attic insulation / knee wall

oscarMadison · 01-19-2010, 08:50 PM

Okay, the pics are part of a finished attic, behind the knee wall. Looking for suggestions on what I should do to insulate it. I am not seeing moisture issues. The cellulose is only about 5 inches. The silver you see is fiberglass in bags, silver on one side, brown paper on the other side, R11. The top and bottom show the side wall does not have insulation, is there a reason for this? The knee walls do not have any insulation. The duct work, for a second furnace, is only insulated about half the distance with fiberglass and plastic wrap.

Current thoughts, first looking for leaks, put in durovent attic vents, insulation over that. Was thinking about adding some insulation to the knee walls. For the duct work seal joints then wrap with insulation the foil/fiberglass stuff they sell. I've read some of the other threads, I'm looking more for any spoilers or oddities that you guys might see.

stubborn1 · 01-19-2010, 09:06 PM

The knee walls should be insulated. I have a similar condition in my attic, and I installed r-13 between the studs plus nailed 1" thick rigid insulation to the back of the studs to get the equivalent of R-19 in the walls.

It seems like the insulation in the rafters and ceiling joists could be redundant, but it's not clear from the pictures. Either way, it's probably not enough for your area. Typically, you either insulate the ceiling joists space and leave the rafters/roof framing exposed, or you insulate the rafters and leave the ceiling framing open. See the link on the following site for an idea of what I'm talking about:
http://www.energysavers.gov/your_hom.../mytopic=11420

oscarMadison · 01-19-2010, 09:37 PM

Yeah that's what I thinking for the knee walls fiberglass and rigid board if they needed it. Rigid board to add extra insulation to both bay and stud.

I thought the insulation in both the joists and ceilings might be redundant but wasn't sure. I love the energysavers sight