Replies

1. 
   Guest_ | Sep 21, 1999 05:17am | #1

   *
   I looked at it recently. R-value per inch is similar to fg and cel. But oof! the price is prohibitive. Our inspector's office has approved ventless installations with icynene, but as he put it, "It's a last resort." That is, it's for when you have a roof that's too complex or otherwise murder to vent.

   I've considered a skim layer of it to satisfy the inspector, but only because I'm doing a cathedral-ish ceiling. If I had a big empty truss space I'd choose airtight construction and 500 lbs. of cels in a second.

1. 
   Guest_ | Sep 21, 1999 03:30pm | #2

   *Just curious - why would using Icynene insulation eliminate the need for venting ?

1. 
   Guest_ | Sep 21, 1999 08:08pm | #3

   *Per the manufacturer...Icynene prevents air movement and thus eliminates the need for ventilation (for catherdral installations). There are discussions on many homepages - such as http://members.aol.com/AESinCT/index.htm#Home. Icynene had a page (I couldn't find it - I wonder if that is a bad sign?) with lots of technical discussions.Also read lots of articles about the old myth that roof temps. were higher without venting, and thus the roofing materials would deteriorate faster than roof without venting. This has been shown to not really be a factor... It all comes down to moisture in the roof system, and the long term effects (like rot, mildew, etc....)

1. 
   Guest_ | Sep 22, 1999 04:00am | #4

   *OK, so what is "Icynene"? Is it a trade name? What is it made out of?And, I think "cels" is cellulouse fiber, right?All you trade guys talk shop and its hard for me to keep up!

1. 
   Guest_ | Sep 22, 1999 07:30am | #5

   *Norm - that is why they invented search engines - type in the term and you, too, can be an instant expert (just like me...)"Icynene is a plastic insulation material similar in chemical composition to the material used in pillows and matresses." John - I found a page with some technical discussion at:http://www.icynene.on.ca/professionals/comparegeneric.htmlfrom the main page at:http://www.icynene.on.ca/main.html

2. 
   Guest_ | Sep 22, 1999 07:37am | #6

   *John, have you eliminated PUR foam as an alternative to theicynene? I've seen the urethane foam used in a rehab, and it worked wonderously.Andrew, I heard the R-value to be almost 2x FG per inch of application.

3. 
   Guest_ | Sep 22, 1999 08:27am | #7

   *Nope, although PUR is about 2x (and more so if convection is an issue). I just double-checked at the mfr site given above -- Icynene is R 3.6 per inch. Icynene's big selling point is air-sealing, and the consequent soundproofing.

4. 
   Guest_ | Sep 22, 1999 05:09pm | #8

   *Andrew,Do you think that Icynene is any more air-sealing than PUR? So far, the only place that I find Icynene to be best is in an enclosed cavity, and DP Cels may be just as good there.Ron

5. 
   Guest_ | Sep 22, 1999 09:06pm | #9

   *Is there any chemical issue with Foam-in-place products?I remember a lot of talk about bad urea aldehydes out-gassing from some insulation products about 10 years ago making home owners sick.How do PUR and Icynene avoid this?Icynene sounds alot like isocyanurates, which will kill you.I am pretty tolerant of building-type chemicals, but I do know people who are bothered by new carpets, etc. I like the idea of cellulouse because it seems to avoid that.

6. 
   Guest_ | Sep 22, 1999 10:01pm | #10

   *My experience with Icynene is it is nasty for about a day and then very healthy after that. PUR?....I don't know.

7. 
   Guest_ | Sep 22, 1999 10:21pm | #11

   *I talked for a long time with the local Icy rep. PUR and Icy are probably about the same for air sealing ... Icy claims it allows some small amount of moisture through (16 perm) which might be good for drying. Offgassing on both, I don't know, but they're better than the ureas. They don't use CFC's to blow the PUR anymore, rather some petroleum gas? Neither has formaldehyde, which I'm fairly certain fg uses as a part of its binder.PUR will burn, but won't sustain a flame. When it turns it does release toxic gas. I don't know how this plays out safety-wise. Can't find burning characteristics of Icynene on their site. Here's Icynene's comparison chart. Can't vouch for its accuracy!They claim you can use Icynene in retrofit (enclosed wall) applications, but I'd choose dense cellulose for that. In a large attic, cellulose is again very cost-effective. With a cathedral ceiling, Icynene doesn't really deal with the difficulty of getting enough R-value.

8. 
   Guest_ | Sep 23, 1999 04:37am | #12

   *The September 1999 issue of Popular Mechanics has a 5 page article for homeowners describing various insulation materials. Seems pretty well done (particularly for a magazine that seems to be primarily fascinated with Roswell and various Skunk Works airplanes...). It describes Icynene as "applied like polyurethane but water is used as a propellant. Icynene remains soft and pillowy when set, which means it can expand and contract with the structure. It's been thoroughly tested, and emits no detectable vapors after 30 days..." (p. 95) It gives an insulation cost table comparing 13 types of insulation installations. Their cost comparison chart for installed insulation in their "existing wall retrofit" of 1000 sq.ft. is $1450 for polyurethane spray foam, $1200 for Icynene spray foam, and $700 for blown dry cels. (For r-values per inch, they rate the polyurethane at R-24.8 while the Icynene rates 13 and the cels 14.) However, prices may vary...The recent "This Old House" that they call their "reference edition" (and over price it accordingly) also has a couple of pages on insulation retrofits, but I don't think it is as informative as the PM article - even though the TOH article does contain a one setence quote from one GeneL...

9. 
   Guest_ | Sep 23, 1999 05:12pm | #13

   *It looks like (from Icynene's chart) that closed cavity injectability and shrinkage are the main differances between Icynene and PUR. I didn't know that PUR shrunk. Any body have first hand experience?