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Circle-D Posted: May 28, 2011 10:35 PM	crawlspace Hi Mason, I have an energy auditor that is recommending to a customer to have his crawlspace walls and underside of floor foamed. There are heat ducts in this crawlspace, which he is also recommending to insulate (with something). Although I agree with the crawlspace walls and ductwork getting insulated, I am of the feeling that the underside of the floor should remain uninsulated, thereby creating a conditioned space. This crawlspace is about 2800 sq.ft. and has a dirt floor. Shouldn't someone be putting down a poly vapor barrier and sealing to the walls also? If you insulate the walls AND the floor won't these ducts be in a cold space thereby reducing efficency? Thanks for a great conference in N.H.
mason Posted: May 29, 2011 01:59 PM	Skip, I agree with you. Makes more sense to me to place a vapor retarder on the floor, insulate the walls and leave the underside of the first floor alone, if the ducts are in the crawl space. I am out of town this week or I could send you some good articles on insulating basements. However, go to buildingscience.com and search their web pages for some basement and crawlspace articles. I think they will help with your client
Tim O'Keefe Posted: May 29, 2011 10:16 PM	Would simply installing a poly vapor barrier on the floor (ground) in conjunction with the foam insulation on the side walls be sufficient to consider the crawlspace "conditioned"?
Posted: May 30, 2011 05:47 AM	well,,, semi-conditioned anyways,, conduction,,convection,,radiation,, phynny how that physics stuff works,, it is amazin at how effective spf is at isolating one environment from the other in the crawlspace scenerio...imagine,,seamless from floorboard above,,down rim joist and plate assembly,,contigious onto the crawls sidewalls,,right on down to the ground/poly/slab,,not a seam or crack or break in the insulation envelpe,,, true isolation of one environment from the other,,insulation btw,,,2" down the side and right on across the grade,,we dont need no stinkin poly,,again,,side to side seamless,,vapor retarding membrane,,soil borne gas retarding membrane,,accomodating to weird footings,,chimeny stacks and other pennetrations,,and did we mention and insulation layer as well??

Author

Comments

Circle-D

Posted: May 28, 2011 10:35 PM

crawlspace

Hi Mason,
I have an energy auditor that is recommending to a customer to have his crawlspace walls and underside of floor foamed. There are heat ducts in this crawlspace, which he is also recommending to insulate (with something). Although I agree with the crawlspace walls and ductwork getting insulated, I am of the feeling that the underside of the floor should remain uninsulated, thereby creating a conditioned space. This crawlspace is about 2800 sq.ft. and has a dirt floor. Shouldn't someone be putting down a poly vapor barrier and sealing to the walls also?
If you insulate the walls AND the floor won't these ducts be in a cold space thereby reducing efficency?
Thanks for a great conference in N.H.

mason

Posted: May 29, 2011 01:59 PM

Skip,

I agree with you. Makes more sense to me to place a vapor retarder on the floor, insulate the walls and leave the underside of the first floor alone, if the ducts are in the crawl space.

I am out of town this week or I could send you some good articles on insulating basements. However, go to buildingscience.com and search their web pages for some basement and crawlspace articles. I think they will help with your client

Tim O'Keefe

Posted: May 29, 2011 10:16 PM

Would simply installing a poly vapor barrier on the floor (ground) in conjunction with the foam insulation on the side walls be sufficient to consider the crawlspace "conditioned"?

Posted: May 30, 2011 05:47 AM

well,,,
semi-conditioned anyways,,
conduction,,convection,,radiation,,
phynny how that physics stuff works,,

it is amazin at how effective spf is at isolating one environment from the other in the crawlspace scenerio...imagine,,seamless from floorboard above,,down rim joist and plate assembly,,contigious onto the crawls sidewalls,,right on down to the ground/poly/slab,,not a seam or crack or break in the insulation envelpe,,,
true isolation of one environment from the other,,insulation

btw,,,2" down the side and right on across the grade,,we dont need no stinkin poly,,again,,side to side seamless,,vapor retarding membrane,,soil borne gas retarding membrane,,accomodating to weird footings,,chimeny stacks and other pennetrations,,and did we mention and insulation layer as well??

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