[I-Hate-Hulse]

I've got a double garage that is attached to the neighbor's double garage. However, these are not attached to the house itself. (it's a detached, attached garage...confusing I know)

I'm currently heating and insulating/drywalling my half of the grage structure. Currently both halves of the garage have uninsulated and unfinished exterior walls. However, by code, a finished dividing wall exists between our two halves of the garage. The dividing wall is like 10inches wide, has lots of insulation in it (about 8" of batt) and is sheeted with fire rated drywall on each of our sides of the wall.

Here's the problem - they never vapor barriered the drywall behind my side of the wall. My neighbor has no plans to heat / or finish their half of the garage. My questions are:

1) Do I have to vapor barrier the dividing wall?

- my instinct says yes, other wise there will be leakage to the unfinished side

2) Can I put Vapor Barrier over the existing firerated dywall on the dividing wall (without tearing it out) and resheet over it with a new layer of drywall?

- or will I get some moisture issues in the fire rated drywall layer?


Thanks!