"Jetmech" wrote in message
...
I noticed paint bubbling in my kitchen ceiling. I went into the attic
andfound alotof water underneath the tar paper vapour barrier as well
as on top of the tar paper, which must have been soaked trough. The
insulation is opnlywet where it meets the vapourbarrier. What the
hell is going on here. I've about 50 sq feet of dammage plaster
celing.

My understanding is that tar paper is a moisture barrier, not a vapor barrier -
that is, it allows vapor to pass through it. So, the vapor in your house passes
through it, then condenses in the insulation. It is possible a vapor barrier
paint could help.
Otherwise, install a proper vapor barrier in the attic under the insulation, or
install insulation with a built in vapor barrier.