How to Install Fiberglass Batt Insulation

Many homeowners opt for fiberglass batt insulation to enhance energy efficiency in the home. It is one of the cheapest and most effective insulations for residential purposes. Fiberglass batts are panels made from fiberglass wool. They come in various lengths, widths and R-values which refers to the insulation properties of the fiberglass. Batts with an R-value of 30 to 38 are mostly used for ceilings and attics. For interior walls, it is best to use R-11 batts while exterior walls generally require R-13 to R-21 batts. It is a good idea to obtain precut batts that fit on standard 8 feet and 9 feet walls to make installation easier. It is also helps if you purchase batts with a facing. This may consist of vinyl or foil-kraft paper. It acts as a vapor barrier and eliminates the need to install a separate barrier after batt installation. Below is a guide to help you install your fiberglass insulation.

Tools and Materials Needed:

  • Batt insulation
  • Utility knife
  • Sharp blades
  • Putty knife
  • Measuring tape
  • Straight edge
  • Staple gun
  • Dust mask
  • Goggles
  • Gloves
  • Step ladder

Step 1 – Preparation

Fiberglass can cause irritation to the skin. Wear a long sleeved shirt and gloves to protect your hands from possible irritations. You also need to wear a dust mask to prevent inhalation of extremely fine pieces of fiberglass. These can cause respiratory complications if inhaled. Goggles will help keep the fiberglass from your eyes.

Step 2 – Measurements

Use your measuring tape to determine the area from the ceiling to the floor to be fitted with insulation. Add an extra 1/2 inch to the width and length to ensure a snug fit. If you cut the batts to the exact size you’re likely to end up with gaps during installation. This reduces on energy efficiency. Slit open the insulation package and roll out a panel of batt. Transfer the measurements and cut the required size with a utility knife.

Step 3 – Installation

It is best to begin at the top. Climb onto your step ladder and push the insulation right to the back of the wall cavity. Fit the insulation snugly into place between the studs. Do not compress the batts during installation as it reduces energy efficiency. Once you’ve filled all the studs, staple the batts into the studs on both sides at 1 foot intervals. Work steadily until you get to the bottom. Proceed to the next wall section and work in a similar manner until you’ve insulated all the walls.

Step 4 – Electrical Cables and Plumbing Pipes

Hold the batt at the bottom firmly with your hands. Split into 2 at the middle all the way to the top. Position one half behind the cable and place the other half over the cable. Place the insulation firmly into the wall cavity.

Step 5 – Voids around Windows and Doors

Cut out thin strips of batt with your utility knife. Use a putty knife to stuff the batt firmly into spaces around the windows and doors.