Best Insulation for Mobile Home Walls

If you are looking to insulate your mobile home and you are asking yourself what is the best insulation for your mobile home, you will need to understand what your needs are. In this article we will cover the two most common insulation needs for people who are going to insulate their mobile home and the best insulation that suits those needs. 

  1. Overall thermal resistance 
  2. Cost effectiveness 

Best Insulation for Thermal Resistance 

Closed cell foam is a type of insulation made of closed cells that don’t allow in air or moisture due to their compactness. Closed foam is made of isocyanate and polyol resin compounds which come in two different spray cans. The cans are usually labeled side A and side B and are only mixed on the site. 

Upon application on a surface, closed cell foam fills all cavities and rises to 100 times its original size. Closed cell when dry is more rigid and gives structures more strength and energy efficiency. 

The R-value of closed foam insulation lies between 6 and 7 per inch and determines how well it resists heat flow. The insulation doesn’t allow heat loss or heat gain and has the best thermal resistance compared to all other types of insulation. 

How to Install Closed Foam on the Walls of  mobile Home 

The method of insulation you use on the walls of your mobile home totally depends on the siding your home has. As a standard, sidings of a mobile home can be installed either vertically or horizontally. 

Most vertical sidings are made of aluminum or vinyl. You cannot completely remove an aluminum or vinyl siding when insulating the walls. Instead, you should cut a strip of the siding and then make some holes on the stud gaps. Then, you want to make sure you inject the right amount of foam in the stud cavities through the holes you’ve made. Finally, seal the holes using caulk and replace the strip of siding you had cut. If there’s excess foam, you also want to make sure you clean it out of the walls. 

Most horizontal wall sidings are made of wood or brick. Depending on the condition of the wood, you can either completely remove the wood or drill holes on the wood. If you remove the wood siding, spray foam in between the wall cavities. After that, put back the wood and clean any excess foam. 

If it’s impossible to remove the wood siding completely, then you need to drill holes on the wood. Through the holes, inject the spray foam making sure it fills the wall stud cavities. Finally, seal the holes using wood plugs. 

If the siding is made of brick, you don’t need to remove the bricks. Instead, drill some holes along the mortar joints. Inject foam through these holes and after that seal them using mortar. 

Benefits of using Closed Cell Foam on Mobile Homes 

Are you wondering why you should use closed cell spray foam on the walls of your mobile home and not any other type of insulation? Here is why. 

  • Structural integrity 

Due to the rigidity of closed cell foam, upon drying it makes the structure stronger. 

  • Moisture resistance 

If you’re worried about moisture and water leaks in your home, closed foam can be the best solution. The insulation fills gaps leaving no spaces that can allow moisture leaks. Moisture leakages can lead to buildup of mold and mildew that can affect your health. 

  • Air seal 

You don’t have to endure all the drafts and unconditioned air in your mobile home. You can make the space more comfortable by insulating with closed cell foam because it forms an air seal preventing air infiltration. 

  • Thermal resistance 

Mobile homes can be very uncomfortable especially during extreme weather changes. When you insulate with spray foam, it prevents heat flow in and out of your mobile home making it more comfortable. 

Downsides of Closed Cell Foam In a Mobile Home 

Here are some of the disadvantages you may have with using closed cell foam on the walls of your mobile home. 

  • Expensive 

Truth be told, closed cell spray foam is expensive. To cover all the walls of your mobile home, you might have to spend a significant amount of money. If you’re operating on a budget, then it may not be the best for your needs. 

  • Not really a DIY project 

Insulating a mobile home may not be as easy and quick as other types of buildings. You may need to use specialized equipment to drill through holes or even seal them. Therefore, for the insulation of the walls of a mobile home, you might want to hire an expert. Of course, this means you’ll have to incur an extra cost. 

Best Insulation for Cost Effectiveness 

If you’re operating on a budget, you can use fiberglass insulation in place of closed cell spray foam. Fiberglass comes either in rolls or batts depending on your preference. But what exactly is fiberglass insulation? 

Fiberglass is made of molten plastic that is then strengthened using fine glass fibers. Fiberglass has an R-value of between 2.9 and 3.8 per inch. R-value is the measure of how well an insulation can regulate heat flow. 

Step by Step on How to Install Fiberglass Batts into your Mobile Home Walls 

The process of installing batts in a mobile home is quick and simple unlike spray foam. However, the applicability of batts and rolls on the walls totally depends on the type of walls you have. The best type of walls are those you can quickly remove and place back such as wood sidings. 

The first step is to wear some protective clothing because the fibers can irritate your skin and lungs if inhaled. Next, you want to remove the wall sidings to expose the wall cavities. When fitting in fiberglass in the wall cavities, make sure they snugly lie in between the studs. 

Avoid stashing so many batts on one cavity because you’ll interfere with the R-value. Fiberglass insulation works best when there is enough air in between the batts or rolls. After you’ve stapled the batts/rolls on the wall cavities, place back the wall siding. 

What are the other benefits of Fiberglass in relation to mobile homes 

Other than being cost effective, fiberglass has other benefits when used to insulate a mobile home as detailed here. 

  • Thermal resistance 

With fiberglass, you can regulate heat gain and heat loss from your home. This means that your home can be more comfortable without having to spend so much on air conditioning. 

  • Easy to install 

Unlike closed cell spray foam, fiberglass is easy to install in a mobile home and can be a do it yourself project.

Downsides of Using Fiberglass to Insulate the Walls of a Mobile Home 

Despite the advantages, fiberglass insulation has its cons in relation to mobile homes.

  • Water permeable 

Fiberglass doesn’t protect against moisture buildup. Instead, it absorbs the moisture but which can dry up eventually. 

  • R-value decreases 

The other disadvantage of using fiberglass is that the R-value deteriorates over time. This means that the insulation could become ineffective in the future when its thermal resistance has decreased. 

  • Can trap dust

If you’re concerned about dust and other allergens in your home, then fiberglass is not the best choice. The fibers tend to trap in dust and pollen which can cause respiratory problems. 


Mobile homes are affordable and make great spaces. However, they require proper insulation to make them more comfortable. The best type of insulation for the walls of your mobile home is either closed cell spray foam or fiberglass insulation. Each insulation has its pros and cons and you need to weigh your options depending on whether you want maximum thermal resistance or a cost effective insulation.