When installing insulation in the attic, the general rule is to place the insulation with the paper or vapor barrier facing down, towards the house or living space. This is often referred to as the "warm side" of the insulation.
The primary purpose of the vapor barrier is to prevent moisture from moving from the warmer living space into the colder attic area. If moisture were to pass through the insulation and reach the colder attic, it could lead to condensation and potentially cause issues such as mold growth or damage to the structure.
By placing the vapor barrier facing down, any moisture that might get into the insulation will be blocked from entering the attic space. The insulation will help maintain a more consistent temperature in your living space, keeping it warmer during colder months and cooler during warmer months.
Keep in mind that there are different types of insulation materials, and some may not have a vapor barrier. In such cases, the insulation should still be placed with the primary insulating layer facing down.
If you're unsure about the proper installation of insulation in your specific attic, it's always a good idea to consult with a professional or follow the manufacturer's guidelines for the insulation material you are using. Proper insulation installation is crucial for energy efficiency and maintaining a comfortable home environment.