Insulation For Campervan Roof, Walls & Floor Guide

Want to relax in your van without sweating or shivering all night long? Then sorting insulation for campervan roofing, walls and floors is an absolute must!

New Zealand is blessed with some of the world’s most spectacular wilderness, but with it comes some pretty extreme weather. So if you’re taking on a DIY campervan conversion in the land of the long white cloud, van insulation is a key step to creating a pleasant living space.

But what about those sweltering summer camping trips? You might’ve heard that insulation is a bad idea if you plan to camp in hot climates, as it can hold heat inside your cabin. While this might be true for basic builds, insulation will actually support temperature control in any van with an electrical system and vent fan.

So now you want to install insulation for campervan roofs, floors and walls but don’t know which materials to go for? Below, we discuss the ins and outs of van insulation so that you can camp comfortably in any season.

As a van owner, you can earn over $10,000 each year by hiring your campervan out on Camplify. As a holidaymaker, Camplify helps you to find the perfect rental so that you can experience the joys of van life without having to own one yourself.

Interested? Learn more about Camplify at the end of this article.

Safety Disclaimer: We are not professional builders. Performing structural work on your van is a safety hazard so you need to do your research, double (and triple) checking that the below information is correct and safe to apply to your build. Before you begin, always discuss your plans with a certified builder, who should also assess and approve the finished work.

Why is insulation for campervans important?

Campervan example: Kowhai the Vintage Kombi

Radiation

Radiation occurs when heat moves through the air - like the warmth of a crackling campfire! Windows will be the prime source of radiation in your van, especially on scorching summer days when sunlight streams through to create a sauna on wheels...

Luckily, you can deflect radiant heat away from your van with some reflective window coverings. A winner all year round, they can be flipped to retain heat inside your van during the colder season.

Conduction

Conduction, on the other hand, occurs when heat moves through solid surfaces, like your van’s roof and walls. On a warm summer’s day, conduction transfers heat through the metal body of your van and into the cabin. It can also transfer heat out of your van on a cold winter’s eve. Not great.

Insulation for campervan roofing, walls and floors will hinder heat transfer via conduction, meaning you can chill out in comfort no matter the temperature.

Convection

The heat inside your van is continuously rising, thanks to a natural process known as convection. Insulating your campervan’s roof is key to retaining warmth inside the cabin. If you can part with the extra headroom, we suggest installing thick campervan roof insulation.

What if you want to get rid of this rising heat? A ceiling vent fan works wonders for keeping cool in warmer weather, extracting heat while it pulls in cold air from below.

Heat resistance

Insulation slows down heat transfer across your van, making it a whole lot easier to control the temperature inside. So if you insulate your campervan properly, it will be cosier in the winter and cooler in the summer. What’s not to like?

Every insulation product has an R-value, which measures its resistance to heat conduction. The greater this metric, the more effective the material is at slowing heat transfer. As space is oh so valuable when you’re living the van life, make sure to use insulation with a high R-value!

The best van insulation materials

Sheep wool insulation

Recommended use: Walls, Roof, Door Panels

Sheep wool is quite possibly the gold standard for campervan roof and wall insulation.

Eco-friendly, non-toxic and mould-resistant, it’s also renowned for its breathability and moisture management. Sheep wool naturally absorbs and evaporates moisture in the air, protecting your metal wall from condensation as it insulates. That means you don’t have to fret over correct installation, which is a major plus for any DIYer!

And to top it off, sheep wool even has sound-deadening properties for peaceful camping trips.

But it’s not all sunshine and rainbows. Sheep wool is more expensive than other insulation materials, costing about $200 - $250 per roll (with one roll covering anywhere from 10 - 20 sqm).

As such, wool is not the best option for budget van conversions. And as it has a relatively low R-value, you’ll need to pack it on thick compared to foam boards or spray foams. That means more costs and possibly less interior space.

Our opinion? If you can afford sheep wool insulation for your campervan, it’s an awesome option! If not, consider other options.

Foam board insulation

Recommended use: Walls, Roof, Floor, Door Panels

Rigid foam boards are a great option for insulating your campervan, especially if you don’t have much money to spare on your van conversion. It’s the most cost-effective insulation material, boasting a high R-value without taking up too much living space or blowing your budget.

But be warned: correct installation is critical with foam boards. If you’re not careful with its placement, condensation can get trapped behind this insulation, which will eventually lead to rusting.

Polyisocyanurate foam boards

Polyiso is a top choice for campervan wall and roof insulation. While more expensive than other types of foam board, it has the greatest R-value. It also tends to be foil-faced on one side, serving as a radiant heat barrier if installed with an air gap.

Extruded polystyrene foam boards

Extruded polystyrene (XPS) is excellent for insulating your campervan’s floor. Thanks to its high compression strength, you can stand on top of a sheet as thin as 1.27cm without damaging it. This form of foam board also has a high R-value but is slightly cheaper than polyiso.

Expanded polystyrene foam boards

Expanded polystyrene(EPS) is similar to Styrofoam, yet many subtypes have a foil-faced side for radiant heat deflection. While it has a lower R-value than other foam boards, its affordability makes it a strong choice for budget builds.

Spray foam insulation

https://www.youtube.com/embed/l_ZYi6AcPmU

Video URL: Camplify Van Conversions | Insulation Part 1

Recommended use: Gaps, Nooks And Crannies

Spray foam is a lifesaver for insulating those tiny, hard-to-reach spaces. Covering irregular surfaces in seconds, you can ensure that all gaps in your insulation are sealed properly.

It is possible to use spray foam insulation throughout your entire van. However, it’ll cost you heaps (you’ll have to purchase a kit) and make a serious mess if you’re a first-time sprayer. That’s why we recommend reserving its use for any voids between your foam boards.

Fibreglass insulation

https://www.youtube.com/embed/hj8Y6jlx0KU

Video URL: Camplify Van Conversions | Insulation Part 2

Recommended use: Door Panels

The dead space inside your campervan’s door panel can be filled with fibreglass for extra insulation. However, we do not advise using fibreglass insulation for any other parts of your van.

With the vibrations of a moving van, this particulate insulation can gradually degrade and release harmful molecules over time. Fibreglass is an irritant, so you don’t want to inhale or touch it in any way!

If you decide to install fibreglass, make sure to cover it with bin liners. That way, you can block nasty particles from entering your living space.

Reflective foil insulation

Recommended use: Windows and Windshields

Windows are by far the biggest culprit for letting heat in and out of your van. There’s almost no point in insulating your campervan or caravan if you ignore these big panes of glass! And with foil insulation, it doesn’t take much money or effort to make your van as comfortable as possible.

You can make your own window coverings with insulation foil, reflecting radiant heat away from your van’s interior. And when the cold weather rolls in, flip them over to keep any warmth inside.

Alternatively, attach tinted film to your windows. This will help to keep out the heat and give you an added layer of privacy during the day.

Lastly, always cover up your windshield when you park up in the sunshine. There’s no reason not to, with all sorts of budget-friendly windshield coverings to choose from!

Is a vapour barrier necessary for van insulation?

The short answer: Nope.

With vanlife comes lots of moisture, be it from heating, cooking or just plain breathing. Unfortunately, humidity reacts with the cold metal body of your van to form condensation. If this gets trapped in the walls, it can lead to issues like rust - which is a death sentence for older vans.

But will a vapour barrier actually stop this process?

Some van lifers insist on installing a vapour barrier on top of any insulation, as it will protect the metal body against moisture. We respectfully disagree.

If your van is well-ventilated (and it should be), then installing a vapour barrier is unnecessary. If anything, it might increase moisture build-up by creating a pocket that traps condensation if not 100% sealed.

So instead of wasting valuable time, energy and dollars on a vapour barrier, focus on installing proper ventilation. Paired with insulation, a vent fan will not only maintain a comfortable temperature inside your van but also draw out moisture from the air.

What’s more, foam board insulation and spray foam are impermeable to moisture. Essentially, they are vapour barriers in their own right. And for fool-proof protection no matter how successful your installation, use breathable materials (like sheep wool) that allow moisture to evaporate instead of accumulating.

Testing out van insulation before you commit

It’s easy to go wrong when planning your van conversion. Some people don’t use enough insulation in the roof and walls of their campervan, whereas others use too much. You need to find a comfortable middle ground that suits your campervan, your style of travel and your own body temperature!

That’s why we always recommend that you ‘try before you buy’.

Use Camplify to search through heaps of privately-owned Kiwi campervans for hire - many of which have been converted by their owner. Hire a van that takes your fancy and test to see whether its insulation meets your needs before undertaking the changes in your own campervan.

Once you have your insulation sorted, rent out your campervan through Camplify and begin making back the money you’ve invested.

Earn a return on your campervan insulation

You might be wondering about the average cost to convert a campervan?

No matter how big or small your budget, there’s a quick and easy way to start earning a return on your campervan - rent it out on Camplify when it’s not in use!

Instead of letting your campervan sit idly in the driveway, hire it out and make money from the comfort of your own home. Holidaymakers love campervan rentals that are well insulated to keep them cool in the summer and warm in the winter!

Why Camplify?

Each year, heaps of Kiwis earn up to $10,000 by hiring out their campervan through Camplify. It provides a quick and easy way to generate long-term passive income and earn a return on their investment.

And the best part is, Camplify takes care of many of the expenses involved in hiring out your vehicle, including:

• Comprehensive hire insurance.

• 24/7 AA nationwide breakdown cover for hirers.

• Dedicated customer support.

If you’re interested in joining Camplify as an owner, try our earnings calculator and see how much income you could generate each year by renting out your unused campervan!