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Posted: Apr 30, 2009 11:04 AM	Heat build up in attic with the Icynene on roof Just this past October I had my 2 story 5 year old colonial roof underside done with Icynene(non vented)and also the basement walls prior to finishing the basement. The rest of the house is fiberglass insulation.I do have the forced hot air and cooling in the attic.I also ran my wood stove that is down in the basement. My first problem was at the begining of the winter. Condensation on the window glass, which led to mold and mildew. Once I kicked up the thermostat, it dried out the air and it seamed to take care of that. By the way even with the temp up my effeciency from the prior year was amazing. The second problem is with our first 85 degree day the temp in the attic shot up past 100 degrees. What gives? I spoke to the Icynene Northeast headquarters and was told that the attic floor should not have the fiberglass insulation there anymore it doesn't allow for the heat to disapate.Why would I want the heat to disapate to the second floor? Didn't make sense to me. I thought you weren't suppose to have heat build up. Another note to mention the house is sided in the Hardie cement boarded. The second floor is just plain old hot. Also we get full constant sun. I am tempted in opening the vents on the gables again and close them in the fall. Any suggestions?
mason Posted: Apr 30, 2009 11:15 AM	Having fiberglass on the floor of the attic and sprayfoam on the underside of the roof deck counters each others insulation efficiency. Take the fiberglass out and the attic will remain cooler and use less energy. Our research tests at ORNL's attic simular suggest the attic space should be within 7-8 degrees of the interior temperature after you take out the fiberglass.
Posted: Apr 30, 2009 11:32 AM	What I neglected to mention is that the humidity level is over 60% up there too, I'm concerned about mold, How will the removal of the insulation help? How about when we start using the A/C? Yes it will help cool the attic but will it help with the humidity or add condensation?
mason Posted: Apr 30, 2009 09:37 PM	By air sealing the building you can start to control your indoor humidity. Excess moisture can be vented out with the right type of HVAC ventilation. I found that when I insulated and air sealed my house with SPF that my humidity ranges reduced from 10 % in the winter and 65% in the summer to 35% in the winter to 55% in the summer. Seal tight, ventilate right.
Posted: May 01, 2009 09:08 AM	I am meeting with my installer today to go over the problems. What concerns me is that he hadn't heard about the insulation on the floor needing to be removed. This is why these forums are a great way to get people educated. I also believe there might be a air leak by one of the dormers,I knew it was going to be a tough spot to do because they had to go behind the hvac unit and some framing.I noticed there was some melting of snow on the roof this past winter. How about doing a pressurized smoke test in the attic. Has it ever been done? I know it is done for other things, Or am I going overboard with the sealing thing.

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Posted: Apr 30, 2009 11:04 AM

Heat build up in attic with the Icynene on roof

Just this past October I had my 2 story 5 year old colonial roof underside done with Icynene(non vented)and also the basement walls prior to finishing the basement. The rest of the house is fiberglass insulation.I do have the forced hot air and cooling in the attic.I also ran my wood stove that is down in the basement. My first problem was at the begining of the winter. Condensation on the window glass, which led to mold and mildew. Once I kicked up the thermostat, it dried out the air and it seamed to take care of that. By the way even with the temp up my effeciency from the prior year was amazing. The second problem is with our first 85 degree day the temp in the attic shot up past 100 degrees. What gives? I spoke to the Icynene Northeast headquarters and was told that the attic floor should not have the fiberglass insulation there anymore it doesn't allow for the heat to disapate.Why would I want the heat to disapate to the second floor? Didn't make sense to me. I thought you weren't suppose to have heat build up. Another note to mention the house is sided in the Hardie cement boarded. The second floor is just plain old hot. Also we get full constant sun. I am tempted in opening the vents on the gables again and close them in the fall. Any suggestions?

mason

Posted: Apr 30, 2009 11:15 AM

Having fiberglass on the floor of the attic and sprayfoam on the underside of the roof deck counters each others insulation efficiency. Take the fiberglass out and the attic will remain cooler and use less energy. Our research tests at ORNL's attic simular suggest the attic space should be within 7-8 degrees of the interior temperature after you take out the fiberglass.

Posted: Apr 30, 2009 11:32 AM

What I neglected to mention is that the humidity level is over 60% up there too, I'm concerned about mold, How will the removal of the insulation help? How about when we start using the A/C? Yes it will help cool the attic but will it help with the humidity or add condensation?

mason

Posted: Apr 30, 2009 09:37 PM

By air sealing the building you can start to control your indoor humidity. Excess moisture can be vented out with the right type of HVAC ventilation. I found that when I insulated and air sealed my house with SPF that my humidity ranges reduced from 10 % in the winter and 65% in the summer to 35% in the winter to 55% in the summer. Seal tight, ventilate right.

Posted: May 01, 2009 09:08 AM

I am meeting with my installer today to go over the problems. What concerns me is that he hadn't heard about the insulation on the floor needing to be removed. This is why these forums are a great way to get people educated. I also believe there might be a air leak by one of the dormers,I knew it was going to be a tough spot to do because they had to go behind the hvac unit and some framing.I noticed there was some melting of snow on the roof this past winter. How about doing a pressurized smoke test in the attic. Has it ever been done? I know it is done for other things, Or am I going overboard with the sealing thing.

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