Insulating a Trailer: Your One-Stop Guide

Planning to live in a mobile home, a trailer, or an RV for longer periods should put good insulation on your list of priorities. When the walls are thin as they are on those homes, the heat is transferred easily in and out of the trailer, making the winters unbearably cold, and summers awfully hot.


If you used to make only short summer camping trips in your trailer in the past, you could have easily overlooked the need for insulation. However, when a trailer turns into your new moving home, missing to insulate it properly may become something you’ll regret when the weather gets harsh.


Most of the trailers and mobile homes are already built with some kind of insulation, but if you are planning to spend more time living in such space, you should consider investing in a good one that will make your life comfortable, and above all – safe.

Why Is Insulation Important and How Does It Work?


The indoor temperature of your camper will always very much depend on the temperature outside. Heat transfer happens with the laws of physics as the warm air tends to penetrate a cooler space.


Whether you’d be trying to keep your trailer warm or cool, the proper insulation will play a vital role in making that project successful.


When the sun radiates heat onto the roof of your trailer, it will make it hot inside, and the other way around, if it’s cold outside, the warm air from the trailer will tend to flow out. Heat can also get transferred from one material to the other. So, if it’s hot outside, you will try to prevent the sun from heating the air inside of your trailer by warming up the walls and the roof.


That’s where insulation comes in. It is much better to prevent the heat from coming in than using fans and air conditioners to cool your camper. That works the same for the cold. When it’s cold outside and you want to keep your trailer warm, you would rather prevent the heat from getting out than use heating more than necessary.


For that matter, you would need good insulation that would slow down if not stop the heat transfer. It’s quite simple, the thicker the insulation material on your walls is, the longer it will take for the heat to pass through it and leave your trailer.


The material insulation is made of, and its quality can make a big difference, too. That’s why it’s important to find the best one to fit your needs in the camper you’ll be spending the nights in. The quality of an insulation material is usually measured by an R-value that shows how well it can prevent heat transfer. R-value is marked with numbers, and the higher number it has, the better the insulation.

Is It Difficult to Insulate Trailers?


Trailers differ from regular houses in their weight, thinner walls, and the fact they are not attached to the ground. All of these features are great for mobility, but not so good for keeping the inside temperature warm or cool enough.


Thin walls, windows, and doors, as well as the space below the trailer, allow the heat to flow in and out more easily which can be a challenge when looking for proper insulation for your mobile home.


There are several options for insulating a trailer, and some of them are easy to install, even by yourself, while some others could require special equipment and professional help. The difference could be in their quality and longevity, however, good options are possible to find on both sides.

What Kinds of Insulation Can Be Good for Your Trailer?

Several types of insulation could work very well on trailers, so it depends on people’s preferences.


  • One of the most common materials used for insulating trailers is a rigid board. It is quite cheap and easy to find and install. But if you don’t seal the walls perfectly, watch out for possible moisture and mold.
  • Spray foam is another common insulation for mobile homes and trailers. Although the opinions are divided, it is still very popular. One of the best things about spray foam is that it has a very high R-value, and makes the walls hard and firm. It’s water-resistant and can fill out any cracks or holes.

    However, some materials won’t react well to the spray foam, especially metal, and aluminum. It may look easy to handle when applying it, but maybe you should consider getting professional help, as it can get very messy, and you’ll need some experience with the material and how much it expands when it dries.
  • Maybe the most common insulation for homes is fiberglass, still, it is just not the best for trailers and campers as it can get damp and grow mold that can harm your health. Despite those facts, many people are still using it because it’s very affordable, but we would rather recommend considering other available options.
  • A better version of blanket insulation is rock wool. Similarly to fiberglass, it comes in sheets and is made of mineral fiber based on basalt rock and recycled slag. It has a fine R-value and is water-resistant. A material that doesn’t support any moisture is crucial for mobile homes as they are exposed to it much more than regular houses. Another advantage of rock wool on trailers is its sound insulation property.

    Rock wool and fiberglass could be dangerous to touch, so you should be extra careful when installing it, or look for professional help. These insulation methods can also be a bit more expensive.
  • You might have heard of bubble insulation, but that one just wouldn’t be a great choice for insulating the walls of a trailer. In this setting, maybe you could use it only as a window cover, but nothing more than that.
  • At first glance similar reflective insulation rolls, but a much better option comes with Prodex Total which is made of cell polyethylene foam and covered with reflective reinforced foil.

    This insulation comes with a great R-value and is able to prevent moisture, condensation, mold, pests, and any airflow. When insulating a trailer, choose Prodex Total 5m or 10m, and apply it by using a double-sided tape for the best results.

What Else Can You Fix on Your Trailer?

Before you think you are done with insulating your camper, make sure you've gone through all the details and prepared your mobile home properly.


Indoor Insulation


Check the inside of your trailer for any damages, leaks, holes, or seams that need to be fixed. The main points that could need some special insulation are:


  • Windows
  • Doors
  • Ceilings
  • Floors

Windows are the most sensitive parts of your mobile home, van, or trailer. They are often made light and thin, which means they could transmit heat easily and allow the air to flow through seams and cracks around their frames.


Some better RVs have double-pane windows, which may give you an idea of replacing yours with something similar. That isn’t a bad idea, but it could be a very expensive option. Besides, considering the fact that not all trailers could hold such windows due to road vibrations, that may be a risky solution, as well.


A better and cheaper option could be to use solar or insulated curtains, or bubble wrap and bubble insulation that can be attached to the windows with velcro or tape. Most of these will do very well to stop the draft and some of the curtains will even be made to let in a lot of natural light.


Doors can be problematic as much as the windows. Make sure they have good weather stripping, otherwise, use a door snake or a thermal curtain to cover it. This works for the entrance door on your trailer, but also on the storage compartments and back of the cabinets.


If you’re planning to travel or spend time living in your trailer where the weather is very cold, draft and moisture will be some of your biggest enemies. Not only that by insulating your door you’ll be protecting yourself from cold, but you will also be saving your trailer from damage that comes with water and snow.


Even after insulating the walls and ceilings of your trailer, don’t forget about the vents. You can use a vent cover to insulate that part but stay cautious, especially when cooking and using gas.


Even though your floor may already be insulated, a couple of rugs or small carpets will help keep your feet warm in the trailer during the winter.


Outdoor Insulation


Use skirting when you are planning to stay parked on the spot with your trailer, especially in cold weather conditions. Skirting considers placing a plastic sheeting around your trailer, van, or mobile home, that covers and insulates the bottom of it and looks like a skirt.


This type of insulation can do wonders and stop a significant amount of air from cooling the floor and the pipes of your mobile home. It is often custom-made for each trailer or van, but you can also make it on your own from plastic sheets, plywood, or boards.


Skirting should be installed and removed quickly and easily using buttons or snaps, especially if you are often on the move, but if you are planning to keep your trailer on the spot for some time, you can combine other insulation with it by placing foam board behind the skirting, for example.


Skirting can protect the pipes under your mobile home as well, but only to some extent. If you’re living in a trailer where it’s really cold outside, make sure to insulate your water and sewer pipes, too.


Those who are used to camping in cold weather conditions know that covering your trailer with an insulated tarp could be of great help, too. It could keep the roof dry and prevent freezing. Still, if covering the trailer roof, don’t forget the ventilation which is crucial for your safety, and will prevent condensation, and mold.

Some Useful Tips and Ideas

Against the Cold


If you are not into spending money and investing in some big insulation work but are still ready for a winter adventure, here are some other ideas that could keep you warm in a trailer:


  • Use portable heaters, they are cheap, easy to move, and very convenient for heating small spaces.
  • Insulate your bed. An additional foam board under the bed or a memory foam top mattress will keep you warm on a cold night. Thermal sleeping bags and electric blankets are very useful, too.
  • Cooking and baking are great winter activities! Not only is it cozy and delightful, but it will make your camper warmer. However, stay alert, and keep your vents open while cooking, especially if you are using gas.

Against the Heat


Camping sounds much less extreme as a summer activity. Still, staying in a boiling hot trailer is something you’d definitely like to avoid.


  • Make sure you keep your trailer in the shade, at least for the hottest part of the day. Keeping your camper exposed to the direct sun isn’t good for you or any food, things, or appliances that you are keeping inside of it.
  • Use fans to move the air and cool your trailer. Your trailer will inevitably get hot in the summer, but keeping it in the shade and cooling it with fans will at least allow you to sleep comfortably inside at night.
  • Cook outdoors. Summer is perfect for cooking and dining outside, and it will keep the extra heat out of your trailer.
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