Garage Door Insulation Foam Vs Fiberglass [Differences & Similarities]

Usually, homeowners think about insulating their homes and forget about their garages. Although this is not necessary if your garage is detached from your home. If it is a part of it then you have to think about insulating it. 

Although there are various methods and materials available in the market for insulating garage doors and walls, usually people prefer these two most dominant materials for insulation:

  1. Garage Door Insulation Foam
  2. Fiberglass Insulation

Here, homeowners confuse about which one is best for insulating their garage door between them. As per my personal experience, both the materials are best in their area, but in this article, we are going to find out the differences between them and which material is best for which condition.

So that you can make the right decision in choosing the right material for insulating your garage door. 

So without further ado,

Let’s break it down…

Before we dive deep into this topic let’s have a look at the below table that summarise the differences and similarities between them at a glance.

Differences Between Garage Door Insulation & Fiberglass Insulation

Garage Door Insulation FoamFiberglass Insulation
1. Garage door insulation comes in rigid and large pieces.1. Fiberglass insulation feels soft and comes in rolls.
2. Garage door insulation will cost you much higher than the other insulation materials. 2. Fiberglass insulation is cheaper than Garage door insulation foam. 
3. It is easy to install but cutting it into the right pieces is a little bit difficult. 3. Fiberglass insulation is easy to install than Garage door insulation.
4. After cutting it into small pieces the leftover small pieces have no use. It means it has wastage more than the fiberglass insulation foam. 4. Here, you can use small pieces of residue so no wastage at all.
5. Garage door insulation foam is moist and mold resistance. 5. Fiberglass insulation gets moist and causes mold growth because of tiny air pockets. This is not the case in garage door insulation. 
6. It doesn’t cause skin irritation during the installation and cutting process. 6. Fiberglass insulation causes skin irritation. You have to wear safety gear for cutting and installation.
7. Due to its high R-value Garage door insulation provide better heat insulation than Fiberglass insulation. 7. Fiberglass insulation is also a good heat insulator but not as effective as a garage door insulator.


—> Both are great in fire resistance and prevent air penetration within your garage. <—

Fiberglass Insulation Vs Garage Door Insulation Foam: [Which One Is Right For Your Garage Door]

To make things much easier to understand, we are talking about them based on some properties. Let’s find out which one is best under which category.

1. Material:

The insulation foam is made of Polystyrene, Polyisocyanurate, and Polyurethane foam plastic. These materials are known for good thermal resistance and can obstruct heat well. 

On the other hand, Fiberglass insulation is made of spun fiberglass. This is molten glass and made of 40 to 50% recycled glass content. 

2. Look And Feel

Garage door insulation foam is available in a large sheet, with the dimension of 4 x 8-foot sheets. These sheets are available in a thickness of one-fourth to two inches. Its structure is rigid and comes in a large rectangular shape. 

On the other Fiberglass insulation comes in a rolled foam. Its shape is flexible and feels softer than the rigid insulation foam. 

Fiberglass insulation is available in 24 to 40 feet rolls. The thickness of it varied from three and a half inches to twelve inches. 

3. Installation Process

Rigid foam insulation or Garage door insulation is a little bit difficult to install because of its rigid structure. You have to cut it down to use. Proper measurement is necessary for cutting. 

On the other hand, Fiberglass insulation comes in rolls, which are soft and very easy to install. However, you have to wear safety equipment because fiberglass small particles may irritate your body’s sensitive parts such as the nose, eyes, throat, lungs, etc. 

Also Read: Foam Board Vs Reflective Garage Door Insulation

4. Insulation Property

Usually, Rigid foam insulation provides much better insulation than Fiberglass insulation material due to its rigid shape, and thick body. 

5. Which Increases More Weight of Your Garage Door

Garage door insulation increases the weight of your garage door, and you may feel the difference in opening and closing your garage door after installing garage door insulation. 

On the other hand, Fiberglass insulation feels light and doesn’t increase as much weight as garage door insulation material does. 

6. R-Value

R-value describes the heat resistance property of insulation material. Rigid foam insulation has a higher R-value as compared to other insulation materials. 

Rigid foam insulation consists of Polyisocyanurate the R-value goes high up to 8.3. This is the highest R-value that any other insulation material can hardly touch. 

On the other hand, the Fiberglass insulation R-value (for Fiberglass butts) is between 3.1 to 4.3 which is low compared to rigid insulation material. 

Remember that the higher the R-value,  the better the heat resistivity of that material as compared to others. 

4. Cost

Fiberglass insulation is a cost-effective method to insulate your garage door. It will cost you much lesser than the Garage door insulation foam. 

The below table will clarify which one is cost-effective:

Total Installation Cost OfArea (Square Feet)Min CostMax CostAvg. Cost/Square Foot
1. Rigid Garage Door Foam Insulation250$449$800$1.80-$3.20
2. Fiberglass Foam Insulation250$352$622$1.41-$2.49


5. Applications

A garage door rigid foam insulation can be used for insulating garage doors, in tight or cramped spaces such as cathedral ceilings, floors, walls, roof rafters, etc.

Fiberglass insulation can be used in basement walls, garage doors, for insulating the existing walls, attic floor, for soundproofing, etc. 

6. Reusability Of Cut pieces

Due to their rigid shape and size, the residue of small pieces of rigid foam insulation can not be reused. 

On the other hand, Fiberglass insulation is flexible and soft and you can use its small pieces. It means there is very less wastage of material than rigid foam insulation. 

7. Which One Gets Moisture And Mold

Garage door insulation that is available in home depot and other online platforms is made of high-quality expanded polystyrene which is moist and mold resistant.

On the other hand, fiberglass foam insulation has lots of air pockets, which work as an insulated plate between the door and insulation foam, but these air pockets are prone to get moist and cause mold growth. 

Also Read: Sealing Gap Between Garage Floor And Wall [Solved]

Benefits Of Using The Right Garage Door Insulation Material

  • It saves you money on your energy bill.
  • It provides better insulation against heat loss and maintains a comfortable temperature inside.
  • It keeps things safe from the outside harsh weather conditions in your garage.
  • The garage door insulation is also a good soundproof material that minimizes outdoor noises and prevents them from entering your garage.

Also Read: Garage Door Opener Rail Bows When Closing[Solved]


Your garage is also a part of your home and it should not be neglected. You can utilize it in many ways. In winter to use this place for creativity and other purposes, you have to think about insulating its doors which is not a difficult task.

If you have any doubt about which insulation material should choose then I’ve mentioned every single detail about whether you should use garage door insulation foam or fiberglass insulation foam.

I hope this article will help you to make your garage more comfortable for you.


Does garage door insulation make a difference?

Q.1 What Type Of Insulation Is Best For Garage Doors?

Ans: It depends on what type of door has been installed in your garage. If your garage door is made of wood and is panel based then you have to use rigid insulation foam board for that purpose. But if it is made of metal then you can either use foam board or fiberglass foam insulation to insulate your garage door.

Q.2 Does Garage Door Insulation Make A Difference?

Ans: Definitely good garage door insulation can make a very noticeable difference in the heat insulation. After installing the garage door insulation you will clearly see up to a 10% improvement in your garage temperature.

About The Author

Harry walter

Harry Walter is here, I'm a passionate writer of home guides, backyard, and garage problems, and have been doing this for a couple of years. I love to share simple solutions for your home and backyard problems.

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