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Insulation for ceiling of finished attic

We have gotten two very different opinions on the proper way to insulate the ceiling of an attic we are finishing.  The space will be a bonus room.  Should the Ceiling of the finished attic be insulated or just the knee wall? 
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Posted 2016-02-10T20:43:01+0000  by TVChris TVChris

Hello TVChris, and welcome to the community!

If you are only using the space for the storage, then only insulate up to the knee wall, IF want to use the area as a living space, then insulate the roof/ceiling.  If you are converting the attic area into a living space, there are strict regulations on the amount of insulation required. Rafter depth is an issue, as there is often not enough depth to fit the required insulation — you may need to increase the depth of rafters by adding wood to their undersides.


Posted 2016-02-11T14:36:04+0000  by Angelo_HD_CHI

Hello TVChris and welcome to the Community.


Angelo makes a good point about the rafter space needed for the insulation especially because of the need for ventilation.


Both the ceiling and the knee walls should be insulated in your finished attic space, but proper ventilation must be maintained.



Make sure all gaps between the wall and floor and around pipes and utilities are filled with caulk or foam insulation.


The use of attic ventilation channels (baffles) should be installed before the insulation.  Click on these orange words to see some of baffle available at Home Depot like the Owens Corning Raft-R-Mate.  



Once the baffles are installed you are ready to install the insulation, then drywall.


Thanks for your inquiry.



Posted 2016-02-11T15:16:06+0000  by Char_HD_CHI
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