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Discussion Starter #1
I want to use blown in insulation in the attic. Most of it already has a floor. TnG flooring over fiberglass insulation. 2x8 joists. The fiberglass insulation is probably packed down to 2" so there is several inches (4+") of air between the fiberglass and the under side of the floor. I would like to fill the gap in with blown in without pulling up the whole floor.



OTOH, When I did a rewiring, I did pull up several 1x4s every 4-6 feet so I could pull wires. Is there a decent way to blow in the insulation under the floor?? I am thinking I have access about every 6 feet. Not sure if I can stuff a hose in there and reach the end. How far can a hose shoot cellulose in a cavity??



The blower hoses are 2 1/2" or 3" so it will be a tight bend to get the hose through the floor where the boards are pulled. 1x4s.



Any tips or ideas??
 

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Your approximate location helps with the insulation advice.

Are you looking at blown in fiberglass or cellulose?

Drilling holes to blow in insulation is a normal install and on the floor they could be left open. I believe holes smaller than 3" are used depending upon the equipment.

But, that wood floor can be an issue. One, it limits the amount of insulation and two it becomes a condensation surface. When it gets cold any moisture vapor coming up from below may condense at that point.

Baffles to maintain ventilation, and something to block the new insulation from filling the soffits.

Bud
 

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Discussion Starter #3
Your approximate location helps with the insulation advice.


>>>Northern Indiana


Are you looking at blown in fiberglass or cellulose?


>>>Celulose


Drilling holes to blow in insulation is a normal install and on the floor they could be left open. I believe holes smaller than 3" are used depending upon the equipment.


>>> I hate to drill more holes. I do have some access points, boards pulled up. The floor is a walk way and storage, so I hate to leave open holes. Maybe an option for the less traveled areas.


But, that wood floor can be an issue. One, it limits the amount of insulation and two it becomes a condensation surface. When it gets cold any moisture vapor coming up from below may condense at that point.


>>>Not that worried about condensation, A lot of ventilation there.


Baffles to maintain ventilation, and something to block the new insulation from filling the soffits.



>>> No soffits, so nothing to block. Older house 70 plus years. It has large gable vents and a good ridge vent.


Bud


>>> Basically looking for a way to fill in under the floor with a insulation blower.
 

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Discussion Starter #6
Just giving some info to anyone following this post. Always good to find out how it turned out. The cellulose blower worked very well. I pulled up a section of flooring about 12" wide. (wall to wall) I did that in several upstairs rooms. The blower used a plastic hose about 3 inch diameter. I was able to put a bend in the hose and shove it under the floor. Even with the fiberglass insulation there, I was able to shove the hose maybe 8 to 10 feet under the floor quite easy. Then I could run the hose in the other direction and cover a larger area. Only problems were where an electrical wire crossed. Even so, the blower would throw the insulation several feet. It was just a little hard guessing how much it was filling the space. I was getting used to the change in the noise of the blower when it was starting to pack the insulation.



It worked out great, except for the unreal mess of dust and insulation everywhere.



BTW it was not quite packed fiberglass insulation there already. It looked like the original installer used 3-1/2" fiberglass roll insulation in a 2x10 joist.
 
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