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How Much Insulation Do I Need In My Attic

By December 23, 2021No Comments
Insulation measurement depth

The cooler months have begun and you have set your thermostat accordingly. As the days go by you do not notice a big change in your home. It still feels cozy and warm to you. The first bill comes in and it is as reasonable as it can be, considering it’s the cooler months and the heat runs longer. Then, the next bill comes in and it is quite a bit higher.

You begin to question why you are losing so much heat and the HVAC unit is working harder to maintain your warm and cozy place. It is clear to you that the home’s insulation is possibly failing you so it is time to take a look in the attic. How much insulation do I need in my attic? Depending on where you live the insulation range is from 4 inches to 18 inches.

Let’s take a look below at what’s involved and learn more details regarding attic insulation.

Spray foam attic insulation
Spray foam attic insulation

How Do I Know

Feeling the loss of heat in the cooler months or cooler air in the warmer months is a great indication of the need for more insulation. It is possible that you need to seal up some openings in your attic space. Before you add the new or additional insulation to your attic, you can foam seal around small cracks. Also, you should ensure that all openings around recessed lighting, wall plates, and the chimney flue are sealed.

Take a look below at the map of the recommended insulation levels and the zones in the U.S.

Zones for recommended insulation levels.
Courtesy of EPA website
Recommended insulation levels.
Courtesy of EPA website

Consider where you live as a guide to how much insulation you should have in the attic. The recommended depth in southern states is 13 to 14 inches deep with an R-value of 38 in the attic space. The recommended depth in the northern states is 16 to 18 inches deep with an R-value of 49 in the attic space.

The R-value stands for the resistance to heat flow. The higher the R-value the thicker the insulation.

What Are My Options

There are a variety of options when it comes to insulation. It is best to take a look and see what is currently in your home. From there, you can make an informed decision as to which one to add or update. Let’s take a look at the options.

  1. Spray foam insulation-the most popular and reliable insulation. It does not move unless cut out or disturbed by animals. Also, it is not eco-friendly.
  2. Cellulose insulation-blocks air movement and eco-friendly. Life span is not that long and it breaks down after 15 years. Also, it consists of recycled material and lasts 20-30 years.
  3. Fiberglass insulation-if not disturbed or damaged by water, it lasts 80 to 100 years. However, if moisture is present, the insulation fails in as little as 15 years to 20 years.
  4. Mineral wool insulation-available in all three ways of rolls of insulation, blown-in insulation, or batt insulation. Typically, it lasts 30 to 80 years depending on the environment that it is exposed to.

Oftentimes, the type of insulation used is consistent with the budget and supply available to the builder and older homes are always in need of an insulation upgrade. In addition, while updating your attic insulation, it is a great idea to update the wall insulation of the home.

Attic insulation roll
Attic insulation roll

How Much Does It Cost

New attic insulation can cost you a pretty penny. However, it is a necessary investment that can save you money over time. Consider the insulation as an investment into your electric bill reduction. The national average for insulation ranges from $1,700 to $2,100.

The price range varies based on where you live, the type of insulation chosen, the contractor that you hire, and the size of your attic space.

Other Recommended Maitenance

Since you are on the topic of your attic space. It is a great time to determine the ventilation needed for the attic space. Believe it or not, an attic should be ventilated just as much as it should be sealed. Ask yourself, do you need an attic ventilation fan? Depending on where you live will answer that question. Ventilation might be part of your home already.

While you are up in the attic and determining the amount of insulation needed to replace or add to the attic space. Consider doing a thorough inspection of what needs cleaning. Oftentimes we neglect the attic crawl space and it becomes dirty and full of mold or mildew. Cleaning the attic crawl space is an important part of home maintenance.

Finally, it might not be so easy to get up into the attic. Some homes are built with just a scuttle attic in the home or the garage space. This then requires you to bring a ladder in and out of the house and have someone hold the ladder while you go up into the attic. This is a great time to look into having a scuttle attic ladder installed.

Professional installing attic insulation
Professional installing attic insulation

When Do I Call A Professional

Calling on a professional is vital for this project. Using a professional contractor allows you to have the attic inspected in full detail so that you can fix any issues. Typically, adding or replacing insulation is a key component for maintaining the integrity of heat loss or cool air loss. Also ensuring that all areas of the attic are sealed can prevent leaks and the loss of energy from your living space.


The attic space is most often utilized for the storage of holiday decorations and other boxes that don’t fit in the garage. In some cases, attics are also used as a workspace. Ensuring that the attic is sealed and fully insulated is a key portion of storing items successfully or using the attic as a comfortable workspace. Also, a home inspection can tell you if there are openings or cracks that should be sealed up and a recommendation for the amount of insulation needed can be made. Give your local home inspection team a call, Avalon Home Inspections, we conduct home inspections in Greenville, SC, and Atlanta, GA.

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