Radiant barrier - Direct contact

Guest User
6/18/2008
I just re-roofed my house. Removed shingles from full plywood roof on 5/12 pitch. On the plywood was placed 1x4 stripping leaving 48" spacing in between. In the space was laid 3/4" styrofoam foil backed insulation with the foil facing up. This made the styrofoam flush with the 1x4. On top of this was laid foil/foam/foil, the lastest from prodex so here I have prodex latest product plus 3/4 styrofoam with foil also facing upward. Metal roofing was placed on top of this with no airspace. Metal roof is dark green. In the attic the gables were sprayed with 4" of 1# apex foam. The overhangs on the house was sprayed. Total sealed. No vents anywhere. I put temperature and humidity monitor in attic to record what was suppose to be DRAMATIC reduced attic temperatures. Problem is that with outside ambient temp in the 90's my attic temp is now in the 130's during the day. I am not happy at all going to all this expense to double insulate the roof. Seems the direct contact of the radiant barrier may be the problem. Any suggestions or comments? I am now considering putting some type of vent in the attic ( which I removed when going this so called perfect route ) Was all of that double insulating the roof a total waste? I also sprayed 8" of the apex 1# foam on my attic floor (ceiling topside) so I am still adequately insulated, just disappointed that my attic is getting hot with all the $ spent. To note I also put hard metal ductwork, wrapped the duct in prodex foil/double bubble/foil, then when foaming the attic the crew sprayed 2" of the 1# apex on top of the ductwork encasing the bubble wrap. Also prior to wrapping the ductwork in bubble wrap I glued 1/2" styrofoam strips on the ductwork so the bubble wrap would have the small airspace for additional insulation. This is just to keep the ductwork insulated and 100% sealed and no temperature loss is taking place due to the hotter attic temperature. I am saying all of this so you can grasp the concept that I have went all out to superinsulate my attic and ductwork from every angle but the high temperature is a very big disappointment. All comments are appreciated. Thanks.
Guest User
6/18/2008
I guess one option is going back and sraying 1" of the Apex foam on the bottom side of the roof then it would be the same as a lot of new construction jobs and consider the topside "sandwich" a good lesson for others to learn from my mistake.
Todd Miller
Isaiah Industries, Inc.
6/22/2008
I think you have analyzed your situation correctly and I agree that spraying the underside of the roof deck is the best idea at this point. Radiant barriers do not work in a sandwich and in fact willl conduct heat very well.
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