Blown In Attic Insulation Without Vapor Barrier

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.

Blown in attic insulation without vapor barrier.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. Install siding over the insulation. Handy homeowners can install blown in insulation in the attic. 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.

Attach 1 inch foam board insulation. If you do there is a chance that moisture that has slipped by the first vapor barrier will become trapped by the second vapor barrier decreasing the value of your insulation. On the other hand an air barrier a properly detailed air tight drywall ceiling for example in the absence of a vapor barrier can be effective since it stops the flow of vapor laden air. Apply a house wrap vapor barrier to exterior walls.

They come with or without a paper or foil facing that acts as a vapor barrier. Caulk window trim and use weatherstripping to reduce air leaks. Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical. The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.

A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective. 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. I install my vapor barrier in the middle of the wall system between the two walls. 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.

If you ve tried everything else and are determined to insulate the walls of an old house follow these. Not every wall does. Replace old windows with energy efficient units. When adding additional insulation to an attic that is already insulated never use insulation with a vapor barrier.