A Guide To Installing Fiberglass Batt Insulation

Knoji reviews products and up-and-coming brands we think you'll love. In certain cases, we may receive a commission from brands mentioned in our guides. Learn more.
Fiberglass insulation batting is the least expensive and the easiest to install for the DIY person.

Fiberglass Batting insulation is the most inexpensive and easiest insulation that you can install. Fiberglass Batting comes in two widths designed to fit between studs and joists. Studs and joists are spaced 16 and 24 inches on center. Fiberglass batting comes with or without a facing material. Facings of Kraft Paper, foil-kraft paper, or vinyl are attached to the fiberglass batt during the manufacturing process. The facing act as air and vapor barriers, eliminating the need to install a separate vapor barrier. The attached facing also makes installation easier because of the attached stapling strip along each side of the batting. Some fiberglass batting has distinct fire resistant facings for use in basements and other areas where it will remain exposed. Faced Batts is the way to go unless you are installing new insulation over old insulation, then it's recommended that you install un-faced batting to prevent a moisture buildup between the old and new insulation.

The insulating properties of fiberglass insulation is known as its R-Value. Standard fiberglass batt or blanket insulation has an R-Value of R-2.9 and R-3.8 per inch of thickness. Medium density and high-density fiberglass insulation has an R-Value of R-3.7 and R-4.3 per inch of insulation thickness.

Safety issues when installing fiberglass insulation.

Wearing goggles, a dust mask, a long-sleeved shirt, and heavy work gloves are the orders of the day when working with any type of fiberglass insulation. Fiberglass dust and fibers can damage your eyes and lungs. Fiberglass will also irritate you skin. You can save a considerable deal of money on energy costsand on the cost of having the installation installed by a professional, but doing it yourself could find you in the emergency room if you don't take the proper precautions.

Tools and supplies that you will need.

  • Tape measure
  • Metal straightedge
  • Razor knife
  • 3-inch putty knife
  • Safety goggles
  • Dust masks (buy 2-strap masks with an N-95 Rating)
  • Work gloves
  • Staple gun (manually operated or electric)
  • Fiberglass insulation (Select the proper R-Value insulation for the area you are going to install it)

Fill all the voids between the studs and joists with insulation.

  1. Beginning at the top of the wall, butt the insulation tightly against the wall's top plate.
  2. Push the insulation batt all the way to the back of the wall cavity as you work your way down to the wall's base plate or sill plate. The Batts will fit tightly between the studs.
  3. Using the metal straightedge as a guide, cut the batt off, so it will butt tightly against the wall's sill plate.
  4. After you have all the voids full, pull the Batts out flush with the front edge of the studs and staple the edge tapes to the face of the studs. Compressed insulation loses its R-Value so make sure you use the right thickness for the depth of the wall cavity.

Installing insulation around electrical wires and plumbing pipes.

To install insulation around electrical wiring, electrical boxes, and plumbing, split the insulation Batt, placing half of it behind the cable, box, or pipe and the other half in front of the cable or pipe. In the case of an electrical box, cut the Batt to fit tightly around the box.

Fill the voids around windows and doors.

Stuff the voids around windows and doors with insulation. Use the putty knife to push un-faced Batts into the gaps.

Installing insulation in ceilings.

Follow the same procedure for insulating between floor and ceiling joists.


Jerry Walch
Posted on Nov 11, 2010
Kaleidoscope Acres
Posted on Nov 11, 2010
Posted on Nov 11, 2010