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.
Attic insulation layers.
Because of this this method will normally require you to hire a professional.
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.
So with cold weather.
You can achieve better thermal performance in your attic by adding an additional layer of insulation.
Plan to pull up the flooring and layer new insulation on top of the old.
Although installing insulation in an unheated attic is usually a fairly straightforward job a variety of pitfalls await the unwary.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
Blown in insulation consists of bags of fiberglass or cellulose that are chopped up and blown in to the attic or wall from a machine.
Achieving greater r values in exterior walls in exterior walls add insulating sheathing to achieve a greater r value in your wall system.
When it comes to insulating your attic there are really only two types of insulation worth considering fiberglass batts or blown in insulation.
The higher the r value the better the thermal performance of the insulation.