Replies

1. GBA Editor
   Martin Holladay | Feb 14, 2017 04:14am | #1

   [Note to GBA readers: Enviro-Dri is a brand of liquid-applied WRB.]

   Michael,
   You are unlikely to notice any difference in comfort between open-cell spray foam and dense-packed cellulose.

   We can't comment on "long-term payback" if you don't tell us whether one of these insulation materials costs more than the other. (In any event, there is unlikely to be a performance difference between these two.)

   A few points:

   1. Unless you install exterior rigid foam, the performance of either type of insulation will be undermined by thermal bridging through the studs.

   2. No matter what type of insulation you decide to install between your studs, you need to come up with a plan to limit air leakage. Ideally, you will ask your builder about air barriers, and will confirm your home's air leakage rate with a blower-door test.

   3. You may be interested in reading this article: How to Design a Wall.

   -- Martin Holladay

2. 
   Auxzillium | Feb 14, 2017 06:43am | #2

   Martin,

   I was under the impression that Enviro-Dri stops 90% of air infiltration. Do you recommend another product?

3. GBA Editor
   Martin Holladay | Feb 14, 2017 07:00am | #3

   Michael,
   You're right -- Enviro-Dri will be a major component of your air barrier. However, you still have to pay attention to penetrations -- electrical penetrations, hose bibs, window openings, and door openings. Moreover, you also have to come up with a plan for transitions (wall air barrier to ceiling air barrier, foundation air barrier to wall air barrier).

   Assuming you get those details right, you'll be in good shape.

4. 
   Auxzillium | Feb 14, 2017 07:02am | #4

   Thanks Again!