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Cellulose Blow-In Questions

gabe24's Avatar

Join Date: Nov 2005
Posts: 80

01-18-06, 05:51 PM   #1  
Cellulose Blow-In Questions

I currently have about an inch and a half of compacted cellouse in my attic. There is not a vapor barrier below the insulation. I also have a feeling the insulation is compacted due to the lack of a vent in the attic. I'm planning on adding a power vent with a thermostat and humidstat before reinsulating the attic to a r30+ value. Here are some questions I have.

1) Do I need a vapor barrier below this compacted cellouse that is already there?

2) Do I need to remove the old cellouse thats compacted before I add more?

3) With proper ventilation will the new cellouse compact like the old insulation did?

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doug thomas's Avatar

Join Date: Jan 2006
Posts: 104

01-19-06, 06:45 AM   #2  
1) A vapor barrier is used to reduce the amount of necessary ventilation. If you house is already functioning well without ventilation, and you will be ADDING ventilation, you probably won't need to worry about the vapor barrier.

2) Only if it's moldy. Is it moldy?

3) Probably. But that's ok, because once you reinsulate, most of your heat loss in the attic will be happening through air leakage. The more it compacts, the better it acts as an air barrier. Just keep adding more cellulose

Last edited by doug thomas; 01-19-06 at 07:37 AM.
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