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Michael Mccullough Posted: Sep 09, 2015 02:33 AM	What to do with attic? I recently got into spray foam insulation and have some question. I also do radiant barriers in attics. Main question is would spraying the roofline of an attic or spray the floor of the attic and putting proper venting and a radiant barrier be more effienct. I'm lost on why the roofline gets the foam instead of the ceiling? Also I've heard that there are shingle companies not warranting their product because spray foam heats the shingles. Has anybody had this happen? Last question, I've got a graco fusion air purge gun and was wondering what mixing chamber you guys use with 2.0 closed to get a really nice looking job on foam that will show. Also what mixing chamber for open cell. Thanks.
jimcoler I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs. I've expanded my knowledge into t Posted: Sep 09, 2015 09:33 AM	Hi Michael, I too have jumped on the radiant barrier band wagon only because it works and it makes total sense. The first mode of heat transfer is radiant heat transfer. Only then you get conduction and convection occurring. So, I'm in total agreement with your use of a radiant barrier and allowing the roof to vent where ever possible. I just built a barn and I used Low-E reflective insulation on the underside of the roof, applied another layer of Low-E reflective insulation under the 2x4 top chords of the trusses which leaves about a 3" air space allowing the heated air to escape. The I sprayed 6-8" of open cell to the underside of the Low-E. The place is awesome and it can be heated almost with a candle. I also typically used an AR6060 (#3?) chamber for open or closed cell. Sometimes I dropped down to an AR4949 chamber (#2?). I've sold my business about two years ago but I still read some of the comments on these blogs and I'm still involved! So, keep thinking and you'll find the right answers!
mark moyer Posted: Mar 24, 2016 07:36 PM	i have remove a few radiant blankets in attics the past few years.. real perty install,,darned the do nice work... filterglass under it was soaked.... customer said the blanket made not difference in their energy bill since installed... but that was here,,, 3-4" open cell foam down on attic lid to create the building envelope over the top of the structure. on r15 or so,,so then 15" fiberglass for R60 total system,,,air impermiable foam seal that still allows the designed ventilated structure to do just that,,,transfer moisture laden air up thru the media and hopefully out the ridge vent or vents.... ar6060 works unless we got big vaults,,,may hog a 70 if ambient conditions allow.. jim did you retire or move on to amway? jk :)

Author

Comments

Michael Mccullough

Posted: Sep 09, 2015 02:33 AM

What to do with attic?

I recently got into spray foam insulation and have some question.
I also do radiant barriers in attics. Main question is would spraying the roofline of an attic or spray the floor of the attic and putting proper venting and a radiant barrier be more effienct. I'm lost on why the roofline gets the foam instead of the ceiling? Also I've heard that there are shingle companies not warranting their product because spray foam heats the shingles. Has anybody had this happen? Last question, I've got a graco fusion air purge gun and was wondering what mixing chamber you guys use with 2.0 closed to get a really nice looking job on foam that will show. Also what mixing chamber for open cell. Thanks.

jimcoler

I have over 10 years of experience specifying and installing open and closed cell spray foam. I've sold my business but I'm still selling for the new owners and consulting on large and custom specific jobs.

I've expanded my knowledge into t

Posted: Sep 09, 2015 09:33 AM

Hi Michael,
I too have jumped on the radiant barrier band wagon only because it works and it makes total sense. The first mode of heat transfer is radiant heat transfer. Only then you get conduction and convection occurring. So, I'm in total agreement with your use of a radiant barrier and allowing the roof to vent where ever possible. I just built a barn and I used Low-E reflective insulation on the underside of the roof, applied another layer of Low-E reflective insulation under the 2x4 top chords of the trusses which leaves about a 3" air space allowing the heated air to escape. The I sprayed 6-8" of open cell to the underside of the Low-E. The place is awesome and it can be heated almost with a candle.

I also typically used an AR6060 (#3?) chamber for open or closed cell. Sometimes I dropped down to an AR4949 chamber (#2?). I've sold my business about two years ago but I still read some of the comments on these blogs and I'm still involved! So, keep thinking and you'll find the right answers!

mark moyer

Posted: Mar 24, 2016 07:36 PM

i have remove a few radiant blankets in attics the past few years..
real perty install,,darned the do nice work...
filterglass under it was soaked....
customer said the blanket made not difference in their energy bill since installed...
but that was here,,,
3-4" open cell foam down on attic lid to create the building envelope over the top of the structure.
on r15 or so,,so then 15" fiberglass for R60 total system,,,air impermiable foam seal that still allows the designed ventilated structure to do just that,,,transfer moisture laden air up thru the media and hopefully out the ridge vent or vents....
ar6060 works unless we got big vaults,,,may hog a 70 if ambient conditions allow..

jim did you retire or move on to amway?
jk :)

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