When adding additional insulation to an attic that is already insulated never use insulation with a vapor barrier.
Blown in attic insulation without vapor barrier.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
Replace old windows with energy efficient units.
I install my vapor barrier in the middle of the wall system between the two walls.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
This flexible insulation material is most often packaged in rolls that come in various thicknesses and standard widths usually 16 inches and 24 inches to fit between joists or studs in a house s framing.
Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical.
Thousands of houses have had insulation blown in without incident mostly because old houses are so leaky that there is little or no chance for water vapor to build up to cause the insulation to.
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.
They come with or without a paper or foil facing that acts as a vapor barrier.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
If you ve tried everything else and are determined to insulate the walls of an old house follow these.
Caulk window trim and use weatherstripping to reduce air leaks.
Not every wall does.
Such a location works both as a vapor barrier as well as an air barrier and eliminates the need for an external air barrier not a easy application on a multi storried building as well as any special electrical pans and their sealing.
Apply a house wrap vapor barrier to exterior walls.
A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective.
Install siding over the insulation.
Handy homeowners can install blown in insulation in the attic.
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.
The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.