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Insulation question
- Thread starter 64auto
- Start date
Provided there is not a vapor barrier between them, yes it probably is. In other words, the 2nd layer should be unfaced insulation. If it is "faced" (meaning it has paper on one side) than it creates a 2nd vapor barrier.
Good reading material here on insulation:
http://www.dixieline.com/images/a-temp/mar07/JMRP00010B-ConsHmSBroch.pdf
Good reading material here on insulation:
http://www.dixieline.com/images/a-temp/mar07/JMRP00010B-ConsHmSBroch.pdf
boiler7904
Well-known member
Shouldn't be a problem as long as there is only one vapor barrier (assuming the garage or attic is heated and the other is not). The other thing to make sure of is that he doesn't compress the insulation. 1" of compression starts to really cut into the insulation's effectiveness. If they'll both be conditioned year round you don't need a vapor barrier at all.
The only real thing it did was increase the contractor's labor cost since he had to do it twice - I wouldn't pay that extra (if requested) since he chose to do it that way. He probably had it left over from another job and wanted to get rid of it.
The only real thing it did was increase the contractor's labor cost since he had to do it twice - I wouldn't pay that extra (if requested) since he chose to do it that way. He probably had it left over from another job and wanted to get rid of it.
Thats the problem there is a vapor barrier both have the paper backing. The upstairs and down stairs will be heated and cooled sepratley. I do not plan on heating or cooling the upstairs all the time but i am sure this will change if I turn it in to living space. What will the double barrier do?
Potential moisture problems is what you are looking to avoid. If there is a 2nd vapor barrier, moisture can get trapped thus leading to mold and other problems such as rotting wood, etc.
Just because the guy is a contractor does not mean that he knows how to do it right (or wrong). Before doing ANY home improvement project, either by myself or by hiring it done, I spend at least an hour or two researching it on the Internet. I do NOT want to be caught by any surprises later when doing a costly upgrade (of any sort).
http://www.buildingscienceconsulting.com/resources/foundations/Basement_Insulation_Systems-2002.pdf
Just because the guy is a contractor does not mean that he knows how to do it right (or wrong). Before doing ANY home improvement project, either by myself or by hiring it done, I spend at least an hour or two researching it on the Internet. I do NOT want to be caught by any surprises later when doing a costly upgrade (of any sort).
http://www.buildingscienceconsulting.com/resources/foundations/Basement_Insulation_Systems-2002.pdf
Last edited:
boiler7904
Well-known member
Thats the problem there is a vapor barrier both have the paper backing. The upstairs and down stairs will be heated and cooled sepratley. I do not plan on heating or cooling the upstairs all the time but i am sure this will change if I turn it in to living space. What will the double barrier do?
The dew point of the assembly will end up in the middle of insulation. That's where your problems will start. The insulation will get wet and then the framing will get wet. Dark and damp framing lumber is a great place to grow mold especially in summer.
I'd be having it ripped out and replaced as designed at the contractor's expense. Does your area require an insulation / infiltration inspection prior to covering with drywall or other sheathing? If so, the inspector should red tag you as soon as he sees that.
64auto,
I don't know how else boiler7904 and I can explain it other than the way we already have. You do NOT want faced insulation put on top of faced insulation for the reasons we have listed (moisture problems, mold growth, wood rot, etc.). You CAN put UNfaced insulation on top of the first course of faced insulation (faced side of first course toward finished space generally). It is generally put in perpendicular to the first course. Look at the links I have already posted for photos and more details.
I don't know how else boiler7904 and I can explain it other than the way we already have. You do NOT want faced insulation put on top of faced insulation for the reasons we have listed (moisture problems, mold growth, wood rot, etc.). You CAN put UNfaced insulation on top of the first course of faced insulation (faced side of first course toward finished space generally). It is generally put in perpendicular to the first course. Look at the links I have already posted for photos and more details.
6768rogues
Banned
If you are planning to heat/cool both spaces, either at the same time or different times, I would not use a vapor barrier at all. You are essentially insulating an inside wall.