In most climates it needs a vapor barrier.
Proper insulation installation in attic.
Begin at a wall and work toward the center of the attic floor or the entryway carefully placing insulation between joists and ensuring a snug fit.
On average an attic insulation project costs between 1 50 and 3 50 per square foot.
Ensure ends of insulation are butted together and flush to underside of framing.
But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.
Diy home repairs are becoming more popular but this is one job you should leave to the professionals.
Place the insulation with the facing side down on a piece of scrap plywood.
Because the simplest and cheapest way to insulate an attic is to add material to the floor.
Like other batt type insulation fiberglass has a predictable r value if not compressed but is difficult to fit around obstacles without leaving gaps.
The basic installation steps are the same for walls ceilings floors and roofs in wood frame houses.
Cut the insulation roll or batt to fit the length of the framing cavity if necessary.
Friction fit insulation snugly between and parallel to all standard and narrow attic framing members.
Or pour fill insulation into such areas.
Recommended insulation levels for retrofitting existing wood framed buildings.
Or fold it back and up between the rafters.
Fiberglass batts the insulation found in most houses in the u s are inexpensive and quick to install.
You only want one vapor barrier in your attic and it should be as close to the ceiling as possible to prevent warm moist air from coming up from the heated house and condensing when it hits the cold air in the attic.
Existing 3 4 inches of insulation.
Add insulation to attic.
The paper facing on insulation has an asphalt layer which acts as a vapor barrier.
Measure between joists if insulating a floor or attic or studs if insulating unfinished walls to find the correct width for the insulation.
To install insulation batts and blankets.
If you re insulating framed walls make sure the insulation is the correct thickness for your wall studs.
Use our roll insulation calculator to estimate how much roll or batt insulation you ll need.
Set a t square or metal straightedge over the insulation and press it down firmly.
Don t push batt or blanket insulation past the top plate at the end of joist runs.
If using insulation with a vapor retardant facing install the material with the vapor retardant side down.
Ensure insulation extends to the outside edge of the exterior top plates and is flush against any ventilation dams baffles.