How Long Does Attic Insulation Last

While up in the attic to get down your holiday decorations, you begin to look around the attic space. You are taking a look to ensure that everything is still sealed up and as expected. All of a sudden, you notice that some of the insulation appears damp and damaged. Clearly, the insulation cannot do its job if it is damaged or wet. Thinking about how long you have lived in the home or how long the insulation has been around is very important.

How long does attic insulation last? Attic insulation longevity is based on conditions of exposure to elements and how sealed the home is.

Let’s take a look below at some more specifics regarding attic insulation.

Blown-in insulation in the attic
Blown-in insulation in the attic

Various Types Of Insulation

Believe it or not, there are various types of insulation that can be used in your attic to provide the home with insulation and protection. You may or may not be aware of the various types of insulation, so let’s take a look.

  1. Fiberglass insulation-this type can last 80 to 100 years if not disturbed or damaged by water. If moisture is present, this insulation can fail in as little as 15 years to 20 years.
  2. Spray foam insulation-a very popular and reliable type of insulation. Once it is sprayed in, it does not move unless cut out or disturbed by animals. Life span is not exactly clear and it is likely not very eco-friendly.
  3. Cellulose insulation-very effective at blocking air movement and eco-friendly. Life span is not that long and will start to break down after 15 years. You might see a range of 20 to 30 years with this recycled insulation material.
  4. Mineral wool insulation-available in all three ways of rolls of insulation, blown-in insulation, or batt insulation and lasts 30 to 80 years depending on the environment that it is exposed to.

Keep in mind that often the builders of the home choose which insulation to use and a cheaper route is always in their best interest. If you have an older home, it is best to take a look at a possible upgrade of your attic and wall insulation to create more energy savings. Also, if there is no mold or moisture, you can apply blown-in types of insulation to fill any gaps and crevices directly on top of the existing insulation. Our company is not a fan of spray-foaming antique homes. Contact us for our verbal opinion on this material.

How Do I Know It’s Time To Change

There are various reasons for you to change your attic insulation. Typically, any of the various scenarios are a clear indicator that the homeowner should make these changes. Let’s take a look at the list of those scenarios.

  1. Energy Bill-if you are noticing a higher energy bill than usual. This could be an indicator of needing an attic insulation change.
  2. Drafty-as you walk around your home, you notice various drafts giving you a chill. Additionally, a drafty house means the attic is not as sealed as it should be.
  3. Allergies or illness-one indicator is that poor insulation might cause mold to breed and this can contribute to poor health.
  4. Temperature changes-if you notice that the air conditioning is constantly changing as the temps appear uneven in the home.
  5. Ideal temps-it is near impossible to keep your temperature settings at their desired point. Setting the temps at 78 is a great idea. Also, if the temperature bounces up and down to adjust rather than maintaining is an indication as well.
  6. Pests-noticing a consistent pest infestation or many more insects than usual. Proper insulation can keep those insects and pests from coming into the home.
  7. Damp or soggy-if you have a leak or other moisture issues the insulation will become soggy and wet. This is not good as it breaks down more quickly and is not able to keep your home insulated as needed.
Roll of attic insulation
Roll of attic insulation

How Much Does It Cost

Luckily for most homeowners, the replacement of attic insulation is relatively cheap. You are looking at a price point per square foot and as long as you don’t have a huge attic, this should not be an exorbitant cost. The average cost to replace your attic insulation ranges from $2 to $8.50. An additional fee of $1 to $1.50 per square foot is to remove the old attic insulation. The easiest solution is adding blown-in insulation or spray foam on top of the existing material.

While you are researching how long attic insulation lasts, you can also look into whether or not you can add insulation over electrical wires in the attic. However, It just might be time to change out the old insulation. Also, while you are upgrading the insulation, it is important to determine the types of wires in the attic so that you can prevent a fire.

Since we have spoken about temperatures in your home and the need to update or replace your attic insulation, it is important to note how you can keep the attic cool in the summer months. Additionally, understanding this process allows you to maintain the desired temperatures in the home. It prevents warmer air from cruising upwards to the attic and allows the attic to stay cool.

Finally, when it comes to attic insulation, you should make sure that you conduct a home inspection. Even after you have purchased a home, you want to make sure that all areas of the home are in top shape. At the very least, you need to know what repairs are necessary to maintain a healthy and safe home.

Professional rolling in attic insulation
Professional rolling in attic insulation

When Do I Call A Professional

Calling on a professional to remove your attic insulation and install new insulation is always a great idea. As the homeowner, you do not want to get involved with the safety concerns of replacing attic insulation. In addition, the crawl space that might not be big enough for your to maneuver in is always a concern.

Finding the right professional contractor is the best bet here. Call on your local home inspection team to inspect your attic and then provide a recommendation for a professional contractor to complete this project.


Utilizing someone who understands the timing in which attic insulation should be replaced is vital to your success as a homeowner. Calling on your local home inspection team to look over your attic insulation while they conduct a full home inspection is also money well spent. A lot of issues could be solved with regards to the sealing of the attic and keeping the home properly insulated.  Twin State inspections will conduct a quality home inspection in the Twin State areas of VT, and NH.