Replies

1. 
   DaveMason2 | Feb 10, 2004 02:38am | #1

    2X6 is pretty tight for air flow. I guess you could put some 1" baffles up against the plywood and then spray urethane(4") up against that, maybe a ridgevent. That would give you a R-28, maybe.

    Just having 5 1/2" to insulate doesn't give you alot of options. If you use fiberglass it's going to condensate. You could spray foam 5" which should give you a R-35 but no airspace.

    I don't know if this helps you or not. It's just my two cents worth. 

                                                                                                                    Dave

1. 
   roughneck | Feb 10, 2004 07:49pm | #2

   Thanks Dave,  The other option I've considered is to frame out the rafters to a full 12'' with a channel from eave to a ridge vent.  That way I get more R-value and good air flow but the cost I'm looking into.  The spray foam sounds good but I'm skeptical about it with some things I've heard.  Thanks for the 2 cents.

2. 
   Mongo | Feb 10, 2004 09:39pm | #3

   If you haven't already, consider the structural loads, and where they are going to go, from removing the ceiling/ceiling joists, and how that will affect wall spread. You didn't mention how the house is framed, but it's a point that needs to be considered.

   As you mentioned, you may need to add on to the 2-6s for increased depth. You might be able to get enough just by adding 2x4s cross-wise.

   Anyhow's, you might be able to use a derivation of this: http://forums.taunton.com/tp-breaktime/messages?msg=39539.2