DIYbanter - View Single Post - Adding insulation by foam board to existing house?

Red Green

wrote in
:

I have a vinyle sided house built in 1998. It has 2x4 walls. We put a
plastic vapor barrier on the inside of the walls then filled the space
between the studs with batt insulation. (unfaced). The outer wall is
osb with no house wrap. On top of the osb is vinyle siding.

I have a small corner of my house where a bedroom window that is
broken is. I need to replace the window. That got me wondering, would
it be beneficial to remove the siding in this area, replace the entire
window, then cover the osb with one inch foam insulating board like
you buy at lowes? Then cover with that house wrap material? Then re
install vinyle siding. My thought would be to do this a little at a
time over the summer until each area around the house has the
additional foam board.

Is this worth doing? Will it cause a problem with window/door fit? At
lowes it looked like this reflective board is only r.2. The r value
goes up with a 3/4 inch air gap but I am not sure how this is done. It
jumps to r 6.2 with this gap.

Just trying to make things more comfortable and lower my bills.

Keeping in mind what others have commented, another possibility:

1.5 inches thick - Tyvek Thermawrap R5.0 Insulating Housewrap

http://www.builderonline.com/insulat...wrap-r5-0.aspx