Recessed lighting fixtures also have pot or name can lights, as they are in the form of cylinder. The front fits flush with the ceiling, and most of the can lying on the roof or in the attic area. However, a problem with the design is that the holes in them can allow warm, moist air from inside the house to enter the attic. To avoid this, owners must build an insulated box for recessed lighting fixtures.
Use a tape measure and a pencil to draw five boxes in the drywall in the following sizes: A box should be 29 inches long by 21 inches wide. Don disposable latex gloves before proceeding with easier cleaning and a plastic tarp on the work surface spread. Insert panel B and C in the center of the foam on both sides. Never mind that the panel is on which side.
Have the attic insulated box and place it on the recessed lighting fixtures. Trace the outline of the bottom of the box with a piece of chalk and set the box aside. Apply a continuous layer of spray foam along the entire perimeter of the chalk line and place the box in position.