"SofaKing" wrote in message news:rn5%b.614683$X%5.590399@pd7tw2no...
Yes. My floor joists are indeed set into the concrete. Hmm.

Moisture can wick into the concrete from either the ground, or from
brick sheathing-if there is no flashing.

Apparently, the problem is that insulation in the rimjoist area
reduces airflow that would dry out any moisture that might get into
this area, and of course, untreated wood doesn't get along well with
concrete plus moisture.

NRC recommends that you caulk the area well with accoustical sealant
to eliminate airflow (that will provide significant energy efficiency
improvement). You will find detailed instructions on pages 65, 71, 74
(see last thread)dealing with joists-in-concrete.

The recommendation is to caulk the seam at the top of the header
(between header and subfloor), and at the bottom of the header
(between header and concrete foundation); then caulk the seam where
the floor joist meets the header, and around the joist where it is
imbedded in the concrete--whew!

Mr Fixit eh