent. lol

check the picture out.

Here was my experience, first off, dress up in junky clothes, wore a mask, hat, and gloves, got a plank of wood (need more than 1) - man did it get hot

Used a leaf rake to move the FG blown-in insulation away from the corner. - great tool for attic work and moving blown-in insulation.

The FG insulation was used as a wall that touch the rafter and the joist, so no air flow (or at least block). I removed the FG insulation and behind the insulation itself was a little dirt, but the soffit vent itself was clear open.

I did notice something interesting, and you may see it in the picture, there is a piece of plywood acting as a rafter vent (i have maybe 4 of these, across the entire attic).

After cleaning out the area, i stapled the rafter vent in, it didnt fit perfectly or even flush, it require some bending to "squeeze" in between the rafter joist.

i noticed that i don't have a ridge vent, but circular holes in the rafter itself, that are attic vents. (perhaps 3 to 5, didnt count them all)

I put back the FG insulation wall back into the newly created dam and brush back and puff up the blown-insulation.

Thoughts? suggestions? validation?

p.s. to the people that do this as a profession, you have found another humble person that respects what you do.
 

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Looks like you are on the right track :) It sounds like you have regular box style roof vents as opposed to a ridge vent. Those are perfectly adequate provided that you have the correct amount.
I see that plywood tacked on to create a cavity. Does that extend down between the joists to block the insulation from falling into the soffit?
 

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Discussion Starter #26
Yes, i could see the soffit vent clearly.

I called an attic insulator and he told me that i dont need rafter vent in every bay, is that true?
 

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Yes, i could see the soffit vent clearly.

I called an attic insulator and he told me that i dont need rafter vent in every bay, is that true?
Maybe maybe not. In order to tell you must figure out the airflow through the vents then match to the outflo in your attic vents.

Buildingscience.com might help you:)
 

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Just read this whole post and noticed that no one mentioned insulating the attic hatch. I am assuming that you enter the attic through a ceiling hatch? If so, make sure to insulate that as well using foam boards glued together to achieve whatever R value you need. They sell a special foam adhesive to use for that. Then when you have your hatch all insulated, apply a weatherstripping along the perimeter where the hatch sits to prevent heat from escaping into the attic. I did mine last year, which was a huge improvement as the builder used a plain piece of wall paneling cut to fit the hole. I used R10 rigid foam and glued three pieces together and glued it to the plywood hatch. I probably should have added a fourth piece of foam board but can do that this spring to bring it up to R40. The snow on my roof stays there a lot longer now. :thumbsup:
 

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Discussion Starter #30
Thanx for the information everyone. Appreciate everyone's insights. I dont remember if i asked this earlier or in another post, but am working out the math between doing it myself and hiring a professional. So, could someone help me calculate the number of bags i need. I figured i need about 50 to 60 bags of the cellulose.

Here is what i have

1300 sqft
7" currently of blown-in FG


If i use http://www.lowes.ca/blown-in-insula...isku=8778085&linkloc=cataLogProductItemsImage how many would i need to get to R50?

i figured about 50 to 60 bags, is that right?

PTMD

as for the hatch cover, it has about 8" of rigid foam already, but i have to reinstall the weather stripping.
 

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i say = always buy WAY MORE than you think you need. then, if you do need it, its there. if you don't need it, just take it back.
 

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Discussion Starter #32
i say = always buy WAY MORE than you think you need. then, if you do need it, its there. if you don't need it, just take it back.
good point, but i am trying to calculate my cost versus the professional. See how much more it will cost me.

Doing my own break even analysis. So, yes, you are right about buying more bags, but what is the rough estimate of bags.
 
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