How To Install Unfaced Insulation On Attic Floor

Don t cut near wiring.

How to install unfaced insulation on attic floor.

Installing insulation has almost the same steps for all. If it is too big then trim it to size. Install batting between the attic s floor joists. The batting material must be faced and at least as thick as the joists are wide so the batting is nearly flush with the top of the joists.

Whether using loose fill or batts put the vapor barrier closest to the warm side of your installation where hot moist air would get in facing the house s interior in cold climates beneath floor insulation and the attic s interior in hot climates on top of floor insulation. Cut the insulation on the unfaced side against a safe backstop such as an unfinished floor or another smooth flat surface. Fiberglass is typically r 3 5 to 3 8 per inch so an attic needs a total of about 10 inches of insulation under floors about. For this reason faced insulation is typically installed on the.

California for instance requires r 38 in attics and r 11 in floors. Measure the roll or batt of insulation to the area that you are going to install it in. Remember to set the paper faced insulation upwards. Attic dek flooring is an easy to install floor option that provides additional storage space supporting up to 250 lbs.

The purpose of insulation facing. You may need to split or cut the insulation to fit it carefully around obstacles such as bracing ducts electrical boxes wiring and pipes. Raise ceiling joists also if the attic insulation is thicker than your ceiling joists you can raise the height of the joists to above the insulation by attaching 2 3 s to their top edge before you attach the attic floor boards. This is the reason you need not add a vapor barrier when you are using paper faced insulation.

The facing on kraft faced insulation is made of kraft paper with an asphalt coating that makes the paper impermeable to water vapor.