Things You'll Need
4 or 8 mil plastic sheeting
While it's faster to blow into place loose insulation made from cellulose, you can also save the cost of renting equipment and install it by hand. Cellulose insulation is usually made of cotton or recycled paper and treated with a fire retardant, and it doesn't irritate the skin or lungs the way fiberglass insulation does. Because it doesn't come in batts or rolls, you have to install a barrier to hold it in place when you install it in a wall. The barrier also acts as a vapor seal, which is necessary to protect the insulation from condensation from inside the room.
Stretch a 4 or 8 mil plastic sheet over the studs of the wall where you are going to install the insulation and staple it to the bottom plate, which is the horizontal framing member on the bottom of the wall to which the studs are attached. The sheet should be wide enough to completely cover the wall.
Unfold the sheet halfway and pull it upwards to the height of your chest. Staple the back of the sheet to all the studs it covers, driving the staples at 8-inch intervals along each stud from the top staple to the bottom plate. Leave the front part of the sheet hanging down.
Fill the bay between each pair of studs with insulation up to the point where the sheet is stapled. Wearing gloves and a dust mask, remove it from the packaging and drop it in place with your hands. Tap the plastic periodically to dislodge the insulation from wires, pipes and other obstructions.
Lift the front of the plastic sheeting and staple it about one foot from the top plate of the wall, then drive staples at 8-inch intervals along the studs.
Continue filling the bays until the level of the insulation is the same as the level of the sheet. Lift the sheet farther toward the top plate and staple it, leaving a small opening through which you can fill the rest of each bay. When the bays are full, staple the sheeting to the top plate of the wall.
Insulate an attic space by stretching plastic sheeting loosely over the floor joists so that it drops into the bays and covers the ceiling drywall. Drop loose insulation into each bay, either placing it with your hands or pouring it from the bag, filling each bay to the tops of the joists.
If moisture is a problem, you can install stabilized cellulose insulation, but it requires the use of a special blower.
You can buy cellulose insulation that is made entirely from recycled materials.
Allow attic insulation to breathe by leaving the top uncovered. If you cover both the top and bottom with plastic, the insulation will collect moisture from condensation and begin to clump.