From types of insulation and materials to target R-values and installation, this article breaks down what to consider when insulating your attic yourself.

Insulating Your Attic Can Save You Money

Insulation Types and Material

Insulating your attic can save you a lot of resources.

There is no getting around it: If your house is in a cold climate, keeping it warm in winter is costly. The Department of Energy predicts that the costs of natural gas and heating oil will rise again this winter compared with last—and that is after a year, heating-oil prices rose sharply in most parts of the country.

Sure, you can dial down the thermostat and get used to wearing bulky sweaters indoors to cut expenses. But if you’ve got an unfinished attic, giving it proper insulation is one of the easiest ways to keep a lid on your heating bill this season. “It is a DIY project you can tackle in a weekend, and the savings you will get add up every year,” says TOH general contractor Tom Silva. The Department of Energy estimates that a correctly insulated attic can shave 10 to 50 percent off your heating bill. And it works the opposite way for warm climates; in summer, it helps stabilize your house’s indoor temps to keep cooling requirements in check.

In a perfect world, you would hire an energy auditor to tell you exactly how much protection you are getting from the few inches of attic insulation you may already have and pinpoint things like air leaks that you can seal to ensure your insulation will do its job well. But if you cannot afford to shell out a few hundred bucks for this service, never fear.

Attic Insulation Costs

According to Home Advisor, insulating your attic can cost between $1700 to $2100. The main factors that contribute to the cost are:

  • Kind and material of your insulation
  • Square footage of your attic
  • Contractor or insulation installer’s payment

Note: If you have to insulate around electrical boxes or cables, then support from an electrician might be required as part of the process too.

Begin with The Attic Floor

Halt using your attic for storage. Why? Since the simplest and cheapest way to insulate an attic is to add material to the floor. But if the floor is covered in plywood, you cannot stuff enough insulation beneath it to do the work sufficiently—not even in warm climates.

Try to pull up the flooring and layer new insulation on top of the old. With the floor gone, you will have to find a spot elsewhere for stashing those off-season clothes and that holiday decor.

Select Your Insulation Type and Material

Foam Board Insulation

Types of insulation materials can be added to uninsulated attics or layered over current material.

For DIY attic insulation, you have got two options: loose fill or batt (the common term for blanket insulation). Both can be added to uninsulated attics or layered over current material. After you’ve decided which type is best for you, examine the material choices and prices to home in on the right product. Always check labels for specifics on whatever you purchase.

1. Loose fill

Insulation fibers are packaged in bags and blown in place to the anticipated depth and density using special machinery you can rent from a home center. You can pour the fill in place and spread it manually, but the process is much more labor-intensive, and the results would not be nearly as good.

It works best for:

  • Low-clearance attics with limited headroom for movement during installation
  • DIYers who want to get the work done quickly and are comfortable working with power equipment
  • Attics with many obstructions and penetrations to workaround
  • Attics with uneven or nonstandard joist spacing
  • Attics where there is existing insulation to be topped because it fills gaps and joints well

2. Batts

This flexible insulation material is most often packaged in rolls that come in numerous thicknesses and standard widths, typically 16 inches and 24 inches, to fit between joists or studs in a house’s framing. They come with or without a paper or foil facing that acts as a vapor wall. You add one or more layers to attain the desired level of insulation.

They work best for:

  • DIYers who do not mind cutting the material to fit around barriers
  • Attics that have sufficient headroom for maneuvering during installation
  • Attics with standard joist spacing, particularly those with no insulation
  • Attics with few obstacles or penetrations to workaround

References and Resources