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Adding Insulation to a floor


OldRanch's Avatar
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Join Date: Apr 2007
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07-27-07, 06:33 AM   #1  
Adding Insulation to a floor

Currently I am working on a garage conversion. I have my rolled insulation ready to go, but have a question. Which side should the paper face? It is a completely suspended floor over a crawl space concrete pad. I was thinking of putting 6 or 4 mil plastic down on the underside of the floor joists to help support the insulation and assist with moisture. Also, would my floor be adequate with 2 7/16 OSB overlapping each other? I am thinking of support (and $$$, I need to try to keep some costs down), since that would be amost a full inch of sub-floor with a laminant over top. Thank you for any help.

 
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adamplghtg's Avatar
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07-27-07, 07:19 PM   #2  
The vapor barrier is generally on the heated side of the building. I heard down south tho that the vapor barrier should be on the outside, not the inside, because the inside of the house is generally cooler than the outside. Also, don't put solid plastic under the insulation or it will be trapped between both vapor barriers and can't breath if moisture does get in.

Not quite sure about the 2 7/16 OSB tho. I don't quite understand.

 
OldRanch's Avatar
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08-03-07, 09:00 AM   #3  
Thanks for the reply. Another quick question though, when insulating the exterior walls, do i place the insulation over the wiring or under? Thanks.

 
Ed Imeduc's Avatar
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08-03-07, 09:16 AM   #4  
You dont say how deep this crawl space will be . You can put a 6 mile poly down on the cement over lap it 2ft and tape all seams. Put the insulation in the floor paper side to the room . Also any insulation in the out side walls the paper side goes to the room. On the wire in the walls try to fit the insulation around it with the paper =V/B to the room side.

 
OldRanch's Avatar
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08-04-07, 08:41 AM   #5  
Thanks for the reply. The crawl space is about 8-12 inches.

Just so I have this right...no insulation over or under wires, but laid with a section cut out where the wire runs.

 
adamplghtg's Avatar
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08-04-07, 11:14 AM   #6  
Try not to cut the fiberglass unless you have to. It will create space for air to flow through. Put it over or under the wires.

 
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