Basement insulation

Tom
I have bare concrete walls right now so I would most likely go with 4 by 8
sheets of foam board.
Is moisture a problem if you use the foil covered foam 4 by 8 sheets? Also
what is recommended to seal the joints between the sheets?
I have been looking at putting additional insulation into my attic (it is
R-38 blown fiber glass). There is a lot of discussion of fiber glass vs
cellulose and cellulose on top of fiber glass to prevent loss of R-value
in the fiber glass. It is difficult to sort out the hype vs. facts on this
debate. What are your thoughts on this?
I do it myself with cellulose an additional R-76 for $1,100 vs. $550 for
just doubling it with another R-38. What is the typical percentage of heat
lost through the roof? and would it be worthwhile to go the extra to add
another R-76 for a total of R-114?
Thanks again
Rob

Hi Rob,
Foil faced insulation is fine. Caulk the joints after you install the foam.
I think a layer of cellulose is a good adjunct to a fiberglass insulated
attic.
The cellulose fibers are smaller and are blown in, so they cover the entire
attic thoroughly. It is a tighter job than fiberglass.
Wow, you are talking my kind of insulation values!
I think if you go up to R-74, you are in great shape. There will be very
minimal heat loss through this attic--as long as the attic hatch is sealed
well and all penetrations are also sealed.
Attic heat loss in a "typical" home at R-38 is usually about 15% of the
total heat loss.
All you energy auditors out there, please pardon this broad generalization.
Tom