Garage attic insulation

[Schwartzint1]

I have a finished garage. The attic has no existing insulation. I just got a pretty good deal on some un-faced insulation. Is it okay to use this? Again there is nothing in my attic. Just the studs, drywall and can lighting. The attic is well vented and has good air flow.

 

[vekster]

interested in the responses.
I have an attached garage that is sheetrocked and not insulated.
Attic is open to the house so I want to insulate the celing from the attic side.

i was under the impression that I would have to add a vapour barrier between the existing drywall and the added insulation.

 

[stroked89coupe]

Be sure your can light are ic rated for insulation. If not take the appropriate steps when installing the insulation.

 

[BlackTalon]

If you will heat the garage you should have a vapor retarder on the underside (warm side) of the insulation. Otherwise you will get condensation in the insulation and it will lose it's insulating ability which could also cause damage to the wood trusses over time.

 

[cagullett1]

Im confused why you would need a vapor barrier... unfaced and blown in insulation is used all the time in attics, and I've never seen anyone use a vapor barrier before installing.

 

[Banjorear]

Blown in on the ceiling, I think the OP is talking about insulating the rafters. This is where the hot air will eventually go. I think that is why you need the vapor barrier.

 

[Schwartzint1]

Can lights are insulation rated. I got about 450sq ft of R19 unfaced for 50 bucks. Decided to use it for the garage attic space. Hope moisture is not to much of an issue. Here is a cell phone pic about half way through yesterday.

 

[Dick in Wisconsin]

Im confused why you would need a vapor barrier... unfaced and blown in insulation is used all the time in attics, and I've never seen anyone use a vapor barrier before installing.

Trust us. There is a vapor barrier there somewhere!

 

[BlackTalon]

Im confused why you would need a vapor barrier... unfaced and blown in insulation is used all the time in attics, and I've never seen anyone use a vapor barrier before installing.

May not be necessary in North Texas. The requirements vary depending on which 'zone' you are located in (per IRC).

In an area controlled by heating days (i.e., Detroit) , it would be short-sighted to not have a VR on the warm side of the attic insulation.

 

[Highbeam]

Vapor barrier can be the paint on the drywall.

 

[cagullett1]

Trust us. There is a vapor barrier there somewhere!

May not be necessary in North Texas. The requirements vary depending on which 'zone' you are located in (per IRC).

In an area controlled by heating days (i.e., Detroit) , it would be short-sighted to not have a VR on the warm side of the attic insulation.

That's a good point. My house is only a year old (we are the original owners), and I watched the build go up. I've also added outlets and have had to run wire through the attic, causing some of the insulation to be moved around a little bit. There is definitely not anything between the blown in and the drywall. This is interesting, and it makes me question whether it's a necessity around here like it is up north.

 

[BlackTalon]

I'm not sure where you are exactly in North Texas, but the IRC shows portions of the northern part in climate zones 2, 3 and 4. They only require vapor retarders in zones 5, 6, 7, 8 and Marine 4. So it looks like you are in a part of the country where VRs are not typically needed.