Air barrier moisture barrier ? Faced vs unfaced insulation ?

Wind82

I recently acquired a four unit apartment building ,the building is built two on top of two units . The lower two units have been gutted due to broken pipe based flooding which lead to black mold . I have reached the stage when it is time to replace all the insulation and drywall in these two units . What i need to know is do i need to place a vapor / air barrier between the two units and or exterior walls ? Do i need to use faced or un-faced insulation ?



Thanks in advance .

Nailbags

This were you need to tell us were your from, it helps a whole lot.
I will give you a few simple answers that may help.

The faced batts are for the exterior walls and the paper goes to the warm side. So if you live in the northern climates the paper faces in. If you live say in south Florida the paper goes to the out side.
for insulation between floors that is the first and second floor no facing is required. Under the home in the crawl space Faced with the paper facing up to the living side i.e the warm side.

I sure hope that helps.
Best of luck with your project

Wind82

I live in Virginia . The building is slab built so there is no crawl space. I plan to house wrap the building as i am re-siding it anyway . If i have to place an air / moister barrier would an rc channel have an effect on it's performance ?

Nailbags

Because you live Virgina I am not sure what your climate is like I would consult the local Building dept. I would not want to give you the wrong information and cause you a problems down the road.

jklingel

I'd bet "probably not" on the vapor barrier, but if you have a lot of humidity, them maybe so; buildingscience.com has maps that indicate whether one is advised or not, and if so, where in the exterior wall. In most places, not. In very cold (N Canada, Interior AK and north), perhaps. In some hot humid places, perhaps. Air seal for sure. As for insulation, get something better than fiberglass batts; they pretty much suck. Roxul is better. Between the floor/ceiling of the apartments, you could insulate for noise reduction using unfaced batts (cotton, cellulose, or wool I believe are more dense than fg and there let less noise through. Besides, they don't put itchy crap in your eyes. Search here for topics on noise reduction.)

Wind82

Sound insulation is not my problem , i have no interest in adding sound proofing as most apt buildings do not have it . Roxul i Cost a lot of money . If i were to do any soundproofing it would be with rc channel not roxul . I appreciate the response and other information included in it .

jklingel

And saves you more money, too.