Can I spray foam my RV? (5+ options)

In this article, we will answer the following question: Can I spray foam my RV? We will review the best insulation materials for RVs and give you advice on what materials are better to avoid for RV insulation. 

Can I spray foam my RV?

Yes, you can spray foam your Rv if the intention is to insulate the underbelly of the vehicle. Spray foam is a common thermal insulator used mainly for floors. The advantage of spray foam is that it is airtight and easy to apply. When sprayed, this foam expands, which allows it to reduce thermal bridges found at the connections between walls and roof or between walls and floors.

Insulating foam is the simplified term that is used to denote sprayed polyurethane foam. This foam has the advantage of being able to be used in all types of habitats, including RVs. 

What are the advantages of spray foam for RVs?

Unlike mineral wools which eventually settle over time, foam insulation is more stable and that is just one of its many benefits.

Exceptional insulating capacitiesInsulating foam owes its performance to its micro air bubbles which prevent the cold from entering the RV. Conversely, these micro air bubbles help keep the heat inside. 
Thus, the insulating foam provides an optimized performance depending on the space to be heated.
100% airtight insulationAs it develops a liquid texture from the beginning, foam insulation can fill even the smallest cracks in a space that makes itself completely airtight. Since all the interstices are sealed, no heat loss is possible.
Environmentally friendly insulationUnlike other insulators, the foam does not contain VOCs or other toxic elements. It is also odourless. In addition, it does not generate microparticles in suspension.
Very resistant insulationAs a foam, this insulation is soft and malleable. Once hardened, it turns into a firm and unbreakable block. In this form, the foam cannot settle. It is also rot-proof. 
A very light insulationInsulating foam is 99% air. It is therefore the lightest solution for insulation. 
Insulation that lets the RV breatheThe spray foam is permeable to water vapour. Thus, there is no need to install a vapour barrier on the RV. The latter will be able to breathe properly.
Easy-to-apply insulationAs has been mentioned several times, foam insulation can go in anywhere. It is the perfect solution for hard to reach places. By eliminating all thermal bridges, the insulating foam guarantees optimal thermal insulation.
An ecological insulationDon’t be fooled by the industrial character of insulating foam. It is completely ecological. Moreover, the products that are offered on the market have received environmental quality labels.

Spray foam does not only have physical or technical advantages. It also has a plethora of financial benefits.

Thanks to the spray machine, the application of the insulating foam takes half the time. When projected onto a support, the foam dries immediately. In general, it takes a day to complete a site of several sq ft. As this foam is most often applied by machine, the intervention of professionals is strongly requested. 

What are the disadvantages of spray foam for RVs?

Despite its exceptional advantages, the insulating foam has a few drawbacks:

Poor sound insulationUnfortunately, spray insulation is not a good sound insulator. External sound interference remains audible unless the thickness of the foam is very generous.
Negative impact on global warmingSome varieties of polyurethane insulation foams have a negative impact on global warming due to their blowing agents. 
However, some manufacturers have already found a solution to this problem. Insulating foam based on hydrofluoroolefin and icynene is reportedly under development.
Difficult to removeWhen it has hardened, the foam will adhere to the wall. In fact, it will become one with the wall/floor. It will be difficult to remove it.

How do you spray foam an RV?

To be precise, insulating foam is used for the insulation of surfaces that come into contact with the outside, namely: walls, floors, ceilings and the roof. Moreover, the foam itself can be covered with concrete which will serve as a support for the tiling.

Thanks to its consistency, the foam insulation can be applied to wood, plaster, stone and concrete. The application of the foam is done by means of pneumatic and hydraulic machines, which is why only professionals are authorized to carry out this kind of project. The insulating foam is compatible with heated floors.

Alternative materials for insulating an RV

Below we present some alternative methods of insulating an RV, each with its own advantages and disadvantages: 

  • Extruded Polystyrene (XPS) and Expanded Polystyrene (EPS): Both petroleum-derived materials have good insulation characteristics and are also quite impermeable to vapour (XPS more than EPS). 

Like all non-flexible materials, its main drawback is that it does not conform well to the creases of the van, but it can be a good material to place on the ground and between the beams of the walls and ceiling. There are many qualities of expanded polystyrene (also known as white cork or polystyrene), so if you use it, ask first about its capabilities as an insulator.

However, these materials are not very environmentally friendly and burn easily in the event of a fire. In addition, in doing so they release gases that can be toxic to health.

  • Cork insulation: Cork is a material where moisture does not appear or creates mould, but on the contrary, it has to be permeable, so that water can pass through it and create humidity and condensation. Therefore, it is essential to put it next to some material that makes a vapour barrier (reflective aluminum materials, for example). It can be used to insulate the floor in a single piece, since being a resistant material it will not split.

However, due to its limited flexibility, it is not recommended to use it for other parts of the van.

These types of insulators are the best to put on an RV as they conform to shapes and curves perfectly. On the other hand, they tend to be more expensive materials than non-flexible insulators.

  • Rock wool and fibreglass: Rock wool and fibreglass are excellent materials for thermal and acoustic insulation. They are materials widely used in the construction of houses due to their qualities.

For an RV it is also a very good option, since it adapts very well to the curves of the van, and it can be put inside the beams themselves (It can be crumbled). However, it must be installed correctly.

Keep in mind that it is a very porous material and does not serve as a vapour barrier. In addition, all the moisture is trapped inside. Therefore, it must be installed together with another material that acts as a vapour barrier and prevents condensation.

One way to apply it is with aluminum foil (better if it is multilayer) so that all the rock wool is covered by the reflective material. There are also brands like Rockwool or Isover that sell rock wool with a layer of aluminum foil that already acts as a vapour barrier.

Be that as it may, it is never the first barrier of protection against humidity and steam, since otherwise, the wool would remain damp and moisture would be generated, and with it, the dreaded rust will appear.

Rock wool and fibreglass are similar materials but of very different origins. Rock wool comes from volcanic rocks heated at high temperatures, while fibreglass comes from glass threads that have also been melted at high temperatures. Fibreglass is less dense than stone wool, so it weighs less. However, fibreglass is very irritable in contact with the skin and eyes, so if used, it is advisable to wear gloves, goggles and a mask.

  • Ecological alternative: A material very similar to rock wool, but of ecological origin, is the Geopanel. It is an insulator with the same insulating properties, but whose components come from 85% to 100% recycled materials. It is more expensive than stone wool, but the main advantages are that they are more sustainable and that it is also not a material that irritates when installing it. 


Spray foam is a material that is often used in construction to seal. It can be useful to fill the beams with this material due to its easy placement. However, it must be taken into account that it is a very porous material and that it can create humidity very easily. 

In addition, unlike rock wool, once inserted between the beams it is very difficult to remove it in case we need it, since it adheres to the floor of the RV, so it is better to avoid it. Although if you want to use it, it can be a good alternative!

Please feel free to share your thoughts and comments on the content. 

FAQ on Can I spray foam my RV?

How to insulate an RV for the winter?

A little extra insulation, such as curtains and rugs, makes it more comfortable in winter. So, take out the thick bedding or invest in an electric blanket, it will help. Park your RV so that the windows face the sun during the day.

How to store an RV?

Here are our tips for winterizing your RV to protect it against bad weather:

  1. Empty the tanks and the water heater. 
  2. Close the water inlet. 
  3. Pump the antifreeze with the water pump. 
  4. Empty the antifreeze. 
  5. Proceed with caulking. 
  6. Remove the batteries and shut off the propane. 
  7. Clean the RV.

How to insulate a trailer floor?

Foam insulation is the most used product for insulating a trailer roof and it is found everywhere on the market.


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