I should finally start my 2nd floor addition this summer (after a long pause due to financing issues). I’m leaning towards using an I-Joist flooring deck and SIPs for the walls. The first floor walls consist of 2 x 4 studs, with retrofitted cellulose blown-in insulation (I always had my doubts as to whether all the cavities where filled), 1 x 6 sheathing boards, felt wrap, and vinyl siding. I plan to finish the entire house in stucco.
My goal is to try to balance the 1st floors energy efficiency with that of the second floor (SIP). How do you suggest I go about it? At the least, I plan to install house wrap. I guess I should also add foam boards (any suggestions?). However, what about the 1 x 6 exterior wall boards. Does it make sense to replace them with 4 x 8 sheeting? If so, what type?
Thnx.
Replies
If you're going to install housewrap, and there's no need for additional bracing of the framing, and the existing sheathing is in good condition (and not so brittle that it will shatter when nailed), there's no need to replace it.
Thnx for your response Dan. From what I remember, when they removed some of the siding in order to bore holes in the sheathing for the insulation, the wall boards seemed to be in decent condition (maybe a few will need replacing). However, I'm concerned about the space between the boards (I don't thing they're tongue and groove). Also, the insulation guys did not plug the holes they made to blow in the insulation (they said it wasn't necessary). From what I understand, insulation needs a barrier. Will the house wrap be sufficient?
Edited 5/2/2009 7:27 pm ET by djthx
You might want to plug the holes, just to keep insulation from "leaking" out. There are plugs specifically made for this, or you can just staple a piece of tin or stiff plastic (scraps of vinyl siding, eg) over the holes.The housewrap will cover the problem of the gaps between the boards.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith