Do You Need A Vapor Barrier In The Garage Attic

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.

Do you need a vapor barrier in the garage attic.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. 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. In cold climates a vapor barrier is almost always needed. The classic answer is that the vapor barrier goes on the warm in winter side of the assembly.

Hence the need to reduce moisture flow into the attic and the need for a vapor barrier. In mixed climate areas the vapor barrier is optional depending on the total design of a building. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Not every wall does.

We put the vapor retarder on the side appropriate for the season the house will be finished and then. Take a note of the construction of the attic and figure out which type of barrier will be suitable. There s one other important qualification. Measure the entire area and write down the results.

To install an efficient vapor barrier you need the dimensions of the room. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. Whether or not you need a vapor retarder hinges on three main factors.

You don t mention whether there is a bonus room or living space above the garage. If you need a vapor barrier and your insulation is unfaced you must cover it with a polyethylene film. The facing on faced insulation acts as a vapor retarder. 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.

Vapour barrier is on the top of the rafter then insul then board if heating garage insul vapour then board need hatch for summer to let out hot air i m a insulator typar is a better product in a. Here in the mixed humid climate i m in we build rotatable walls. Do not overlook attic access door. Vapor moves in two ways by diffusion through materials and by air leakage through gaps and holes in building assemblies.

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. 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.