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Insulation for Mobile and Modular Homes

What is the best insulation for mobile and modular homes? Learn about 3 types of mobile home insulation: fiberglass, foam board, and foam.
insulation for mobile and modular homes

It may surprise you that most homes in the United States aren’t insulated properly. In fact, around 90% of homes are under-insulated. Building codes haven’t always been what they are today. Mobile homes built before 1976 may have as little as 1 inch of insulation in them, if they have any at all.

As technology has advanced and the field of building science has grown, we have been able to understand more about the value and benefits that insulation adds to our homes. We know now that the parts do not work individually but as a system. If everything is up to par, that system can make your home a very efficient and comfortable place.

Why should I update the insulation in the walls of my mobile or modular home?

According to the Insulation Institute, “Since 2004, residential electricity prices across the U.S. have risen nearly 40%, and changes in the utility industry suggest this trend is likely to continue.” Every month you pay a portion of your hard-earned income to keep your home comfortable. In the winter, you pay to keep it warm. In the summer, you pay to keep it cool. But every day, some of that comfortable air you pay for is escaping. As air is leaking out of your home, money is leaking out of your wallet. Would you rather your money go to waste, or would you prefer to put it towards something that will increase your comfort, increase the value of your home, and save you money in the long run?

The National Renewable Energy Laboratory and the U.S. Department of Energy teamed up to run tests on older and newer mobile and manufactured homes. They found that adding insulation to the walls of a mobile or manufactured home reduced heat loss by up to 13 percent! That may not seem like a lot, but thirteen percent repeated every month can add up! Imagine not only saving money but not having to worry about a room constantly being too hot or too cold. Your home is your refuge from the hustle and bustle of everyday life. It should be a place of comfort, and adding/updating the insulation in the walls of your home can help you achieve that.

What type of insulation should I add to my mobile or modular home?

Once you’ve decided to add or update the insulation in your modular or mobile home, the next step is deciding what type of insulation you should add. There are several options from which to choose. It boils down to what your budget will allow and what you hope to get from your insulation.


Fiberglass insulation is the most common type of insulation out there. It can deliver effective R-values for your home. You can have it installed in two different forms, batts/rolls or blown-in. Fiberglass batts/rolls are large pieces. Blown-in fiberglass is precisely as it sounds. A tube inserted into your wall, blows small pieces of fiberglass into the wall cavity. The blown-in fiberglass can fit irregular-shaped spaces much easier than batts or rolls. This video shows how fiberglass can be added to your home from the outside.

While fiberglass is relatively easy to install, it does have some downfalls. Incorrectly installed fiberglass drastically decreases the R-value and effectiveness. One of the reasons that fiberglass can work is because of the space between each of the fibers. It will not provide the promised comfort if the fiberglass is compacted due to improper installation or because it has to fit around wires and pipes.

It is also not a vapor barrier, meaning it is prone to trap moisture. As fiberglass traps moisture, it loses effectiveness and becomes a breeding ground for mold and mildew. Another downfall to fiberglass is that critters love it. If they can access the inside of your wall, it is possible that they will build a home there. Just like it helps keep your home comfortable, it keeps them comfortable too. Also, fiberglass does not create an air seal in your home, so your home can still leak air.

Foam Board

Foam board is another option for your home’s insulation. It comes in large sections that installers can cut down to fit the wall cavities in your home. Foam board offers high insulating properties and is less thick than fiberglass. It is more expensive than fiberglass and harder to install. Even though it can stop the conduction of heat, the transfer of heat through touch, it cannot eliminate convection, the transfer of heat through air movement.

Spray and Injection Foam

At RetroFoam of the Carolinas, we specialize in spray and injection foam. They offer incredible benefits, but whether or not we spray or inject depends on the status of your home. For homes under construction, spray foam is installed prior to drywall installation. For existing homes, we can come and inject the foam into the walls of your home from the outside.

Foam is an excellent product because it offers so many benefits. Some of these benefits of foam insulation include:

  • Creating an air seal as it is able to get into all of the nooks and crannies inside of your wall. It sticks to surfaces and can stop air convection through the walls.
  • It offers high and more constant R-values.
  • It acts as a vapor barrier which means that it keeps moisture from unwanted areas, like inside your wall cavities.
  • Although it does not make your home soundproof, it certainly dampens the sound coming into your home and the outside world.
  • It does not promote mold and mildew growth, and since it creates an air barrier, it can help keep allergens out of your home.

Contact RetroFoam of the Carolinas

We would love to talk to you about all of the benefits that our product can offer you. Our goal is to make your life more comfortable in your home and wallet. Contact us today so we can help you take the first steps toward that comfort.

Essential Buying Guide For Injection Insulation


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