7 Easy Ways to Improve Your RV's Insulation

It’s either too hot or too cold. Obviously, what you really want is for the temperature in your RV to be just right. Although the factory provided insulation might be sufficient for moderate temperatures, if you plan to winter in cold climates or summer in hot ones, you are likely to want to “beef it up.”

To do this, you need to increase the insulation and reduce the infiltration of cold air. There are several steps that can be taken to increase a motorhome’s barrier and improve its ability to protect you from drafts and extreme temperatures. For the purpose of this article, let’s start with the easiest and least expensive and work toward more elaborate methods.

1. Install Insulating Curtains

A quick, easy, and inexpensive way to control the temperature in your RV is to add insulating curtains. You can find these at most big box stores that offer housewares, at RV supply stores, and on eBay or Amazon. Just shop around for ones that complement your interior and provide sufficient protection. We got ours at Target.

First we bought a curtain rod and four insulating drape panels. We installed this between the cockpit and the living area. During the day, they provide an attractive framing detail. During the night (and cold winter days), we close them to trap in warm air. They also reduce our heating expenses since we are heating a smaller area and they reduce any lingering drafts from the front door.

2. Secure the Slide-outs

The second thing we noticed was the drafts coming in from around the slide-outs. In fact, after an early snowstorm in Missouri during our first winter RVing, we noticed snow on the floor next to the bed. It had blown in the gap between the slide out and the wall.

Since you can’t take permanent steps to seal those gaps (the slides still need to be able to move in and out),I found a solution that was exceptionally easy and cheap. I took a couple of pairs of my husband’s holey socks, slipped one sock within the other to get the correct width, and shoved them in the gaps on each side.

This eliminates drafts, as well as reduces the access to pests. They aren’t even noticeable unless you look very closely. Just make sure to remove them before retracting the slide-out.

3. Protect the Windows

Much of the cold air enters the motorhome through the drafty windows. In most situations, you can replace the blinds with ones that are better at keeping the outside temperatures outside. Although this can make a big difference, when you are staying in a cold environment, you will want to add more.

Insulating Blinds

When we began replacing the factory blinds with insulating, cellular blinds, we discovered this was a bit more time consuming, frustrating, and expensive than the two previous steps. First, we measured each window and were surprised that very few of them were the same size (so don’t measure one and assume that measurement applies to all of them). We weren’t sure how much of an improvement we would see from this upgrade, so we decided to replace the large windows in the living/dining room first, then go from there.

After shopping around at Lowes, Home Depot, and Menards, as well as online, we bought our first two, had them cut to size at the store, and then installed them according to the directions. We were pleasantly surprised and have since replaced the large bedroom blind with a similar-looking “black out” option. It matches the others, but keeps the sun out, which keeps the bedroom cooler in the summer. This is a work in progress, but in the long run, it will be worth it.

Insulating Plastic

Typically, RV’s have single-pane windows that do not seal very well and, although you can install a makeshift storm window by using custom cut Plexiglass secured with brackets, this can be time consuming and require seasonal installation and storage; plus, there are easier methods. Shrink film, available at home supply and hardware stores, can be applied to the insides of the windows from the comfort of your RV. This clear film can be cut to size and then attached to windows with double-sided tape and a hair dryer. Once you’ve placed the film over the window and taped it down, use the hairdryer to heat and shrink the film until it is tight.

This eliminates the cold drafts that windows usually allow in and reduces condensation on the inside of the windows. At the end of the season, just peel it off and throw it away, then use rubbing alcohol to remove the residue from the tape. It's a great, inexpensive storm window and it’s relatively easy to apply. It’s not a bad idea to leave a window in the front and back free so they can be opened on the warmer winter days to let in fresh air.

Note: Although you can buy specially produced “pillows” to insulate the ceiling vents and keep the warm air from escaping, you can easily use the same shrink film to cover them. By following the same method as you did with the windows, you can insulate them less expensively.

4. Seal the Underneath Storage Areas

The second place that cold air is likely to seep in is through the floor. Many of the underneath storage compartments have openings to the outside where gas pipes and water lines enter the rig. These need to have good weather seals, such as an aerosol expanding foam used according to the directions.

Then, use the foam, foam tape, or weather stripping to seal any gaps in the corners or around the doors. This also helps keep out pests.

Note: You can also use foam tape or weather stripping to fix any worn areas around the front door to reduce drafts.

5. Insulate the Water Hose, Faucet, and Sewer Lines

After the gaps have been sealed, it is important to protect the freshwater hose and sewer lines so they don’t freeze and crack. This can be any expensive and messy problem to fix.

The Water Hose

If you are traveling, just disconnect the hose after filling the tank. This can also be done if you are parked; you will just have to monitor the water levels and refill as needed.

If you want to remain hooked up to the water supply, you should take stronger measures. You may consider buying a heated water hose, but heat tape and insulation also work great for this. Simply take 110v heat tape and wrap it around the entire length of the hose.

Then use fiberglass or foam insulation to cover the tape. Make sure to protect the faucet and the area where the hose is connected to the motorhome. If it gets really cold, you should probably let your faucets drip throughout the night to ensure they don’t freeze.

Before we taped our hoses, we spent several mornings thawing the lines with a hairdryer, and that was even after leaving the faucets on.

The Sewer Line

It’s also important to make sure the sewer lines do not freeze. The last thing you want to do is deal with a frozen pipe in the cold. Therefore, it’s necessary to keep the hose sloping down from your RV to the campground’s sewer hookup. This ensures the flow is not hindered. Otherwise, it may freeze, creating a “plug” at the lowest spot. Another, more permanent solution that’s more likely to withstand the cold is to replace the plastic hose with a thin-wall PVC sewer pipe along with its connectors for the sewer hookup. This method is easy and inexpensive.

6. Winterize Water and Waste Tanks

Just as the infiltration of cold air makes the interior temperature of your motorhome plummet, having cold or freezing conditions in your fresh water and holding tanks can also affect how warm your rig is. You can improve this by merely draining the fresh tank and keeping the valves of the other tanks closed unless you are dumping. If you plan to spend a considerable amount of time in colder temperatures, you may need to further protect the tanks to keep them from freezing.

One options is to add large amounts of RV antifreeze to the tanks; just don’t drink the water. Another option is to build a fairly elaborate insulating box of plywood and fiberglass around the tanks with a light bulb as a heat source. Although this is reportedly effective, it is difficult for most people, so I don’t recommend it.

With enclosed tanks, heating the area with a space heater with a thermostat and safety features, designed for use in storage set on a low setting or a heating pad made for use in motorhome holding tanks is an easy solution. These can usually be found at RV supply stores like Camping World or on Amazon. This is what we did.

7. Additional Insulation Behind Cabinets

This is by far the most elaborate and time-consuming aspect of improving the insulation of your RV. Those dedicated to reducing heating and cooling costs typically undertake this project, as well as those who prefer living in extreme climates. Fortunately, you don’t have to do this all at once; it can be a work in progress. Just keep in mind that every little bit helps.

There are several different ways you can do this depending on how much you want to spend, how much effort you want to put in, and how “finished” you want the end product to appear. Depending on which method you choose to use, you will need a combination of the following supplies:

Tape measure
Utility Knife
Form of insulation
Particleboard or Carpet
Double-sided carpet tape, insulating tape, 3M spray adhesive, or liquid nails

Start with your largest cabinet. In our case, that was the wardrobe. Use a tape measure to determine the dimensions — height and width — of the back wall, then write them down. Following these proportions, measure and cut the insulation and the particle board or carpet to fit, and install. Then, merely repeat the process for each cabinet and closet.

Fiberglass Insulation If you choose to use fiberglass, you will want to put down a drop cloth to collect any stray fibers. Otherwise, you may still be finding them months later. Use the utility knife to cut the insulation and use insulating tape to affix it — paper side to the wall, fiberglass toward you — to the back wall. Then install the particleboard in front of it, using spray adhesive or double-sided carpet tape to fix it in place. (The lumber departments of most home improvement stores like Lowes and Home Depot will cut particleboard for a small fee, or you can measure and cut it yourself.) You can leave it roughed in like this or further secure it by covering it with carpet (affixed with either the liquid nails or the double-sided carpet tape) for a factory look.

R5 Pink Board Insulation

This is an easier method than using fiberglass insulation. Just use a utility knife to cut the pink board and then adhere it to the back wall of the wardrobe with insulating tape. Then use spray adhesive, liquid nails, or double-sided carpet tape to add carpet. Covering it with carpet not only looks better, but it also adds a second layer of insulation.

Styrofoam Insulation Using Styrofoam to insulate your cabinets is the cheapest method and it’s easy, as well.

Cut the Styrofoam to fit the space, then tape it in place with the insulating tape. Keep in mind that Styrofoam isn’t as malleable as other methods. So, for spaces that are rounded, you may need to cobble together a few pieces or use spray foam to fill in any gaps. Then cover the surface with carpet, fixing it in place with double-sided carpet tape or spray adhesive.

In Conclusion

Improving the insulation in an RV serves several purposes. It keeps the desirable temperature inside and the undesirable temperature outside. It reduces the expense of heating or cooling the interior. Also, it decreases the chance of bugs or rodents infiltrating your home on wheels and causing damage or mischief.

As you can see, there are several ways to make your space more secure, some much easier and cheaper than others. How much additional protection you should install depends on the type of motorhome or trailer you have and what type of environments you frequent. For moderate temperatures, adding insulating curtains and blinds, and then blocking the spaces around the slide-outs may be all you need. If you find yourself in colder temperatures, however, you should seal the windows and protect your water lines, hoses, and tanks. For those who permanently live in inhospitable environments, fully winterizing and insulating the RV is a virtual necessity.

These measures require an initial investment of time and money, but are usually worth it. They ultimately save money, discomfort, and the frustration of repairing or replacing parts that have become damaged from the cold.

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