Installing Fiberglass Batt Insulation

Use these tips and techniques to ensure proper installation of fiberglass insulation.



Photo by: Jupiterimages


For homebuilding pros and amateurs alike, installing fiberglass batt insulation probably sounds like a piece of cake (in relation to electrical wiring or plumbing, that is.) However, not taking the application seriously may sabotage the effectiveness of your home's insulation. Installing fiberglass batt insulation requires a very careful approach to ensuring a consistent installation without gaps or compression.

If we think of a home's insulation like a coat in winter, we can see how gaps will sacrifice overall comfort. A hole in your coat where cold air can get in and warm air can get out won't keep you comfortable, just like gaps in insulation will cause a room to be less comfortable. And when we get too cold, most of us will simply crank up the furnace, which uses more energy. The same goes for adjusting the air conditioner in summer. To help keep energy bills in check and be comfortable, it's critical to ensure there aren't any gaps in the insulation.

By paying close attention to just a few techniques, even a beginner can install batt insulation properly. Follow these steps:

  1. Determine the size of batt and R-value needed for the wall.
  2. Cut slits in the batt so that it fits snugly around any obstructions in the wall, like plumbing pipes and electrical wires. When insulation is stuffed into a cavity that has obstructions, gaps are created behind the pipes or wiring and can reduce the R-value of the insulation.
  3. Batt insulation is available unfaced or with a facing already attached. The facing material is generally a vapor retarder that helps resist the movement of moisture vapor to cold surfaces where it can condense. In hot, humid climates (like the Gulf Coast), vapor retarders may not be needed. Check local building practices and/or building codes. If you're using unfaced batts, simply press the batt into the cavity. Make sure that the batt completely fills the cavity but don't shove it in. Compressing fiberblass batts will reduce its R-value.
  4. If you're using faced batts, stable the lip of the flanges to the face of the wall stud every 8 to 12 inches from the top down. Pull the flange down as you do so, to eliminate any gaps. The kraft facing should face the warm side of the wall and should be flush with the stud so that there aren't any penetrations.
  5. Make sure staples are hammered flush with the stud. This will eliminate bumps at the studs and will help ensure the drywall application is smooth.

Next Up

Insulating Attic Access

Learn how to fill up attic spaces effectively.

Installing Spray Foam Insulation to Boost Your Home's Air Quality and Energy Efficiency

Improve your home's energy efficiency with spray foam insulation. Learn about the difference between open-cell and closed-cell, the cost of spray foam insulation and whether it's a good DIY project.

Insulating Beneath the Basement Slab

Keep heat in and keep moisture out with an insulation layer under your home.

Foam Sheathing on Exterior Walls

The best practice for increasing the R-value in exterior walls is to protect them with insulated foam sheathing.

Ladder Framing Allows Better Insulation

Increase space for more insulation by reducing the amount of wood needed.

How to Replace a Window

When it's time to replace an outdated, inefficient window, it can be hard to know where to start, so we’ve got everything you need to know to get the job done.

How to Install French Drains

Divert groundwater from the basement or foundation with the help of gravel and fabric.

How to Install Vinyl Plank Flooring

Many homeowners have turned to vinyl plank flooring as an alternative to hardwood or tile because it’s easy to install, very durable and comes in a huge variety of styles. Learn how to transform your home with high-quality vinyl floors.

2024: Average Cost to Install Carpet Per Square Foot

Knowing the average cost of installing carpet can help you dial in your remodeling budget.

How to Install Wainscoting to a Wall

Add an instant touch of class to a room with these step-by-step instructions on installing beadboard wainscoting.

Go Shopping

Get product recommendations from HGTV editors, plus can’t-miss sales and deals.

Follow Us Everywhere

Join the party! Don't miss HGTV in your favorite social media feeds.