Have you been advocating installing insulation in both destinations -- on the ceiling beneath the attic as well as in the sloped rafters in excess of the attic?
You question, "Could Icynene be inferring below that since our merchandise is an air barrier consequently it's got inherent Strength preserving gains that, when coupled with their insulation values equate to R-38?"
Not a soul is arguing in favor of the "conventional fiberglass-insulated house." Should you read what I've created, I advocate that each home be tested with a blower doorway.
As with the ASTM study, you will get no argument from me concerning the knowledge of employing closed cell on roof decks. Actually, I find only a few scenarios where by 2 lb. foam is smart in the slightest degree. Even so the ASTM review (no less than the portions you posted in this article and in other places on the net) have nothing to do with my remark.
I'm not obsessesd with comparing the worst accomplishing insulations to another while you said. I am attempting to comprehend your imagined process within your posting. Could you make sure you offer answers to my thoughts.
And that i must differ with the assessment (as I did above with Laverne's) that complete assembly testing is by some means considerably less precise or "dishonest".
Everything becoming explained, I am typically questioned to do HVAC loads and Electricity modeling for houses with spray foam. I've come to the summary that encapsulated attics *may perhaps* be cost effective for a few residences, in a few local weather zones, when there is no other option than To place HVAC from the attic (of course, that is the designer's read here fault, not the builder's).
Thanks for the small print on Nisson's review. I have been looking for additional info for months. Ought to have asked you earlier.
Signed by Viktor Ginic, a constructing science engineer at Icynene, the letter reads, “The air-seal advantage of Icynene supplies improved Strength efficiency above Significantly better R-value insulations that are air-permeable. The blower-door testing of airtightness of the homes insulated with Icynene indicates a mean air infiltration price 5.five periods reduce than a property insulated with mineral fiber insulation. Based on measured air infiltration and the number of Vitality analyses done, we have found that Icynene, mounted in accordance Along with the maker’s installation Recommendations to some nominal thickness of 3″ while in the walls and floors and 6″ in roof/ceiling applications will carry out far better thermally than R-19 and R-38 air-permeable mineral fiber insulation.
Many thanks for your clarifications; they are helpful. Get More Information With these clarifications introduced, I are convinced your placement and my position are not that much apart.
Martin, I've study quite a few of the posts and agree with much of Whatever you generate. On this subject you are dead Mistaken. I'm not an advocate of any foam mfg, I and an extremely significant proponent of not deceptive people today as you've carried out In this particular particular post.
Infiltration is a significant, but separate consideration. But I give spray foam no excess factors for producing that task less complicated. In any event, my residences will be tight.
However the core argument is seem. Bigger air tightness allows for considerably less R-benefit to perform also from an Electricity reduction perspective in the whole building. We being an market have to get away from Producer sponsored "details" and have some true non-biased independant study. Herein lies the problem.
(Nisson was EDU's founder and to start with editor; I afterwards took around The work.) The first of Nisson's experiences on The difficulty basically appreared in EDU's Oct 1991 difficulty.