Why We Chose Wool Van Insulation for Our Sprinter Van Build

So, you’re at that stage where you’re researching wool insulation for your van? Congrats! You’re well on your way to building out your dream campervan.

Wool van insulation has become increasingly popular over the years, and for good reason. It’s natural, sustainable, easy to install and is hygroscopic, meaning it absorbs water from the air. 

Those are all the reasons we used Havelock wool van insulation on our Sprinter van build.

Some van lifers have a hard time deciding whether wool insulation for a van is best, or whether they should go with something like Thinsulate. I know many people spend hours researching insulation.

In this article, we hope to give you all the info you need about wool insulation for a van, plus its positives and negatives.

How Much Wool Insulation Did We Use?

One of the first challenges van builders face is just how much wool van insulation to order. We have a 144″ wheelbase Sprinter van, and Havelock wool recommends 300-square feet for a van of that size.

At the time, Havelock sold wool in small and large bags, so we ordered two large bags for a total of 400-square feet. Better safe than sorry, right?

Now, Havelock wool is sold in 100-square foot boxes, so we would have ordered four of those.

Turns out we used 1.5 bags of the van wool insulation with a little bit leftover. I’m really glad we decided to go with extra!

Installing Havelock Wool Insulation in our Sprinter Van

Next came the process of adding all that wool to our Sprinter van build. Havelock wool comes in long batts. You can do single layers, double layers, or pull the batts apart to shove wool in small spaces and crevices.

We started by putting long batts in our campervan ceiling. We used packing tape to secure the batts. You can also use string or anything else you can think of to make sure those batts don’t fall down before you add your ceiling panels.

Then, we tore off long batts and cut them to size to fit in the wall panels. Finally, we tore off small tufts of wool and stuffed them into every crevice imaginable. I often used a long, stick to shove the wool as far into holes as possible. Fully insulating the van means less condensation, which leads to mold and rust.

It was a tedious process, but we finally filled up as much of the van as we could, even the crevices in all the doors.

We also chose to layer long batts of wool into our campervan’s headliner area. A big job!

Overall, the wool van insulation installation process went pretty well. We wore dust masks most of the time because wool does produce tiny fibers and dust that get everywhere.

I’d say it took us several days to insulate the entire van. Most of the time I was working on it by myself while Tom did other projects. Two people could get it done in a couple of days.

I’m So Glad we Chose Wool Van Insulation

Since adding the Havelock wool van insulation, I’ve really noticed a change in the Sprinter van. When we first bought the new van, it was an absolute rattle trap. So many sounds when we went over bumps, even driving down an even paved road!

The wool insulation is great for sound deadening, and makes the van very quiet when we drive it now.

We’ve also noticed the amazing insulating properties. When the sun hits the side of my van, the Stone Gray metal gets extremely hot. There’s pretty much a 30-degree difference when we compare the metal parts with the parts with wool insulation and wood paneling.

Also, the van really holds its heat at night as the temperature drops. There’s a huge difference between sitting inside the van – even with no heat – and being outside! I’ve been quite impressed by the wool’s insulating properties.

Positives of using wool van insulation

If you’re thinking of going the same route as us and using wool, here are the main positives. These are the factors that convinced us to go with Havelock wool.

It’s natural and sustainable

The main reason we went with wool insulation in our Sprinter van build is because it’s natural and sustainable. My van life partner Tom has sensitive lungs to chemicals and synthetic fibers. We’ll rest easier knowing wool isn’t off-gassing chemicals or leeching microfibers into the air. However, during the installation process, it does emit a ton of dust and small fibers, so a mask is encouraged.

We also love that wool for a van build is a sustainable and environmentally-friendly product. Wool is biodegradable, so goes right back into the earth and acts as a fertilizer. You can even use it as composting if you ever need to remove it from your rig for whatever reason, or if you have leftovers.

Compare that to synthetic fibers, spray foam or foam board.

As a couple who lives tiny in a campervan and on a sailboat, we care a great deal about our environmental impact and try to live sustainably.

Companies like 3M, which manufactures Thinsulate, go completely against our ethos. 3M is in $850 million settlement talks with the state of Minnesota for polluting ground water with cancer causing chemicals. We have a hard time supporting a company like that.

Wool is great for moisture management

Let’s face it: moisture is going to show up between your van’s outer metal shell and inner walls. The good thing about wool is that it absorbs that moisture [without becoming wet to the touch!] and then releases it when humidity drops to 65%. The moisture goes into the air and dissolves.

This is the same reason I love wearing wool undergarments for outdoor activities like hiking and backpacking. Wool clothes are great at absorbing moisture while still maintaining insulation, aka, keeping me warm.

If you don’t properly manage moisture in a van build, it can cause rust and mold. This not only affects your van, but can cause air quality issues inside.

Wool van insulation also has sound deadening properties

Wool insulation for a van has incredible sound deadening. Some people even choose to ONLY insulate with wool rather than adding sound-deadening materials. However, if you want additional sound deadening, feel free to also install something like Kilmat in your van. This is what we did, and we noticed a huge difference!

Wool van insulation also fits in those tiny nooks and crannies in your van that other insulation and sound deadening materials can’t reach, like your headliner area.

When measured using the Noise Reduction Coefficient (a rating for how well sound is absorbed), wool measures at 90%, which is a really high number!

Wool Insulation for a Campervan Provides Air Filtration

If you’re someone with sensitive lungs, you will definitely appreciate wool insulation’s air filtration properties. Wool actually bonds with nasty chemicals like formaldehyde, NOx, and SO2 and doesn’t re-release them into the environment. 

Researchers in Switzerland studied air filters made of wool, and found they absorbed 94-96% of pollutants over a six hour period.

In our van, we’d rather have an insulation product that absorbs chemicals rather than emits them, like some alternative insulation products on the market

Wool is really easy to install in a campervan

To install wool in a campervan, you can order 2” batts from a company like Havelock Wool. You’ll have to measure the square footage in your van without forgetting spaces like the headliner area.

It’s good to get enough wool to try to cover all the metal in your van. You’re basically living in a metal box and it’s important to create a barrier between that metal and your living space so you can properly regulate the temperature in your van.

The 2” batts are surprisingly versatile. They rip into puffs for those nooks and crannies and peel off into thin-layered “sheets” for larger areas. A lot of van lifers use string to secure insulation on larger van panels. 

Havelock recommends insulating everywhere, even your ceiling and floor. 

Wool has a good R-Value

R-Value is how a material’s resistance to conductive heat flow is measured. The higher the R-value, the better the insulation.

Wool insulation comes in with an R value of 3.6 per inch. Thinsulate, on the other hand, has an R value of 3.3

What’s cool about using wool insulation for a campervan is that the R value doesn’t degrade over time as moisture buildup doesn’t occur. 

We’d much rather go with wool, a natural substance with a great R-Value! What would you want to put close to your body?

Wool is mold-resistant

Wool is made out of keratin and doesn’t support the growth of mold. Plus, wool absorbs up to 33% of its own weight in water while still staying dry to the touch. Wool traps that moisture inside its fibers where mold spores can’t get to it. It insulates so well that it creates an inhospitable environment for mold.

You’ll also need to use proper ventilation in your van build to help move air around and help moisture dissipate. That means one or two fans in your ceiling and slider windows with screens.

Wool van insulation is fire resistant

Another great plus of using wool insulation in your campervan is that it’s naturally fire-resistant. That comes from the wool’s high nitrogen and water content. It will usually just smolder and burn away before it catches fire. 

Negatives of wool insulation for a van

With any type of insulation for a campervan, there are negatives that come along with each type. Here are a few things to know about wool van insulation.

It might smell like a barn

Wool comes from sheep, so it shouldn’t be surprising that it could smell like you’re on a farm, at least at first. Eventually, the barnyard smell will dissipate from your wool van insulation.

We did notice then when installing wool in our Sprinter van build. I actually thought it smelled good, and it has dissipated over time.

One way to hurry up the process is to open the bag and let the wool reloft and breathe for a couple days before installing it in your van.

This doesn’t bother most van lifers, but if you have a particular aversion to the smell of wool, you may not want to use wool insulation for your van.

Wool is treated with chemicals

Wool van insulation is treated with boric acid to repel insects. Companies like Havelock use just a small amount of boric acid to repel insects, which is all-natural and non-toxic. Boric acid is mined out in nature and is shown to have negligent toxicity levels when breathed or eaten.

It isn’t vegan

Kate and Ben of Two Wandering Soles pointed out that wool isn’t vegan, so it might not be the right insulation for you if you’re trying to avoid using all animal products.

It’s not quite as easy to install on large areas as other products

If you’re insulating a panel van, you’ll have large areas of metal where you’ll need insulation. For wool insulation for a van, you’ll need to use string or tape to make sure the wool stays in place. Some people prefer using an insulation like Thinsulate as you can just stick it to the larger panels.

We used packing tape to secure the wool to our campervan’s ceiling, and it was no big deal.

Be prepared to carve out a little extra time if you’re installing wool insulation in a van.

It doesn’t have the highest R value of all van insulation options

If you’re looking for the very highest R value of all campervan insulations options, wool doesn’t win. Spray foam is the highest with an R value around 6.5-7, but the tradeoff is huge. With spray foam, you’re introducing chemicals into a tiny living space. Also, if spray foam is applied incorrectly, it can damage your van’s panels.

The choice is yours to make – if using spray foam, it’s best to get it professionally installed by someone who knows how to insulate a campervan’s unique space and layout.

Where does wool insulation for a van come from?

Wool van insulation from a company like Havelock Wool is sourced from sheep in New Zealand, where wool is a huge part of the gross domestic product. The country is able to mass-produce wool that’s properly cleaned and graded for professional building.

The United States and Canada don’t make enough wool to sustain the amount of wool needed for insulation companies. Plus, wool from the U.S. typically contains 1.5% vegetable matter, things like burr, seeds, leaves, grass or twigs. Wool cleaned in New Zealand has only 0.1% of this plant matter. 

Havelock wool insulation for a campervan is sourced from high-quality farms in New Zealand.

Top Questions Answered about Wool Insulation for a Van

Here are some of the top questions we’ve seen asked in van build forums about using wool for campervan insulation

Will I need a vapor barrier with wool van insulation?

You do not need to put in a vapor barrier if you’re using wool insulation in your van build. A vapor barrier is meant to prevent vapor from moving around. The point is for wool to absorb any moisture, and release it when humidity drops below 65%. You want that moisture to be able to move out and dissipate. 

A vapor barrier would actually trap moisture, which leads to rust and mold.

Do I need to insulate the ceiling and floors, too?

It’s recommended that you insulate every part of your van that you can. Use string or tape to secure wool insulation to your van’s ceiling and walls. Insulating the floor is more a personal decision. We’ve seen people in van life forums who think it isn’t worth the effort. We haven’t done our Sprinter van floors yet, but might with a different type of insulation in the future.

However, if you plan on winter camping in really cold temperatures, you may want to insulate the floor so you’re not freezing your feet every time you walk around. Insulating the floor with wool will also trap heat from your van’s heater – preferably a diesel heater – for those super chilly temps.

Insulating the floor also cuts back on road noise. 

Where can I buy van wool insulation?

We recommend buying wool insulation from Havelock wool. This is a popular company amongst van lifers – and Havelock even has its own campervan insulated with wool.

They’re great with customer service and answering any questions you might have. This is definitely the company we’re going with when we insulate our campervan.

Conclusion about wool insulation for a campervan

Wool insulation for a van is great if you’re looking for a natural, non-toxic, sustainable option for your van. Wool is mold-resistant, fire-resistant, and soaks up moisture without getting wet. Wool is nature’s insulation with an R&D timeline of many thousands of years.

Wool van insulation stuffs easily into nooks and crannies, and you can hang it on the ceiling and in wall cavities using tape or string. Wool also has amazing sound deadening properties to quite your ride.

We plan on using wool insulation on our next campervan conversion. We hope this article helped you decide if wool is also right for you.

Click here to check out wool van insulation on Havelock Wool.