What to Know About Replacing Your Home’s Insulation

Scott Dylan Westerlund
Updated October 27, 2021
Cozy living room with gas fireplace
Jodie Johnson – stock.adobe.com

If the clock is ticking on your home's insulation, your energy bills are ticking upward

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If your house is sending you shivers and your energy bills are getting you hot under the collar, it’s probably about time to replace your insulation. The truth is that any insulation that is more than 10 years old may be out of sync with the latest recommendations from the U.S. Department of Energy. Find out how long your insulation lasts to decide if it's time to replace it for better energy efficiency.

How Long Does Insulation Last?

Insulation lifespan varies based on the materials used in your home. Take a look at what to expect from common types of home insulation.


A popular choice found in homes around the country, well-maintained fiberglass can last for 80 to 100 years. However, homeowners need to begin checking fiberglass for weak points by year 15. The earliest signs of failing fiberglass are fallen chunks on the floor or batts detached from frames.


If your home has eco-friendly, plant-based cellulose insulation, the expected life is 20 to 30 years. However, cellulose insulation can begin degrading at year 15. This happens because cellulose insulation is plant-based, so water, mold, bugs, and critters can chip away at it over time.

Mineral Wool

Age may just be a number, but there’s something to be said for mineral wood insulation, which can last for up to 100 years.

Spray Foam

Spray foam offers lifetime insulation as it can last for 80 years without any need for updates.

Batt Insulation: What You Need to Know

You may think you're in the clear because your home has an insulation material like fiberglass that was installed within the past 20 years. But you should check to see if you have blown-in or batt insulation. It’s easy to spot the difference—batt insulation will look fluffy, and blown-in insulation will look solid.

Batt insulation is a blanket-style insulation that is rolled in sections. Unlike blown-in insulation, batt insulation can begin to fall out at the 15-year mark.

What Factors Reduce the Lifespan of Insulation?

Several factors can shorten the lifespan of any type of insulation by decades. Here's a look at the common culprits that can cause insulation to lose its potency:

  • Severe weather

  • Water damage

  • Mold

  • Dust

  • Fire

Timing Is Everything: How to Know It's Time to Replace Your Insulation

Man changes the radiator temperature in his home
Piotr Marcinski - stock.adobe.com

Outdated insulation can throttle your home's heating and cooling. Feeling like the thermostat is saying something different from the feeling inside your house is a telltale sign that your insulation is fading.

Here's a look at some other key signs that your insulation needs replacing:

  • High energy bills

  • Uneven indoor temperatures

  • Draftiness

  • Moist or wet insulation

  • Indoor condensation

  • Pests

While other issues can sometimes cause these signs, your insulation is a great place to look first. You can actually glance at your insulation in your attic or unfinished rooms to spot telltale signs of disintegration. You can also take off outlet covers and look inside the wall—just be sure to turn off the power before you do. Look for:

  • Wetness

  • Thinning

  • Falling

  • Separating

  • Visible floor joists

Can Bad Insulation Make You Sick?

It's not just your home that can show signs of poor insulation. The people in your home can also experience unpleasant symptoms. When old, damaged insulation is left as is, it creates a perfect environment for mold and bacteria. This can trigger allergies and illness in some people.

How to Know If You Should Replace Your Insulation

The only way to get a read on your insulation's "true age" is to book an energy audit. During an audit, an insulation pro will inspect for "leaks" that indicate poor insulation. Many HVAC companies use infrared technology to catch gaps that homeowners can't see.

An audit will reveal one of three things:

  • Your insulation is fine (hooray!)

  • You don't have enough insulation

  • You need insulation replacement (don’t worry, we’ve got your back)

This information will help you  choose the next step for creating a healthier, more efficient home.

How to Choose New Insulation

Here’s an insider tip—when choosing new insulation, ask about R-value, which is the durability rating for insulation. Higher R-values are highly effective.

Ideal for most homes, the Energy Star recommendation for R-38 insulation provides 12 to 15 inches of padding. Homeowners in colder climates might want to consider R-49 insulation. Insulation contractors can recommend options based on the specifics of your home.

Now Enjoy the Benefits of Your Home’s New Insulation

Expect to see about a 15% drop in your home's heating and cooling costs after you replace or fortify insulation. You should also notice that dampness, pest issues, and uneven temperatures go away.

Fixing your home's insulation with a local insulation company is generally a quick process that doesn't require major reconstruction. If your existing insulation can stay, that dramatically reduces the cost of getting new insulation.

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