RV insulation

RV Insulation: Tricks for a More Comfortable Living Environment

Share on Facebook Share on Twitter Share on Pinterest

Keeping your RV cool in the summer is becoming more of a concern as we see record-breaking temperatures. Even in the Snowbelt states, there are weather reports that show temperatures close to 100° Fahrenheit in July and August. With the full-time RV lifestyle increasing, keeping your RV cool in extreme heat in the Sunbelt states isn’t a comfort issue; it’s a life-threatening problem.

Your RV’s insulation is your first line of defense in protecting you from outside temperatures. It contains your inside climate-controlled air. RVs are not built like airtight fortresses; they can only withstand so much.

Our feature article will discuss RV insulation for the summer. We’ll explore how insulation works, what common insulations manufacturers use, and the benefits of each. To help you with your travels, we’ll show you some of the best ways to insulate your RV for summer with tricks veteran RVers use to make your RV a more comfortable living environment.

Insulation Basics

RV Insulation: Tricks for a More Comfortable Living Environment


Everyone knows the value of insulation, but most don’t know how it works. The basic concept is to use a material that prevents heat from flowing through it. Builders place this nonconductive material between the outer and inner walls of a structure (in this case, your RV).

Insulations have different levels. Each type of material has a rating called an R-Value (R stands for “resistance”). The R-value is the unit of measurement used to determine the level of thermal (heat) resistance an insulating material has.

For example, air is a natural insulator. A four-inch space between two building materials has an R-value of 1. While this isn’t a lot, it’s better than drywall, concrete, or stone.

A metal door with polystyrene foam insulation that’s two inches thick has an R-value up to 11. This negates the heat conduction of the exterior metal of the door and the outside temperature. Assuming the door has the proper seal, this entryway is airtight against any heat leakage.

RV insulation in underbelly: Did you know that most new RVs in 2020 have insulated sealed underbellies? This increases the R-value of the RV insulation floor to allow for camping in colder and hotter temperatures.

This feature used to an option, or standard on all-weather coaches. Due to its popularity, it’s now showing up as a standard feature. You’ll also see other insulating features on RVs for late-season camping.

Common Insulators in RVs

Common Insulators in RVs

There are three common types of insulation used in today’s RV construction. Block foam, fiberglass rolls, and spray foam. Block foam is most often used.

RVs have similar R-values to traditional homes. Sidewalls can be between 5-10 and ceilings go as high as 20. The most common rating for sidewalls is R7 insulation in RVs.

Sidewalls have compound R-values: RVs with Azdel shells are popular for those living the RV lifestyle in harsher climates. One of the appeals of Azdel is its sound and thermal insulating attributes.

There are many parent and subsidiary manufacturers that use Azdel in their RVs. Some include: Forest River, Lance, Jayco, Nexus, Heartland, and Winnebago. When used in combination with the insulation, it increased the R-value of the sidewalls.

  • Block Foam: Block foam is the preferred insulator for RVs for many reasons. It can be cut to size to fit any configuration. The foams used can withstand high levels of heat during the laminating process.

    Some use polyurethane, while others use polystyrene. The versions RV makers use vary in thickness, R-value, and other specifications. The chemical makeups of these foams are different from that store brand cooler, and most are environmentally-friendly.

    For RVers, you’ll enjoy the fact that it’s resistant to moisture, mold, and other factors. Block foams will last beyond the life of your coach, so you don’t have to worry about replacing it even if you’re the third owner. Block foams do come in various R-values; as a tip, do your research to see which level the RV you want has.

    If you’re building your own RV or rebuilding one, block foam has a high cost and is difficult to install. Do your homework and try some practice runs on some scraps to figure out how to install it. Do some research into the different types to learn which material is best for you.

  • Fiberglass: If you’ve ever replaced the insulation in your house, then you’re familiar with fiberglass insulation. RV fiberglass insulation exists in older coaches and uses fiberglass rolls throughout. New models don’t use it because of its weakness to moisture.

    Fiberglass is cheap and easy to install. When it’s exposed to moisture, it expands and loses its effectiveness. Both mold and rodents find it a great environment to nest in.

    If you’re going to use this material in your D.I.Y. project, make sure your interior walls are easy to take down. It’s required to replace fiberglass insulation every couple of years. As you travel through the various climates, you have to assume the humidity will make its way through.

  • Spray Foam: Spray foam is a low-cost option that can create an airtight seal. As you spray it in, it expands during the drying process, finding all those nooks and crannies other insulations can’t cover. If you decide on this method, make sure you use protective gear to avoid fumes and it spraying on your clothes.

    Spray foam is a great middle-of-the-road insulator. If your camping trips include more of the temperate regions of the country, you’ll be fine. If you’re concerned about how to keep cool in Arizona or stay warm in northern Minnesota, this insulator won’t be able to handle those temperature levels.

    This type of foam is moisture repellent and very lightweight. It’s long-lasting, so this project should be a one-and-done undertaking. Make sure you keep the windows and vents open for about a week or so because it’ll take a while to air out the fumes.
LINGDA 21.53 SqFT 10mm Heat Shield Thermal Sound Insulation Proofing Deadener Mat Car...
  • 100% Brand New heat shield Car Sound Deadener, PE with aluminum...
  • Strong sound deadener,sound insulation and absorption...
  • Scratch resistant. The surface high-fiber cloth is fiberglass....
  • The fire proofing grade with the mat is B2 and its distortion...
  • Applications: Exterior bulkhead, firewall, hood, engine...

Is there space in my sidewalls to add more insulation?: In current RVs, manufactures seal the sidewall layers together through a heat pressure process and then laminate it. If you were to cut a wall open, you’d see its pretty tight. Designers don’t build today’s RVs to allow for space within the walls beyond the wiring and plumbing.

Techniques Veteran RVers Use to Beat the Summer Heat

RVs have many different components. Your insulation holds in most of your interior temperature, but there are many places for air to escape and heat to come in. Many in the RV community use the tips below as inexpensive mods for keeping cool in the summer heat.

Important to off-griders: For those that rely on solar panels for electricity, these tips are most important. If you read our discussion about running your A/C off solar power, you’ll learn that your air conditioner eats up your battery power. Keeping your RV thoroughly insulated and using these tips can save you critical amp-hours.

Maintenance Tips for Beating the Heat

Windows and Doors

Maintenance tips for RV window
  • Windshield covers for motorhomes: Using a windshield cover on your motorhome can decrease the inside temperatures by 10 degrees or more. Another option is cutting a roll of reflective bubble foil that stretches across the inside of the glass. There are companies that can custom make these for your individual motorcoach.
  • Insulating your windows and doors: Combining reflective material with block foam, or using block foam with a reflective coating can further insulate your windows. Windows are the number one culprit of heat leakage in your RV. Using these two insulators together will keep the heat from the sun out and keep your A/C in.

Reflective bubble wrap insulation: A fairly new development in window insulation is a reflective bubble wrap material. Companies like Reflectix, make rolls of this insulator that you can cut to size.

Attaching a sheet of this material across your windows can solve your UV issues. This insulator is inexpensive and only requires double stick tape and a pair of scissors. If it gets damaged, replacing requires cutting another sheet from the roll you have in your storage bay.

  • Add tinting to your windows: Tinting your windows can add privacy to your RV. It also reduces UV penetration through your windows. There are tinting films you buy that can be cut to size.

    If you decide to do this, there are a few things to keep in mind. RV and car windows use different materials, so don’t use RV tinting film on your passenger vehicle. Avoid placing the tint on your motorhome windshield or other windows that don’t comply with state and federal transportation laws.

  • Add blackout shades to your windows: Another choice for blocking the UV heat are blackout shades. RV manufacturers are adding electronic blackout shades as a factory feature on motorhomes and upper-end towables. If your coach doesn’t have them, they are available to purchase in the manual versions or electronic version on Amazon.
  • Block roof vents: Roof vents that have fans can help create a wind tunnel in your RV by venting out the inside air. They can be a double-bladed sword because sun heat can still come through. To better trap your A/C temperature inside, you’ll want to insulate the vent with something like the Camco RV Vent Insulator or something comparable.
  • Cover shower skylights: Most RVs create headspace in the shower by placing a skylight in the ceiling above it. While this makes the shower less claustrophobic, its a major heat source in the summer. Replacing it with a tinted version, or adding a removable reflective cover can decrease your RV’s temperatures significantly.

    Another option is replacing your existing skylight with a tinted one. You can find tinted versions that are measured specifically to your brand of RV or in similar dimensions. This is an uncomplicated project if you want to do the work yourself.

Seal and Insulation Inspection

  • Recondition or Reseal your weather stripping: Rubber weatherstripping creates a seal around your windows, slideouts, and exterior bays. Using a silicone-based rubber seal conditioner will keep the stripping pliable and efficient longer. Once it becomes dry or shrinks, its time to replace it.

    The sun, rain, and temperature changes affect the rubber. The stripping loses its pliability over time and starts to create gaps where air can leak. Replacing weatherstripping is a lower level do-it-yourself project most people can complete.

  • Recaulk your roof, sidewalls, and other sections: You want to inspect to caulking around the seams of your towable and drivable RV. If the factory didn’t use silicone-based caulking, heat exposure can break it down over time. These potential gaps will let air out and moisture in.

    Silicone-based caulking is the optimal substance to use. Ultraviolet radiation and temperature don’t affect it. It’s also resistant to mold, mildew, and other growths.

  • Reinsulate the walls: If you have an older RV, or aren’t happy with the insulation you have, reinsulating your walls may be a consideration. There are a number of choices you can choose from, as we mentioned above. Before you get started, make sure you know how your sidewalls are constructed to determine how in-depth the job is going to be.
  • Inspect your air conditioners and refrigerator vents: Both your A/C and your refrigerator vents can become blocked up due to debris. A quick solution is to take a wet/dry vacuum with a hose extension to them. Make sure you are keeping up with the recommended air filter replacement the A/C manufacturer discusses.

Simple Strategies to Lower Temperatures

These next set of strategies are simple solutions people overlook. Experienced RVers have found them to be reliable enough to use regularly to decrease interior RV temperatures. Using some of these can also help your A/C from having to work hard to maintain temperature levels.

  • Block slideout edges: Even with good weatherstripping, slideout edges can still let air out. Door snakes are normally used at the bottom of a door to stop drafts from coming in during the winter. Using them around your slideout can give you that extra layer of insulation from temperature loss.
  • RV skirting: RV skirting is primarily used during winter to keep the cold (and critters) from getting under your RV. It’s also a great way to keep the summer heat from getting in as well. The skirting creates a shaded area under your coach that reduces conducted heat from cement or other ground materials from coming through.
  • Switch to LED lights: Incandescent bulbs radiate enough heat where it can make a difference. If they’re close enough to your temperature control sensor, they can turn on your A/C needlessly. Switching to LEDs not only reduces heat but also reduces your RV’s electric usage.
  • Cook outside: Using your stove and oven inside your RV can quickly heat things up. Preparing your meals outside can prevent this from happening. Using a barbecue or outdoor kitchen on your RV is a great option.

    Outdoor kitchens are becoming a popular feature in almost every class of RV. Many RV manufacturers are offering this feature in their 2020 line ups. Check out our feature article on outdoor kitchens to further explore them.

  • Use fans: Designers develop RVs to allow wind to flow through the coach from one end to the other. Ideally, when you have your windows open, if you catch the breeze right, it will blow through the coach. Placing portable fans throughout your RV will move the air around more efficiently.

    This will cool things down faster and create less of a strain on your A/C. Ceiling fans in fifth wheels help with this too. Fans also help moving heat around in winter

  • Keep your city water hose off the ground: During the summer, your RV’s cold water can be hot. This occurs because your city water hose is laying on the ground. Propping it off the ground will prevent it from heating up due to the heat radiating from the ground.
  • Keep your heat vents closed: Keeping your furnace vent opening closed will help cool things down faster. Having the vents closed keeps the internal air inside the living space. Cooling your furnace ducting isn’t necessary.
  • Park strategically: If you park your RV facing north, you can reduce direct heat from the sun. In the United States, the sun is in our southern sky. If you don’t have rear windows, you won’t have the sun shining on a window all day.
  • Park in a shaded area: Trees and other covers can keep your RV cool. Parking in a shaded area will decrease the direct sunlight to your RV. This is a quick solution on how to shade your RV.
  • Go North: During the summer, heading to the northern states or Canada is the best time of year. Temperatures are less intense and you can experience environments not seen in the sunbelt states. If you can’t go that far, heading to the mountains can be just a trip of a lifetime as well.

What About Winter?

Many RV insulation for winter tips and techniques are the same as our summer discussion above. The concept is the same; keeping the inside temperature contained as best possible. If you maintain your RV properly, you’re eliminating many of these potential issues.

Inspect your RV’s seals, weatherstripping, and other components on a regular schedule. Keep up with the preventive maintenance. Talk with other RVers you come across and learn what they do to keep cool to beat the summer heat.

Product data was last updated on 2021-02-28 at 00:59.