How To Install Unfaced Insulation On Attic Floor

Measure the roll or batt of insulation to the area that you are going to install it in.

How to install unfaced insulation on attic floor.

California for instance requires r 38 in attics and r 11 in floors. 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. Remember to set the paper faced insulation upwards. This is the reason you need not add a vapor barrier when you are using paper faced insulation.

For this reason faced insulation is typically installed on the. Install batting between the attic s floor joists. Cut the insulation on the unfaced side against a safe backstop such as an unfinished floor or another smooth flat surface. If it is too big then trim it to size.

Now here s a situation where a homeowner what looks like many years ago added insulation they added a three inch layer but it has facing on it and that could create a. 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. I ve always said adding insulation to your attic is some of the best money you can spend to make your house more energy efficient but whether to use faced or unfaced insulation is a great question. You may need to split or cut the insulation to fit it carefully around obstacles such as bracing ducts electrical boxes wiring and pipes.

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. Don t cut near wiring. The purpose of insulation facing. Installing insulation has almost the same steps for all.

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