Faced or unfaced insulation?

[fifth]

About ready to insulate my garage walls in Phoenix, AZ. Is faced insulation recommended? Garage will have heat and A/C. I can purchase unfaced for about $120 less from a vender.

 

[KANSASBOY]

Faced. Faced.Exterior walls need a vapor barrier to prevent moisture from moving from a heated space (inside your home) to a colder space (outside your home).

 

[tfinniii]

Something over the insulation to prevent air infiltration,painted and caulked wall board choice will suffice in your area.

 

[Rbreddin]

Faced. Faced.Exterior walls need a vapor barrier to prevent moisture from moving from a heated space (inside your home) to a colder space (outside your home).

how can you honestly answer that question without first asking anything about how his garage is constructed (or how it's going to be used)..

if he's got a building wrap on it, unfaced is a perfectly legitimate option.
same if he used any kind of building paper or built the exterior out of EIFS or Stucco.

similarly, if he's going to have the OH door open for more than an hour every day then it doesn't matter WHAT kind of vapor barrier he's using around the perimeter of the building.

not only that, vapor transmittance is MUCH less an issue in AZ than it is in other states (like KANSAS, for instance)..

 

[fifth]

Building is stucco, wrapped in black paper material. Dont use the heat much at durning the winter.. 14'x14' overhead door won't be open while AC/heat is being used.

 

[Falcon67]

I used faced, facing inside not out.

 

[n20junkie]

Faced, simply because it resists sagging to the bottom of the stud cavities.

 

[bczygan]

I use faced to keep the batt properly in place, then slash the facing to destroy it's already poor moisture barrier. Then I cover it with Visqueen properly taped and sealed.

Bill

 

[Gerald O]

Depends on climate zone as to whether you need it. In climates where the heating season is longer than the cooling season you generally want the vapor barrier inside. This keeps moist indoor air from condensing on the inside of the cold outside wall. In climates where you predominantly are cooling the house it is the opposite. You rely on the exterior vapor barrier to prevent warm, moist outside air from getting into the wall and condensing on the cooled interior wall surface.

In most cases you do not want a 'double' vapor barrier -- both sides of the insulation, because water vapor will always get in regardless, and then it gets trapped inside. The insulation can get wet and never dry out. It is better to have a drying path.

All that said, kraft faced is not a vapor barrier, it is a vapor 'retarder'. So you're probably ok with it in most climates. It does make some aspects of installation easier (provides support), while it also makes installation more difficult in some ways (needs to be cut and fitted).

Cost can go either way. In my area the kraft faced is stocked more commonly than unfaced, and is actually cheaper than unfaced, which has to be special ordered in some sizes.

 

[southpier]

Depends on climate zone as to whether you need it. In climates where the heating season is longer than the cooling season you generally want the vapor barrier inside. This keeps moist indoor air from condensing on the inside of the cold outside wall. In climates where you predominantly are cooling the house it is the opposite. You rely on the exterior vapor barrier to prevent warm, moist outside air from getting into the wall and condensing on the cooled interior wall surface.

In most cases you do not want a 'double' vapor barrier -- both sides of the insulation, because water vapor will always get in regardless, and then it gets trapped inside. The insulation can get wet and never dry out. It is better to have a drying path.

All that said, kraft faced is not a vapor barrier, it is a vapor 'retarder'. So you're probably ok with it in most climates. It does make some aspects of installation easier (provides support), while it also makes installation more difficult in some ways (needs to be cut and fitted).

Cost can go either way. In my area the kraft faced is stocked more commonly than unfaced, and is actually cheaper than unfaced, which has to be special ordered in some sizes.

this

 

[Dragfluid]

Dense pack cellulose, and you won't need a vapor barrier.