You have several options when insulating your attic. You can place the insulation on the attic floor only which is your typical
vented attic design. Another option is to place all the insulation on the underside of your roof deck and gable walls. In this case
you would not have insulation on your attic floor and you would close up all your attic vents. You would not want to have any vents
to the outside or that would be similar to keeping your windows open all the time. Your attic space would now be part of your
conditioned space. Those are your most common methods but not all of them. Take a look at some of the other FAQs on this site for
more information on unvented attics.
Feel free to click on the "Contact the FAQ Administrator" link to ask me a follow-up question.
Jason M. Hoerter, P.E.
Sr. Product Manager
Copyright © 2011 NCFI Polyurethanes