How to Make Camper Skirting Out of Foam Board Insulation

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One of the winters we spent living in our fifth wheel (a four-season, 38-foot 2009 Keystone Everest) we stayed in a mobile home park that did not allow us to use the vinyl skirting we had previously made from billboard tarp material, so we made foam insulation board RV skirting instead.

The project was actually easier and cheaper than our DIY vinyl skirting, and we really liked how it ended up looking.  If you’re looking for the cheapest and easiest way to skirt your trailer or motorhome yourself, especially if you plan to stay in one place for a while, I would definitely recommend considering foam board as an option.

Pros and Cons Using Foam Board to Skirt an RV

Pros:

• The cost.  We spent just $106 on all the materials to skirt our 37-foot camper.
• The durability.  It stayed in place and we could have used it the following winter if we hadn’t needed to move our camper.  We actually ended up leaving it on through the summer and it stayed nice and cool underneath through the hot summer months.
• Protection from cold.  That’s the whole point, right?  Our vinyl skirting worked just fine for us in temperatures below freezing down to about 0 degrees F, but if I were planning to spend winter in a place where the temperature regularly dipped below zero, I would trust foam board skirting more than I would trust vinyl.

Cons:

• Not environmentally friendly.  A big downside for me that it can’t be easily re-used or transported, meaning you may end up throwing it away and replacing it if you plan to move to a different spot each winter.  I was hoping to recycle the foam when we removed it, but the only place I could find that accepted styrofoam for recycling wouldn’t accept our skirting because it was dirty at the end of the winter.
• It doesn’t allow you to move.  The main reason we chose vinyl skirting over foam board skirting to begin with was that I wanted a type of skirting I could take down and put back up without too much trouble in case we needed to move during the winter.  Our billboard tarp skirting ended up being a lot more of a hassle to up up and take down than I had hoped, especially when got wet and muddy, but at least it was possible to reuse and could be folded up for transport.  Foam board skirting is really intended to be left in place all winter long.

If you will be moving a lot during the winter and need a type of skirting that you can quickly take down and put up, I recommend checking out AirSkirts.  This type of skirting didn’t exist at the time we were living in our RV, but it’s inflatable skirting made from heavy duty, puncture-resistant vinyl that you inflate with an electric or battery-powered pump (kind of like inflating bounce house at a carnival).

The cool thing about AirSkirts compared to traditional vinyl skirting is that it doesn’t actually attach to your RV, so you don’t have to drill holes or put anything adhesive on your camper.  As it inflates, it takes shape around the various parts under your RV, and these hold it in place.

Returning to our foam board skirting….

Materials We Used for Skirting Our Fifth Wheel with Foam Board

Here is a list of materials we used:

• 1-inch thick foam board insulation.  The kind we used had silver reflective material on one side (which goes inside to reflect heat back under your RV).  You can use a thicker type of foam board of you want, but 1-inch worked just fine for us and it is the cheapest.  And the main reason we chose it was because it was white with no ugly writing on it, so the end result looked a lot nicer.  If you plan to leave it up for multiple years, I would choose a thicker foam for durability.  You can paint it a different color if you like, as long as you use only latex-based or water-based paint–oil based paint (including spray paint) will react with the foam, causing it to “melt” or dissolve.
• Foil HVAC tape.  This is the best type of tape to use for attaching the foam board to your camper because it will stay stuck during cold weather but will pull away cleanly without leaving behind any sticky residue when you need to remove it.
• White duct tape.  We used duct tape to join pieces of foam board at the seams.  We chose white duct tape so that it would look nicer (since the foam board we used was white).
• Tent stakes.  We used tent stakes to hold the skirting in place along the bottom.  This will only work if you have a dirt ground that you can pound stakes into, though.  I’ll provide ideas for holding the skirting in place on other types of ground later in this article.
• A permanent marker. For marking where to cut the foam board.
• A tape measure.  For measuring your camper in order to determine how much foam to buy, and for measuring the foam board for cutting.
• Something to cut the foam board with.  We first tried a utility knife (the kind that uses razor blades) and found a knife worked better, but there may be some even better tool for the job.  Let me know if you figure out what it is!

Video of the Installation Process

My husband and I recorded video demonstrating the process as we made the skirting, which you can watch below if you are the type of person who would rather watch a video than read a long article.  (If you would rather read and look at pictures, scroll on!)

Measuring & Cutting

The first step is to measure your camper and determine how much foam insulation you’ll need.  This will depend not only on the length of your camper, but also how high your camper sits off the ground. If you’re parked on a slope, you’ll probably have more space on one end of your camper and need more foam to cover the height.

Unfortunately I can’t remember exactly how many pieces of foam board we bought, but I believe it was around 6 or 7.  A smaller camper would require a lot less.  Most of our camper required just 2 feet of skirting height, and since the sheets of foam insulation were 4’x8′, we were able to cut them in half lengthwise and cover 16 feet of our camper with just one piece.  However there were a few spots where the height was greater than 2 feet, so we had to patch in different pieces.  Honestly measuring and calculating how to cut the foam board is probably the hardest part of the whole project.  I recommend drawing it out on a sheet of paper first.

In this photo, you can see me marking along the foam board so that we know where to cut.

Next we scored the foam board with a knife, then folded the foam board along the cut and ran the knife down the crease on the back side to cut it all the way through.

After we had cut several pieces, we put them where they were going to be used so we could see what we still needed to cut.

Optional: Put foam board on the bottom of your slides.

You don’t have to do this, but I have found that attaching foam board to the bottom of each slide really helps to reduce heat loss through the floors of my slide-outs and makes the camper feel a lot less drafty.  If nothing else, I would definitely do this to any slides that won’t have skirting around them, like a bedroom slide that is so high up that the skirting won’t reach it.

Here is a photo of what I mean from a previous year, only I do NOT recommend using duct tape to attach the foam board like we made the mistake of doing in this photo–that tape was very difficult to remove and left behind residue.  As I’ve already mentioned, I recommend using foil HVAC tape instead, which is what we used in subsequent years.

Placing the Pieces

Here I am attaching the first piece of foam board insulation.  Note that if you’re using a type of foam board that has a silver reflective material on one side, the silver side goes INSIDE, facing underneath your camper.  This is so that the heat will be reflected back under your camper.  If you put the silver side facing outward, it will do nothing except reflect sunlight away from your camper, which is the opposite of what you want!

This side of our camper was sitting in gravel, so following a tip from one of our neighbors, I dug out a trench (using the claw side of a hammer) for the skirting to sit in….

…then I packed the gravel up against the skirting on both sides (I packed it on the back first) to help hold it in place.

Unless you’re in a location that gets very high winds, you may not need to do anything more than this to hold the skirting in place along the bottom, but if you are in a very windy area or if you don’t have gravel, read on because I’ll be sharing some other ideas for how to hold the skirting in place.

After the skirting was placed where I wanted it, taped it to the camper using the foil HVAC tape.  I used only enough to hold the skirting in place because we planned to come back and seal it all later.

Note that this piece of skirting came up higher than the bottom of our camper.  We felt that it was unnecessary to cut the foam board to the exact height; it was much easier to just cut each piece of foam board in half lengthwise since 2 feet of height was adequate for most of the camper.

In this spot, a 2-foot piece of foam board ended up being the perfect height, coming just under the edge of our camper.

On one side of our camper, the ground was dirt instead of gravel, so to hold the foam board in place on this side we pounded tent stakes into the ground on each side of the foam.  This worked very well and also made it easy to remove a single panel if we needed to access the area underneath the RV for some reason.

Here’s a photo of one of the tent stakes on the inside:

Instead of HVAC tape, we used duct tape to join the pieces of foam board to each other and to cover the seams between pieces of foam board because it was sturdier and leaving behind residue was not a concern.  We chose white duct tape to match the white foam board so that it would look nicer.

Tricky Spots

Here’s how we handled a few of the trickier parts of our RV, where a straight-edged piece of foam board would not work.

For the front of our RV beneath the cargo access door, we had to cut the foam at a curve.  This wasn’t really too difficult; we just used a marker to mark it first before cutting.

Here we had to cut out a hole for our sewage hose.  We use a few pieces of vinyl guttering elevated on one end with cinder blocks to make a downhill track for our sewage hose so the liquid will drain quickly and completely when we open the tanks to empty them.  This way we can leave our sewage hose exposed even in freezing weather, as long as the temperature outside is not cold enough that the liquid would freeze while running through the hose before it reached the sewage hole.

Here I cut the foam to go around this fender (I later came back and covered the gaps with HVAC tape to create a seal).  The height at the top of the wheel well was more than 2 feet, so I cut a small piece of foam which I attached with duct tape to patch along the top.

Here’s the back

My husband had a different approach to skirting the fender area on the other side of the RV.  He simply removed the fender to make it easier to cover.  If you do this, you might want to cover the holes with some HVAC tape to prevent them from rusting.  I don’t think rust was a problem for us, but you never know.

We just stashed the fender piece underneath the RV with the screws taped to it so they wouldn’t get lost.

This part of the RV was kind of tricky because it involved different heights and we also wanted to make it easy to access our water connection (in the ground under the corner of the slide) if needed.

Here’s what that area looked like after we got it done.

The steps can also be challenging to figure out.  Here’s what we did.  After installing the foam, I later covered the opening behind the steps with a piece of vinyl (cut from a shower curtain).

Sealing the skirting with tape

After all of the skirting was in place, we taped along the top of all of it using HVAC tape.  We did this both to create a seal that would prevent heat from escaping and to create a neat, finished look.

We were really happy with how our skirting looked finished, and even happier knowing that we would stay warm and cozy inside our RV without having to worry about our pipes freezing.

To be honest, I liked this skirting better than our vinyl skirting because once it was finished, it stayed in place, whereas the vinyl skirting sometimes fell down in places on windy days and had to be hung back up.

We decided not to skirt around the front of the RV this time, partly due to the cost of so much foam, and partly due to the hassle of making skirting that would go around the tongue and tripod.  That part of the RV is where our closet is located, and to help prevent heat loss there I had previously lined our closet with faux wood planks made from foam that provided extra insulation.

In the past we tried making vinyl skirting to go around that part of the RV, but it was really difficult to get it to stay in place and the wind would frequently blow under it.  I think in the future if I wanted to skirt that part of a fifth wheel I would invest in a commercially made wind skirt like this one that was specifically designed for that purpose and also provided easy access to the storage underneath (since my previous attempt to add a zipper to the skirting I made didn’t go so well).

Ways to Secure Foam Board Skirting Along the Bottom

As promised, here are some suggestions of ways to secure your foam board skirting so that it stays in place even in high winds.

• Gravel – If you’re parked on gravel, dig a trench for your skirting to sit in, then pack the gravel up against the skirting on both sides.  This is what we did.
• Snow – If you are spending winter in a place where snow stays on the ground all winter long, you can pack snow up against the foam board to hold it in place, and this provides extra insulation as well.
• Tent stakes – If you’re parked on dirt or grass, you can use tent stakes on each side of the skirting to hold it in place.
• Spray foam – You can run a line of expanding spray foam sealant along the bottom of your skirting on both sides to fill gaps and attach it to the ground.  If your camper is sitting on pavement or concrete, you can put down plastic first (a commenter on my YouTube channel suggested Saran Wrap) so you don’t end up with the difficult task of scraping up all of the foam later.
• Bricks or rocks – If you don’t mind hauling bricks (or buying them only to sell or give away later), you can put bricks on each side of the skirting to hold it in place.  Large rocks would work too–even better if you have a bunch of rocks laying around that you don’t have to buy.
• Lumber – Many RVers build a wood frame around the base of their RV to create a structure to attach the foam board to.  If you are handy with tools this might be a good option, especially if you have access to free wood.
• Sand bags – One RVer who was parked on a concrete pad told me he held his vinyl skirting in place using sand bags which he purchased online and filled with play sand.  He ended up just dumping the sand at the end of winter, but I’m sure if you were to advertise free sand you could find someone who would be happy to take it off your hands when you were finished with it.
• Gallon jugs of water – One year we used plastic gallon jugs filled with water to weight our vinyl skirting, and these could be used to help hold foam skirting in place as well.  An added bonus to this is that you’ll have water you can melt and use in emergencies, and a second added bonus is that you can tell by whether the water under your camper is liquid or not how effective your skirting is at keeping the temperature above freezing.  Please recycle the jugs when you’re done with them instead of throwing them away if you choose this method.

Do you have other ideas for securing foam board skirting, or any other tips for skirting an RV to share?  Leave a comment below!

Click here to read about other ways we prepared our RV for winter to protect it from freezing and prevent heat loss.