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RV Insulation 101: A Complete Guide on RV Temperature Control

Updated: Nov 22, 2023

Learn how to insulate an RV, the best insulation materials for travel trailers, and tips on controlling the temperature inside your motorhome.

best insulated RV trailers

RV insulation is often an overlooked aspect when you go out shopping for a new rig. Standard motorhome insulation depends on the model, type, and manufacturer of RV. But more often than not, factory insulation falls short in keeping your rig cool in summer and warm in winter. Read on to learn how to insulate your RV so that you can control the temperature inside your rig year-round.

Table of Contents

What is R-Value Insulation and How Does it Affect Your RV?

R-Value is a measurement of a material's thermal resistance. It measures the ability of heat to transfer from one side of the material to the other. The greater the R-Value of a material, the greater its thermal resistance or its insulation effectiveness. For example, the R-Value of one inch of solid wood is 1 while a blown fiber-glass wall made of the same thickness has an R-Value of 3.7 to 4.3.

R-value insulation
Table of Insulation R-Values Winnebago Revel

When calculating the R-Value insulation you need for your RV, you need to consider a number of factors:

  • Your geographical location and weather

  • The type of heating and cooling systems installed in your RV

  • The insulation system

For example, if you're headed out for winter camping and are relying on electric space heaters to keep your RV warm, you will need an R-Value of at least 10 in the walls and 20 in the ceiling. The type of insulating material you choose will also determine the R-Value of your camper, generally, RV manufacturers use a combination of wood and/or fiberglass to insulate an RV. So if the R-Value of a camper is 12, that may be the total value of the insulation system.

R-Value is important to learn how much and what kind of insulation you need for your RV. For example, if you camp long-term in an area that doesn't get extreme temperatures, you can easily get away with R-Value insulation of 7.5 to 10 (the value will vary based on the size of your RV).

Types of RV Insulation

The total R-Value of your RV insulation will depend on the materials you use for insulating your motorhome. Here is a list of the common types of RV insulation you will find in the market.

  • Fiberglass

  • Rigid Foam

  • Spray Foam

RV Fiberglass Insulation

Fiberglass insulation has a high R-Value which is why it is considered the best insulating material for extreme temperatures. Most manufacturers use fiberglass insulation in RVs and you are more likely to find both Class A motorhomes and smaller campers with fiberglass insulation. Fiberglass is cheaper as compared to other insulating materials which makes it a popular choice for DIY RV insulation as well. However, fiberglass tends to expand as moisture makes its way into it, decreasing its insulation properties and its total lifespan.

blown fiberglass RV insulation

The moisture can also make the insulation a hotbed for mold to grow which in turn is dangerous if left unattended. This is the reason why fiberglass insulation is not recommended for RVers who plan to travel to areas with differing extreme temperatures frequently. The change in weather expedites the moisture build-up in fiberglass insulation making it ineffective.

RV Foam Board Insulation

Rigid foam is a type of foam insulation that although has a lower R-Value, can last for ages without declining in quality. You can find rigid foams of various thicknesses in the market. They are usually available as boards that you can cut and install inside the walls and roof of your RV as sheets. RV manufacturers don't use rigid foam for insulation so if you want to install it you either have to take your RV to professionals or DIY it. You can do so by using a can of caulk gun and industrial tape to tightly fit the foam into the studs on the wall to avoid airflow.

rigid foam insulation for RV

Rigid foam isn't easy to install and custom installation can be expensive. However, for RVers who plan on camping in areas with extreme weather, it is the only type of insulation that can help them control the temperature inside their motorhome.

RV Spray Foam Insulation

Spray foam is another type of foam insulation that can be used for temperature control in an RV. It has the same R-Value as rigid foam but it is lighter in weight and easier to install. The foam can be loaded into an applicator and sprayed on the walls of the RV to insulate it. An evenly distributed layer of spray foam bonds tightly together with itself to create an airtight barrier for temperature, moisture, and even some noise.

spray foam insulation for RV

Spray foam provides ultra-lightweight insulation that isn't meant to keep extreme heat or cold outside. This means it isn't for RVers who want to camp in areas with extreme temperatures.

Cost of RV Insulation

The total cost of RV insulation depends on a number of factors including the type of insulating material you choose, the amount of insulation you need, and how you install it. Fiberglass RV insulation is the cheapest while rigid foam RV insulation is the most expensive. Any custom RV insulation will cost you more than if you DIY it. For example, a DIY spray foam insulation on a campervan can cost as much as $400, more if you hire a professional to do it for you. Layering RV insulation is more expensive than choosing a single type of insulation material.

How to Choose the Right Insulation for Your Rig

Now that you know all about the R-Value of insulation and the types of insulating materials used in an RV you can make an educated decision as to what is the best insulation for your RV. Here is a table to help you make your decision.

​Type of Insulation




​Choose If



  • ​High R-Value

  • Easy to Install

  • Cheap

  • ​Lower lifespan

  • Not moisture-resistant

​You don't travel often and camp at areas with moderate temperature

Rigid Foam


  • ​Durable

  • Moisture-resistant

  • Resistant to high temperatures

  • ​Difficult to install

  • Mid-low R-Value

  • Expensive

​You travel in areas with extreme climates

Spray Foam

Moderately Expensive

  • ​Lightweight

  • Moisture-resistant

  • Less Expensive

  • ​Installation takes practice

  • Low R-Value

  • Professional installation is expensive

​You travel in areas of moderate climate in a lightweight RV or camper

How to Insulate Your RV

Insulating your motorhome can be a tricky task if you don't know what you're doing. However, with research and practice, you can learn how and where to reinforce your RV insulation so you can keep it warm or cold.

RV Window and Door Insulation

To insulate your RV for temperature control you first have to consider the areas of your RV that are most susceptible to temperature changes; the main inlets (and outlets) of your motorhome. The doors, windows, vents, and skylight of your RV are the first things you need to insulate for keeping your rig cold or warm.

RV window insulation

If you want to keep your rig warmer, start by covering all the areas in your RV that can let the cold wind in; use foam inserts around your RV door to insulate it completely, use spray foam to seal the cracks and holes in the RV, cover all vents with RV vent insulator, use an RV skylight insulator to cover the large skylight, and get insulated RV curtains for the windows. You can also use an RV door window shade that works to keep the RV warm in winter and provide RV window insulation for summer as well.

RV Roof and Floor Insulation

The roof of your RV carries the weight of your RV insulation. Most RVs have roofs that are made of PVC and then reinforced with fiberglass insulation with an R-Value of 10 and above. You can add an additional layer of insulation to the roof to protect your rig from extreme temperatures or replace the factory insulation and install your own. RV floor insulation can do wonders for controlling the temperature in your RV. Something as simple as using RV rugs can help you keep the rig warm in cool weather.

campervan roof insulation

RV Walls and Side Insulation

Insulating RV walls is as important as insulating the roof. Generally, any custom RV insulation focuses primarily on wall and roof insulation. The best insulation for RV walls is the one that can handle the temperatures of where you are camping and stands the test of time. RV slide insulation is also important to make sure your rig doesn't get too hot or cold.

campervan wall insulation

RV Plumbing System Insulation

Your RV plumbing system is the most susceptible to weather changes. Extreme cold can make the RV pipes and holding tanks freeze and get damaged. Most RVers empty their holding tanks and pipes when traveling to places with very low temperatures. You can also invest in holding tank insulation and insulated water hose for RV to keep using your RV plumbing system easily.

RV pipe insulation

RV Underbelly Insulation

When insulation your RV, don't forget the underbelly. Adding insulation to RV underbelly can be as simple as installing an insulated RV skirting to the motorhome. You can choose from a number of different materials for RV skirting ranging from weather-resistant skirtings to foam boarding, and plywood skirting. If you plan on long-term camping you can install a permanent RV skirting on your rig to protect the underbelly.

RV underbelly insulation

RV Engine and Generator Insulation

Last but not the least, protect the RV engine and your RV generator from getting affected by harsh weather by insulating both. RV engine insulation can take many forms; you can use an RV engine insulation cover to protect the engine from the weather when your rig is parked. Regular maintenance and check-ups can also keep your engine working efficiently.

RV engine insulation

Tips for Keeping Your RV Cool in the Summer

While RV insulation is the best way to keep your motorhome cool in the hot weather, here are some additional tips to help you keep the heat at bay.

  • Use Sunshades: RV window sunshades can help keep both sunlight and heat from the sun out of your motorhome. Invest in sunshades that provide total blackout and a snug fit so you can get the most out of them.

  • Park in the Shade: This goes without saying but parking in the shade can help you keep your RV cool in the summer. Choose a spot that gets very little to no sun.

  • Proper Ventilation is Key: Keep the doors and windows of your RV open during the early morning and evening hours to keep your RV cool without having to run the AC. This can help you keep your travel trailer cool even if you're boondocking and not hooked up to electricity.

  • Get an RV Awning: Setting up an RV awning can give you the shade you need. A lot of RV parks and campgrounds don't have shaded areas for parking, an RV awning can give you that much-needed reprieve from the sun.

  • Park Facing North: Park your rig facing north so you don't get the brunt of the sun. The awning can protect you from the rising sun and the shade from your rig can help keep you cool as the sun sets.

  • Invest in Portable Fans: You can find portable fans that work on electricity or batteries and use them to keep cool during the summer. This helps save you both power and fuel.

Tips for Keeping Your RV Warm in the Winter

Most RVers will agree that it is easier to keep your motorhome cool than it is to keep it warm, especially if you're parked in areas that have extreme winters. Insulation helps a lot but here are some additional tips to keep warm in the winter.

  • Use an RV Skirting: Protect the underbelly of your rig by installing an RV skirting. This will keep the cool winds at bay, protect RV plumbing, and boost your heating efforts.

  • Space Heaters Help: The best thing about space heaters is that they are light and don't take much space. You can place multiple space heaters around your travel trailer to keep warm.

  • Electric Blankets Keep you Cozy: If you own a small campervan then a good electric blanket is likely all you'll need to bear the cold. Easy to carry and more energy-efficient than running your RV heater.

  • Cook Inside: Your RV kitchen can double as a heating system if you cook inside your RV. The heat from the stovetop and appliances can make your rig nice and toasty.

  • Layer Winterwear: Layering the right clothes can help you stay warm in your motorhome. You can't run heaters all day long so wearing the right winter clothes can keep you warm.

  • Keep the Doors Closed: Proper insulation can keep cold winds at bay but an open door won't. Try to use your rig's door as little as possible and keep it closed so that the heat stays inside and the cold stays out.

What is the Best RV Insulation?

There might not be a universal best RV insulation but we have some recommendations based on the different types of RVs in the market.

insulating RV for winter

Best Motorhome Insulation

Motorhomes vary in size and weight. If you own a Class A motorhome then it will already come with fiberglass insulation in the walls and roof. If you plan to stay put in areas with temperate climates then you don't need to install additional insulation. But if you want to hit areas that are extremely hot or cold then invest in foam board insulation.

Best Travel Trailer Insulation

Travel trailers usually require additional insulation as they have to take the brunt of weather changes. Apart from R-Value, another important thing to consider when choosing the best travel trailer insulation material is the weight. Because travel trailers have to be towed you can't line them with heavy insulation as that would add to their tow weight. Foam spray insulation is the best option for travel trailers. If you want to travel to areas with extreme weather then consider layering foam and fiberglass for added protection.

Best Insulation for Camper Van

There are many insulation options when it comes to camper vans. Since they are smaller in size and more compact it is easier to experiment with different insulation materials. For temperate weather travel, you can opt for fiberglass, sprag foam, and thermal wrap. When traveling to areas with colder weather you can insulate your pop-up camper with earth wool, sheep's wool, or rigid foam insulators.

The Last Word

Learning about RV insulation is important if you want to truly manage the temperature inside your RV. A little preparation can help make your RV camping trips safe and fun. When it comes to RV insulation always consult a professional before you attempt any DIY project. Make sure you understand what your requirements really are before committing to any project.


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