Installing Fiberglass Blow In Attic Insulation

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  • 2-5 hours
  • Intermediate
  • 50-200
What You'll Need
Cellulose insulation
Cellulose blower
Tape measure
Metal flashing
Long sleeves
Long pants
Safety Eyeglass
Hat or Cap

Fiberglass blown-in attic insulation is less costly that other types of insulation, but is still very efficient. It can be a bit tricky to install, however, and if you do not use the proper methods of application, the results could turn out to be uneven and fluffy, which will not insulate well.

Improper application can also cause health hazards, including irritations to the skin, eyes, and lungs. For this reason, it is important to remove children and pets from the home while you work. Follow the instructions below for a successful installation.

Step 1 – Determine the Area that Needs Insulation

Before anything else, you need to determine the square footage of your attic ceiling that needs insulation. You can do this by multiplying the length of the attic ceiling by its width.

Step 2 – Cover the Attic Access

To keep fiber off the attic access, cover the access door with cardboard. To do this, measure the size of the attic hatch or door and then cut the cardboard to fit into it. Use adhesive tape to keep the cardboard in place.

Step 3 – Block the Recessed Light Fixtures

If you have recessed light fixtures in your attic, block them using metal flashing. When putting on the metal flashing, be sure to keep at least 3 inches of airspace between the flashing and the light fixture. The metal flashing will keep fiber away from your recessed light fixtures.

Step 4 – Use Rulers to Guide You

To know if you have reached the optimum insulation depth, put some rulers in strategic places. You can use adhesive tape to hold the rulers in place.

Step 5 – Put on Protective Gear

After getting your attic ready, put on your long sleeves, long parts, safety eyeglasses, dust mask, gloves, and hat.

Step 6 – Install the Blown In Fiberglass Insulation

To install your blown-in fiberglass insulation, fill the hopper of the blower with cellulose insulation and then hold the hose parallel to the floor. The insulation should fall 10 to 12 feet away from where you are standing.

When installing the insulation, start at the farthest end of the attic and methodically work towards the center. Check the depth of the insulation from time to time and make sure you do not cover the eave vents. If you accidentally cover the vents, use a putty knife to gently crape off the insulation.

You may need to refill your hopper from time to time, so check its content every few minutes. For best results, do not let the content of your hopper fall below its minimum requirements.

Step 7 – Remove Covers

After applying your insulation, remove the covers on the attic access door and the recessed light fixtures.