On Mon, 11 Apr 2005 14:08:27 -0400, "bob smith" wrote:

Hi all,

I'm getting really to insulate and drywall a portion of my basement in an
older (1950's) house. The basement foundation is cinder block, that looks
like it has been covered with some kind of a tar-like sealer, and then
plastered.

I have been monitoring the walls for the last 8 months and there are no
water issues. I do however have some moderate efflorescence on one of the
four walls. This wall is adjacent to the driveway beside my house. Some of
the driveway stones do need to be reseated to properly grade away from the
house, and this is on my list of stuff to do this summer. That should reduce
the efflorescence but probably not eliminate it.

Because I dont have access to the raw foundation wall, a sealer like Drylok
is not really an option. Nevertheless, I plan to coat the surface
with an efflorescence-fighting coating anyways. Of course, these kinds of
treatments only work for a limited time (5 years).

Anyways, bottom line - can I proceed with insulating over this? I was
thinking of using a closed cell spray foam insulation. Would that be
recommended for this situation?

Thanks!

When you insulate the efflorescence wall, you are going to grow some
super mold that may or may not be deadly. Currently, you are drying
off the surface by exposing it and preventing the growth of mold.

My solution would be to place a mesh over the wall prior to applying
the insulation and then permit the top and bottom of the mesh to be
exposed to the room so that air would flow thru the mesh. This
procedure is used in many foam foundation product installations to
prevent mold/moisture.