On Thu, 1 Nov 2007 19:43:24 -0700, "Bob F"
wrote:
wrote in message
...
I want to upgrade my attic insulation. I have 2x6 beams and old
unfaced R13-R19 fiberglass batts up there. I want to add R38 on top of
the existing insulation. I am in San Jose, CA.
[cut]
I went for the batts. It is great to be able to move them aside to add a wire or
whatever. I did it myself. It probably took 3-4 hours.

As far as insulation value, if you place them carefully together, fiberglass
should be fine. And it doesn't settle over time like the blown in cellulose I
put in my previous house.

Why aren't you considering icynene or polyurethane for maximum
insulation?