Stops heat loss into your attic.
Plastic over insulation in garage.
There should be a continuous ridge and soffit ventilation.
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.
Press the poly firmly into.
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.
After the insulation is installed it is necessary to cover it up with a vapor barrier so the glass fibers are not inhaled.
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 outside.
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.
Stops heat loss into your attic.
Purchase plastic in dimensions that limit the number of seams between plastic sheets.
Plastic on the outer surface of a wall in cold weather could cause problems.
If water vapor diffuses or infiltrates into the wall cavity and finds the cool surface moisture problems can occur.
Wall insulation keeps out cold.
Danny lipford in an uninsulated attic over a garage.
Six mil polyethylene plastic comes in rolls of various dimensions.
Must be measured and cut to fit walls or flat surfaces.
The cool surface is the sheathing assuming no exterior insulation.
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.
Attics walls and between crawlspace joists.
The humid air is indoors.
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.
Most insulation is made of fiberglass and fits into the walls between the studs before drywall is installed.
Glass fibers in puffy strips with or without a paper or aluminum face.
Install the plastic sheeting only after the.
Insulating the area in the attic over a garage might keep the temperature a little more stable in the garage but it does little to reduce the amount of energy needed to heat and cool your house so it s not a good investment of your energy dollars.