If your garage is 45 degrees and you have a bonus room heated to 72 degrees above the garage the vapor retarder faces the upstairs room.
Do you need a vapor barrier in the garage attic.
Whether or not you need a vapor retarder hinges on three main factors.
Attic vapor barrier detail for cold climates the best approach for a vented attic in a cold climate is installing a layer of drywall with a good coat of latex paint the paint creates a semi permeable vapor barrier.
Between the two air leakage moves far more moisture than vapor diffusion.
Measure the entire area and write down the results.
Do not overlook attic access door.
Hence the need to reduce moisture flow into the attic and the need for a vapor barrier.
A lot of people think you need a vapor barrier or class i vapor retarder and that it needs to be on the inside of the house in cold climates and outside in hot humid climates.
The classic answer is that the vapor barrier goes on the warm in winter side of the assembly.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
Do not add a vapor barrier on top of the insulation in your attic since the paper facing on the existing insulation is the vapor barrier.
Take a note of the construction of the attic and figure out which type of barrier will be suitable.
Not every wall does.
Take the measurements with you when purchasing materials.
There s one other important qualification.
Vapor moves in two ways by diffusion through materials and by air leakage through gaps and holes in building assemblies.
In cold climates a vapor barrier is almost always needed.
The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.
To install an efficient vapor barrier you need the dimensions of the room.
To be able to answer this question correctly for your home there are a few factors you need to consider before any major attic insulation project.
We put the vapor retarder on the side appropriate for the season the house will be finished and then.
You don t mention whether there is a bonus room or living space above the garage.
The facing on faced insulation acts as a vapor retarder.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
If you are planning to have an attic insulation project for your home you may be wondering whether it is important to have a vapor barrier installed as well.
Here in the mixed humid climate i m in we build rotatable walls.