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Does a Crawl Space Need Insulation? (7 Benefits to Consider)

Does a Crawl Space Need Insulation? (7 Benefits to Consider)

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A crawl space is a structure that creates a gap between your house and the ground. Sometimes it’s used to conceal plumbing pipes, electrical wires, and HVAC equipment.

Does a crawl space need insulation, though?

In this post, we’ll talk about the reasons why you should insulate your crawl space, what type of insulation to use, and much more. So, stick around!

Why Insulate a Crawl Space

You’ll be happy to find out that insulating your crawl space has a lot of benefits for both you and your home. Here are the reasons why insulating this dark and dingy place is crucial:

1 – Saves Energy

According to the Environmental Protection Agency (EPA), installing insulation in your crawl space can save you up to 15% on energy consumption.

When your crawl space lacks insulation, your home requires more energy to heat up or cool down the interior temperature.

By insulating the crawl space, you can regulate the temperature in your home, leading to reduced electricity usage.

2 – Keeps Away Pests

A dark and damp crawl space is enticing for unwanted pests.

Insulating your crawl space creates a barrier that denies crits the opportunity to nest and breed in the area.

Also, insulation fills gaps in the walls, effectively preventing vermin from entering your house.

3 – Reduces Moisture

Insulating your crawl space plays an important role in moisture reduction.

Without insulation, moisture accumulates in the crawl space, leading to mold growth and wood decay.

Since the crawl space is interconnected with your house, it affects the temperature of the space above, resulting in a colder environment during winter and compromising overall comfort.

4 – Improves Indoor Air Quality

The presence of mold and mildew anywhere in your house is highly undesirable.

These contaminants can pollute the air you breathe indoors, leading to various health issues and respiratory problems.

By insulating your crawl space, you create a barrier against mold and mildew, ensuring better indoor air quality.

Additionally, insulation acts as a filter for incoming air, preventing pollutants from entering your home.

5 – Provides Added Storage

Opting for insulation transforms your crawl space into a valuable storage area.

It becomes a secure and convenient space to store your belongings, providing an alternative storage option within your home.

6 – Adds Value to the House

An insulated crawl space is indicative of a homeowner who prioritizes proper maintenance of their house.

In case you’re planning to sell your house in the future, this aspect can serve as a selling point for potential buyers evaluating the property.

7 – Extends the Lifespan of HVAC Equipment

Your HVAC system and crawl space may not appear to be directly related, but the absence of insulation in your crawl space can significantly impact your HVAC equipment.

Without proper insulation, the crawl space becomes the source of added strain on your HVAC system reducing its lifespan.

The air from below seeps through the floor, causing the air to become warmer. As a result, your HVAC system is forced to work harder to maintain the desired temperature levels.

What Type of Insulation to Use for a Crawl Space

When you decide to insulate your crawl space, there are several options to consider. Let’s explore each of them to help you choose the best option.

1 – Fiberglass

This is the most common type of insulation used in crawl spaces of older houses. It typically comes in the form of a blanket or mat.


  • Provides effective warmth and insulation for your floors.
  • Relatively easy for experienced homeowners to install.
  • Inexpensive and readily available at home improvement stores.


  • Tends to absorb moisture, leading to potential sagging and deterioration.
  • May attract rodents due to the warmth it provides.

2 – Spray Foam

Spray foam is a plastic-based insulation that is applied as a sealant and insulation, conforming to the framework and walls once sprayed.

There are two types: closed-cell and open-cell, distinguished by their cell structure.

Open-cell spray foam creates a network of bubbles, resulting in a softer and more flexible material. On the other hand, closed-cell spray foam, being the opposite, fills its cells without leaving any room, yielding a more compact structure.


  • Allows the floor framing to breathe, preventing moisture from becoming trapped within the insulation.
  • As it doesn’t retain moisture, molds and mildew are less likely to thrive.
  • Critters don’t favor this material as a source of shelter or food.


  • Installing this insulation may not be an easy DIY project for an average homeowner and requires the assistance of a professional contractor.
  • Compared to other traditional types used in crawl spaces, this type of insulation is more expensive.
  • Some spray foams may emit an undesirable odor after application, which you may find offensive or overpowering. Make sure to be familiar with the brand before buying.

3 – Foam Board

Foam boards are panels made from materials such as expanded polystyrene (EPS) or extruded polystyrene (XPS).


  • Boasts a high R-value, indicating excellent insulation efficiency.
  • Effectively controls moisture, prevents air leaks, and reduces thermal bridging.
  • A versatile material that’s suitable for insulating not only crawl spaces but also other areas in your home.


  • Foam boards are generally more expensive than other forms of insulation.
  • Proper installation is very important to fully benefit from its insulation properties. Hiring a contractor would be a better idea to ensure correct installation.

4 – Blown-In Insulation

Blown-in insulation, also known as loose-fill insulation, is a process where materials such as fiberglass, cellulose, or wool are blown into crawl spaces using a hose attached to a blower machine.


  • Excels in its ability to settle and adapt to various shapes and obstructions found in crawl space walls and frames.
  • Using this type of insulation is relatively economical, and despite its affordability, it offers a commendable R-value.
  • Most materials used in this insulation are environmentally friendly.


  • Some materials used in this insulation, such as cellulose, tend to pack down more easily, potentially creating gaps at the top of spaces.
  • Cellulose insulation tends to absorb moisture within enclosed areas, leading to extended drying periods.
  • Due to its moisture retention, it provides a conducive environment for mildew and mold growth.

Final Thoughts

Insulating your crawl space is a good step towards optimizing your home’s energy efficiency and comfort. By insulating this often-neglected place, you can improve indoor temperature regulation and power consumption.

Taking measures to insulate your crawl space not only enhances the overall performance of your home but also contributes to a healthier and more sustainable living environment.

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