How to Properly Insulate an Attic in 4 Easy Steps

Properly insulating your attic is essential for running an energy-efficient home. If your attic isn’t insulated properly, chances are:

  • You’re experiencing cold spots in certain areas of your home
  • You’re seeing a buildup of ice dams on your roof and in your gutters
  • You’re missing out on hundreds of dollars in annual savings on your energy bill

If you’re looking to address any of these issues, the secret is to combine traditional insulation with a radiant barrier. Installing a radiant barrier on top of your traditional insulation will provide your attic with an effective 1-2 punch that keeps your home cooler in the summer and warmer in the winter, all while saving money on energy bills. Insulating your attic do-it-yourselfers are out there but many turn to trusted professionals such as


Plus, many utility companies will even offer rebates for installing radiant barrier, which may offset your install costs altogether and save you money on energy bills.

Step 1: Assess the status of your attic insulation

Take a peek in your attic to see if it is already partially insulated. If it is, you’ll most likely see spray foam insulation or the more traditional “fluffy” fiberglass insulation.

If your attic has no insulation whatsoever, it’s time to get to work. Before you start, you need to ask yourself two questions:

1. What R-value does my first layer of insulation need? This question is relatively easy to answer because your local building codes require a certain R-value for attics. It is important to ensure you are aware of all current codes for your area.

2. What type of insulation am I going to use? The second question is a matter of choice. There are two types of traditional insulation you can use:

  • Loose Fill Insulation is the most common type because it is less expensive, faster to install, and provides better coverage than batt insulation. Loose fill insulation is usually blown or poured in, and it is best to hire a professional contractor for this.
  • Batt Insulation is much easier to install and requires no special training to know how to install insulation in the attic.

Step 2: If necessary, install your first layer of attic insulation

Before starting your insulation project, ensure you are wearing the proper safety equipment, especially when working with fiberglass insulation. Fiberglass insulation, also known as glass wool, is composed of tiny glass fibers that can irritate your skin, eyes, and lungs. Always wear gloves, long sleeves, safety glasses, and a dust mask to avoid potential health hazards. Alternatively, you can hire a professional to install your insulation. Additionally, create a walkway and workspace with boards to avoid stepping on and falling through the ceiling. It’s also a good idea to consult an electrician beforehand to eliminate any electrical hazards.

Step 3: Install the radiant barrier foil on top of your first layer of insulation

Once your insulation is in place, it’s time to install your radiant barrier. When installing a radiant barrier in your attic, make sure to use perforated products that allow condensation to pass through, preventing mold and mildew buildup in your first layer of insulation. Due to the “breathability” of perforated products, we do not recommend using tape to seal the seams, as it could trap moisture and lead to mold or mildew.

Radiant barriers can be installed directly on top of your first layer of insulation (on the floor of your attic) or on the rafters (the ceiling of your attic). In some cases, installing the radiant barrier in both locations is beneficial.

Installing radiant barrier in warm/hot climates

Radiant barriers excel at reflecting heat back to its source. If you live in a warm or hot climate, you will typically want to install the barrier on your rafters (the ceiling of your attic). This prevents heat from entering your home through the roof by reflecting it back towards its source. Using a staple gun, attach the radiant barrier directly to the rafters, allowing a 1–2″ overlap between sections.

Installing radiant barrier in moderate/cold climates

If you live in a cold climate, you will want to trap heat inside your home. You can do this by rolling the barrier across the floor of your attic, on top of your first layer of insulation. If your insulation doesn’t completely protrude above your floor joists, you can use a staple gun to secure the barrier, although this is not necessary.

However, a large portion of the U.S. experiences both climates.

Don’t forget to insulate any ductwork that may be present in the attic, which is a common practice in homes without basements or crawl spaces.

Step 4: insulate your attic opening

If you access your attic through folding stairs, you can insulate the opening with an attic stair insulator. For a simple door or small entrance, you can attach a piece of insulation to the attic side of the door. Sealing this entryway adds a final layer of protection, keeping the air in your home separate from the air in your attic, and allowing your insulation and radiant barrier to work effectively.

Final Thoughts on How To Install Insulation in an Attic

Now that you know how to insulate an attic, you can take pride in making your home more comfortable and efficient, while also reducing your energy bills for years to come.