Purchase plastic in dimensions that limit the number of seams between plastic sheets.
Plastic over insulation in garage.
The best vapor barrier to use is roll of plastic sheeting.
If water vapor diffuses or infiltrates into the wall cavity and finds the cool surface moisture problems can occur.
The cool surface is the sheathing assuming no exterior insulation.
The humid air is indoors.
Danny lipford in an uninsulated attic over a garage.
If you are insulating the garage ceiling not only by the truss level but also up by the roofline then you must leave at least 1 1 2 to two inches of air between the fiberglass and the underside.
Equipped with pretty much everything you need you can buy a garage insulation kit at a variety of retailers including home depot lowes or amazon.
Plastic on the outer surface of a wall in cold weather could cause problems.
Best for long unobstructed spaces like over attic joists.
Attics walls and between crawlspace joists.
Stops heat loss into your attic.
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.
Six mil polyethylene plastic comes in rolls of various dimensions.
Your bonus room subfloor usually osb or plywood is a perfectly adequate vapor retarder so no polyethylene is needed even in the 1970s scenario before building science made us smarter.
Stops heat loss into your attic.
Press the poly firmly into.
Most insulation is made of fiberglass and fits into the walls between the studs before drywall is installed.
Featuring fiberglass or polystyrene panels these kits will generally come with enough pre cut panels to cover a garage door with a width of 9 ft.
Must be measured and cut to fit walls or flat surfaces.
Make sure you have enough ventilation on your roof as well.
There should be a continuous ridge and soffit ventilation.
Install the plastic sheeting only after the.
Plastic on the outside.
Glass fibers in puffy strips with or without a paper or aluminum face.
Squirt a bead of acoustical caulk sealant designed for use with a poly vapor barrier along the bottom and top of the wall where the plastic meets the floor or ceiling.