Blown-In or Loose-Fill Insulation

Fill the Whole Framing Cavity — Even Irregularly Shaped Ones

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Blown-In or Loose-Fill Insulation, including:

  • Design and build strategies
  • Necessary codes
  • Application how-tos
  • Using materials
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Thu, 02/02/2012 - 05:24

Response to Charles Eichenlaub
by Martin Holladay, GBA Advisor

In your climate, most building codes require a vapor retarder, not a vapor barrier, on the inside of your wall. You should avoid the use of polyethylene. Vapor-retarder paint (over the drywall) will work fine.

Of course, airtight construction techniques are much more important than whether or not you include a vapor retarder. Do your best to seal all air leakage points.

Here is more information on vapor retarders:

Vapor Retarders and Vapor Barriers

Forget Vapor Diffusion — Stop the Air Leaks!

Wed, 02/01/2012 - 23:02

Vapor barrier
by Charles Eichenlaub

I live in Northern Michigan. What about vapor barriers and cellulose in new home construction? I am building with a double wall 8-10" of cellulose.

Mon, 11/15/2010 - 09:24

Response to Bryce
by Martin Holladay, GBA Advisor

Thanks for your post. You bring up some important concerns. I discuss some of these issues, and more, in my recent Fine Homebuilding article, Blown Insulation for Attics: Fiberglass vs. Cellulose.

Here are the links:

Mon, 11/15/2010 - 09:13

ORNL Study
by Bryce

The article I have in my files from Home Energy, May/June 1992, discussing the ORNL tests, indicate that the R-value of the blown fiberglass began deteriorating at approximately 30 degrees F, due to convection currents within the product. I believe the University of Illinois arrived at similar information under testing they performed on blown fiberglass. From personal history, I can attest that homes with blown fiberglass have higher ACH under a blower door test and have higher energy consumption than similar homes with cellulose.

Tue, 02/02/2010 - 02:58

Either one
by Martin Holladay, GBA Advisor

1. Either product will work. If it were my own house, I'd choose cellulose.

2. Remember, more insulation is better than less. As long as you're installing more insulation, you might as well install as much as you can afford.

Mon, 02/01/2010 - 22:30

I need some help on insulation
by Ryan O'Dell

I built my house 4 years ago and used fiberglass blown-in insulation in the attic. I went up and found that the fiberglass has settled down about 4 in., so i am going to get more insulation to blow in. But do I use more fiberglass or do I get some cellulose and blow it on top of the old fiberglass ?

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