RV Insulation: The Ultimate Guide

RV Parts & Accessories

One of the most important elements of your RV is one most people will never actually see. However, if it’s missing everyone will notice.

We’re talking about RV insulation.

Nothing can make a trip unpleasant faster than sitting in an RV that’s freezing in winter or boiling in summer, thanks to substandard insulation. Good RV insulation materials will also save you money on energy costs by keeping the heat from your heater or cool air from your air conditioner from escaping.

Types of RV Interior Wall Materials

There are several different kinds of materials your RV walls can be made of. It will be up to you to decide which fits your budget and lifestyle the best.

Composite plywood

Composite plywood is made up of several different types of wood pressed together to make a large sheet of plywood that can be cut down. The inside layers are usually cheap wood, with a nice veneer over the top. It’s durable and doesn’t rip or break easily. It is, however, susceptible to water damage and if you get a roof leak, you could have damage to your walls as well.

MDF (Medium Density Fiberboard)

This is a cheaper alternative to composite plywood. MDF is made from gluing together sawdust, then pressing that between two or more sheets of wood veneer. You can then cut the wood board down to the size and shape you need. MDF is probably the most affordable option. It will be nice and light if you’re concerned about extra weight in your RV. However, in a classic case of “you get what you pay for”, MDF deteriorates very quickly. You could need to be replaced as early as one year later.


Vinyl floors and now even walls are becoming more popular as designers can now make vinyl that looks like wood or other more expensive materials. Vinyl is fast and easy to install and if you’re a DIYer, it can be a manageable project. Vinyl costs less than half the price of real plywood. It’s also easy to cut to size. You don’t need a saw or other tools, just a sharp, retractable utility knife. You can even find vinyl that is peel-and-stick making your project even easier. However, vinyl can crack and won’t last as long as more expensive materials. On the other hand, because it’s fairly cheap and easy, if you like changing out your decor this could give you the opportunity to try many different styles over the course of a few years.

RV Insulation

From how to insulate things like windows and doors to insulating RV walls, there’s a lot to know about protecting your rig. This post will help you figure out the pros and cons of each type of insulation and determine what kind might be right for you.

RV Insulation Types

When you begin researching how to insulate a motorhome, you’re going to want to concentrate on one number – the R-value of the insulation. An R-value is the official rating of the thermal resistance of your insulation. It indicates how well-insulated the camper walls are. A higher R-value indicates more thermal resistant walls. In other words, a high R-value will protect you more from hot temps in the summer and freezing cold in winter.

You’ll want to consider a few things when researching different RV insulation ideas. Of course, you’ll want to know the cost of each type of material. You’ll also want to know how long each different type of material lasts. There are some you may have to replace, and you could end up saving money with a more expensive, long-lasting insulation instead of a cheaper material you have to redo in a few years. You’ll also want to consider moisture. Some materials are more resistant than others. If you love vacationing in dry, desert, or mountain areas you may choose different camper insulation than if you often travel to humid spots.

Fiberglass RV Insulation

Fiberglass insulation is the most common type and comes standard in most motorhomes. It has a high R-value so it will offer great protection from unpleasant temperatures. It’s also easy to install and is one of the most inexpensive options.

On the other hand, fiberglass insulation wears out more quickly than some other materials and is sensitive to moisture damage. If fiberglass insulation gets wet, it expands and can lower the R-value, and it is susceptible to mold. You can plan on having to replace your fiberglass insulation every few years. It could be a good option for you if you plan to stay in a dry climate and are okay with replacing the insulation every so often.

Rigid Foam RV Insulation

Rigid foam insulation is much more resistant to moisture and has a long lifespan. It isn’t as susceptible to mold and is a great option for people who travel to many different climates or spend time in humid areas. Rigid foam insulation comes in boards of different thicknesses. It can be cut to fit any space. You install it by sliding it into the walls in sheets and fastening those sheets to the studs in the walls to prevent any airflow from outside in (and vice versa).

However, most RVs don’t come with rigid foam insulation already installed, so you’ll either need to be comfortable taking apart your walls to install it yourself, or you’ll need to hire someone to do the work for you. Rigid foam insulation is also more expensive than fiberglass. If you’re an experienced owner who travels to different climates often and is comfortable customizing your rig, it could be a great option for you, and the good news is that once it’s in, you won’t have to worry about it for a very long time.

Spray Foam Insulation

Spray foam insulation is easier to install than rigid foam insulation. To install, you load spray foam into an applicator. Spray it directly onto the walls of your RV, in the space where the rigid foam sheets would go. If you spray the foam evenly throughout the walls, it makes an airtight barrier between the inside and outside. Spray foam, like rigid foam, doesn’t come standard in motorhomes. You’ll either need to install it yourself or hire someone to do the work. This material is also very lightweight.

Spray foam has a lower R-value than some other types of insulation. It can also leave a smell that lingers for weeks or even months after it has been installed. It can be a great option for people who plan to vacation in warmer climates. Or, for RVs or trailers where weight is a serious concern.

Best Insulation for Travel Trailers

When you’re considering travel trailer insulation, you’re going to want to think about the same things as with a motorhome. Do you want to save money and go with cheaper insulation like fiberglass? Do you feel comfortable installing insulation yourself. Would you want to upgrade?

One thing to consider with a travel trailer is your tow weight. If you want to make sure your trailer stays lightweight, you may want to choose spray foam insulation since it’s a lighter option.

Best Insulation for a Motorhome

The best insulation for your motorhome mostly depends on your goals and activities when you travel. Are you okay with your RV being less insulated but more resistant to moisture? Think about whether you’re going to be traveling to many different climates or staying mostly in one. How comfortable you are with big projects like removing siding to install your insulation. (or how comfortable you are hiring someone to do it for you). Also, consider how much money you have to spend on any of those options.

As you’re shopping for your motorhome, ask about the R-value of the insulation and what type is used on the RVs you’re interested in. You may find you’re perfectly happy with the insulation of the RV you purchase without any further adjustments.

RV Insulation Price

Fiberglass insulation is likely your most inexpensive option. Especially since it comes standard in most RVs. If you’re happy with fiberglass insulation, it’s very possible you won’t have to make any modifications to your rig. Rigid foam insulation is the most expensive, but it lasts a very long time and is moisture-resistant..so while it’s an investment upfront, it may end up saving you money by not having to replace it in the future.

RV Underbelly Insulation

Skirting your RV can help protect the underbelly of your rig and keep cold air from seeping up through the floor and edges. An RV skirt is exactly what it sounds like – a giant skirt that goes around the bottom of your RV and makes a barrier between the outside and the underbelly of your RV. There are reports that RV skirts can help campers use less propane to keep their motorhomes warm. An RV skirt keeps drafts from coming into your rig from underneath your RV. RV skirts are customizable so you should be able to find a size that will fit your motorhome.

Along with using an RV skirt, you can do a little spot-insulating yourself to prevent more air leakage. You’ll need a can of aerosol foam and a flashlight. Then, climb underneath your RV to inspect the underbelly. You may find gaps where hoses and other connections enter your RV, and you can use this insulation to cover any large holes. Just be sure you don’t close the hole too tightly and put a strain on any connections.

RV Insulation for Windows and Doors

One place that tends to be drafty and can be an insulation problem is around windows and doors. You can learn how to insulate RV windows and doors much easier than installing insulation in between the walls of your RV, and it can be a good starter project if you want to begin working on your motorhome. You can keep the heat or air in by re-caulking your windows. Also, consider solar curtains and try replacing the weather stripping around the RV door.

Another option is to completely replace your windows and doors. You can shop for newer, energy-efficient windows and doors that are better at preventing airflow between the inside and outside.

Exterior RV Insulation

Besides using an RV skirt and climbing under your RV to spray aerosol insulation on any gaps where pipes or hoses enter your rig, also be sure to check your storage compartments where you can get hot or cold air entering your motorhome. Seal the doors of these compartments with weather stripping just like your RV door. Check your windows and doors to make sure you’re not allowing any outside air in while you’re looking at exterior RV insulation as well.

RV Insulation for summer tips

There are a few things you can do besides replacing the RV insulation in your walls to ensure that your RV stays cool in the summertime. Try these inexpensive tips to keep the temperature down when it’s steaming outside.

Mom, dad, and two children play corn hole/bag toss outside their parked Class C RV.

1.) Add shades

Window shades, especially solar or blackout shades, can cut down on the light in your RV and can keep the inside from heating up during the day. Draw the shades or curtains during the day to keep the inside cooler.

2.) Park in the shade

Just like you look for shady spots to park your car when it’s hot out – park your motorhome in shady spots whenever you can. In fact, a lot of campgrounds will advertise shady campsites as a way to entice you to visit.

3.) Get an RV awning

Setting up your awning not only expands the shade you have to use but can also cool the outside of your RV by keeping the sun from shining straight at your door. You could even attach material or sheets to enclose your awning and make an entire shade room. Also, consider adding small awnings outside your RV windows to add shade there as well.

4.) Pack portable fans

If you want to save some energy and avoid running your entire air conditioning, or if you’re relaxing outside under your awning but need a little breeze, portable fans can help keep you cool. You can also use the fans with the air conditioning on to keep the cool air circulating. You may also want to consider a portable air conditioning unit that comes with its own battery if you want to save your RV battery.

4.) Inspect your air conditioning

Before you head out on a trip, inspect your air conditioning to make sure it’s running properly. Make sure air filters are clean, check the fins on the condenser coils, and run your AV to make sure it’s working well before your trip.

5.) Park headed north

If you have an awning, parking north means it will block the sun from hitting your motorhome. In the afternoon and evening, your RV will make its own shadow over your seating area and keep the temps down a little.

6.) Cook outside

If you have an outdoor kitchen or grill available at your campsite, use that instead of heating up the inside of your RV. You can also plan no-cook meals of cool salads or sandwiches.

7.) Keep doors and windows closed

Try to avoid opening and closing the door to your RV so you can keep the cool air inside instead of letting it escape.

RV Insulation for winter tips

To insulate your RV for winter, you’ll want to use a few of the exterior insulating tips we discussed earlier. Here are a few ways to keep warm in winter:

Parked Class C RV on a snowy road

  • Use an RV skirt – these do take a while to install, so you may not want one for a quick 1-2 night trip, but if you’re going to be staying in cold weather for an extended time, a skirt may be worth it
  • Insulate your underbelly – climb under your RV with a can of aerosol foam and seal up any holes
  • Check your windows and doors – make sure your weatherstripping is in good shape
  • Check your storage compartments – seal those doors with weatherstripping just like your RV door
  • Check your vents – to keep warm air from escaping into your vents, you can stuff them with insulation like foam board. You can also purchase vent covers either online or at places like Home Depot. They’re also known as draft shields, and that’s exactly what they do – prevent drafts by keeping warm air from leaving your RV

RV insulation may not be a very exciting topic to discuss with friends, but it’s an essential part of a pleasant camping trip! Choosing the right RV insulation for you means you’ll be able to vacation comfortably, stay cool in summer and warm in winter and keep your energy costs and battery drain down at the same time.

For more information, take a look at how to RV in the winter.