"Darryl" wrote in message
oups.com...
I just realized the bricks in the top layer of my house's block
foundation are not sealed in any way on the top.

Wouldn't that provide an air channel all the way from the bottom of the
wall to the top, open to the inside of the basement?

Isn't that a bad thing, at least from an insulation & radon point of
view? If so, what do I seal them with?

Yes, it will and insulating it will make a difference in your utilities.
There are many types of ill for insulation. Do a Google search for "block
fill" and you will come up with some
http://www.polymaster.com/block-fill.html
http://www.thermalfoams.com/construc...block_fill.htm
http://www.alliedfoamtech.com/Blkfil.htm