Fiberglass insulation must stay dry to be effective.
Use of plastic wall sheets in cold climates.
For cold temperature applications where heat transfer is a concern it is also important to select a plastic material with.
The humid air is indoors and the dry air is outdoors.
This same process occurs inside the walls of your home.
Cambridge ma 02139 4307 1 617 253 3291.
Mit school of engineering room 1 206 77 massachusetts ave.
Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets.
In cold weather a sheet of poly on the interior side of a wall probably won t cause any problems.
Without a vapor barrier in place condensation inside the walls could ruin the.
By installing a sheet of poly there you cut off that drying mechanism and water that finds its way into walls can stay there longer and do more damage.
This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses.
Condensation occurs whenever warm air meets cold air.
The sheet of poly still cuts off drying to the indoors but it keeps the water vapor in the humid indoor air away from the cold surfaces inside the wall.