Insulation, Radiant and Vapor Barriers - Vaulted Ceiling...Car-Decking with no attic

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Plumb Bob
12-02-06, 10:16 PM
About 500 square feet of my house has a vaulted ceiling. The ceiling consists of 2X6 car decking, which is exposed to the room below, covered with 1/2 inch of high denseity foam that has the foil on the interior side, glued to 1/2 inch mdf to which the asphalt shingles are attached. I probably should have had additional insulation added when I reroofed. I would like to know if there is something I can now do from the inside. I would like to do something like installing some foam board and cover that with wood boards to make it look like what I have now, but I don't want to creat other problems. I live in a northern climate where there is just a little bit of freezing weather. Thanks for any ideas.

Plumb Bob


Energy Auditor
12-03-06, 04:00 AM
Hi Plumb Bob, I am an Energy Auditor but I am not sure what you mean by 2 x 6 car decking. If you would like to send me an e-mail with a picture, I would be happy to review it. You may have options such as dense packed blown in cellulose, which could be done from the inside, but that would depend on how much room remains in the wall cavity. What is the R-value of the high density foam and do you you know the recommended R-value for your area. E-mail info@newenglandenergyaudit.com

resercon
12-03-06, 09:09 AM
http://www.resercon.com/Ventilation.html

The problem with answering your question Plumb Bob has to deal with Ventilation. Your roof is apparently not ventilated and to suggest that you add insulation from the interior of your home would create more problems for you than it would solve. I wrote this article over a decade ago and towards the end of it. it discusses "Cold Roofs".

Energy Auditor, I was one for over 15 years. My website, www.resercon.com is a compilation of many of the issues I had to deal with while in the field. It is explicitly written for the average energy bill payer. You may find it useful when dealing with your clients.