With fiberglass batts, should the vapor barrier (paper side) be installed towards the heated area of the house or not?
Vapor barrier towards the conditioned space.
It is generally printed on the vapor barrier itself.
The paper side goes to the conditiond space.
Vapor barrier towards the conditioned space. Towards the living space.
I knew I was right!!!THANKS!!!
How much did you win ? :mrgreen:
David, good site.
Do you guy’s find floor insulation that is installed too tightly compacted?
Around here they push the wire hangers with the bow to the top and it leaves the insulation about 2 inches thick.
What is the R-value of compacted fiberglass that is 2 inches thick?
Yes, Once in a while. Homeowners fail to realize that fiberglass insulation works on the principle of trapped air pockets. By compressing fiberglass insulation, it decreases the amount of air trapped in the material. For example, compressing R-19 (6 inches thick) into a 2x4 wall will give you an R-13 value. That’s why the manufacturers make a variety of thicknesses and widths.
Probably around R-7.
The R-value or insulating factor of insulation definitely changes as the insulation becomes compacted, loosing some of its effectiveness.
If there’s an area that is compacted due to the support wires being cut too long and it’s compressing the fiberglass batts, the compressed area looses it’s R-value because the density of the insulation has been compromised.
The support wires are only suppose to be ½" longer the the joist cavity width. Cutting them any longer will cause the compression that you are referring to.