In this post we'll cover the basics of insulating your van conversion with Havelock wool. This is one of the best all-natural options we have found for van insulation. We'll talk about our decision to go with US-based Havelock wool vs other options, and how we installed the wool in our Sprinter Van conversion.
If there’s one thing for certain in the van world, it’s that everyone has their own way of doing things. I guess that’s one thing that draws many of us to this ‘alternative’ lifestyle: we like to live life on our own terms. Choosing how to insulate your van is probably as controversial a subject as any when it comes to van conversions, and our method might go against the grain even more than usual. As is a common theme in our van builds, we chose to use the most natural yet functional insulation we could find for our second Sprinter Van conversion. Read on for our reasoning about why we chose to use wool insulation (again), as well as our installation methods and thoughts on what we might do differently next time if we run into any issues. We’ll keep this page updated with any new developments down the road, so check back here for future observations.
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UPDATE Jan 2019: We've been getting a lot of questions about how we're liking our wool insulation now that we've lived with it for a few months of winter. We are happy to report that the insulation has done as well in winter as summer and we still can't find any downsides to wool! Judging by how many questions we get about Havelock's insulation, it seems like this whole wool thing is finally taking off in the van conversion world, and we couldn't be happier about it. If you've got detailed questions about wool insulation that are not answered here, we suggest getting in touch with the guys at Havelock. They are way more knowledgeable than we are and very helpful. Cheers and happy building!
We chose to use all natural wool insulation for our second Sprinter Van build, made by Havelock Wool. The company is based out of the Reno, NV area and is run by some genuinely cool human beings. A few days after placing our order with Havelock, we received our shipment of a few highly compressed bags of Havelock’s insulation, both in traditional batts and ‘loose fill’. The batts (similar to the “traditional” pink fiberglass rolls, only not super toxic) worked great for all the bigger areas of wall and ceiling and the loose fill was perfect for stuffing into all the nooks and crannies. The guys at Havelock recommended that we open the vacuum sealed bags up and let the wool expand for a bit before actually installing the insulation, and we were impressed how big the insulation got as soon as we cut the outer bag off.
There are a lot of reasons we chose to use wool insulation again for our second Sprinter van conversion. First of all, it's probably the most natural, least 'processed' insulator that is practical for a van conversion. In addition to being totally natural, it is also highly efficient--not only at thermal insulation, but at sound deadening, air filtration, and managing moisture (if you live in a van you might have heard of condensation issues). Honestly, we don't know of a single drawback of using wool insulation, but we'll let you know if we find any.
The wool insulation we got from Havelock was ridiculously easy to install. Because it is 100% natural and nontoxic, we didn’t have to wear any protective equipment while working with it. Actually, I take it back, I did wear ski goggles while installing the wool in the ceiling so I didn’t get any itchies in my eyeballs, but we love wearing normal clothes and not having to worry about getting cancer every step of the way while building our van. We ended up insulating our van in stages, mostly because we did a lot of things (like installing our wall and ceiling panels) totally out of order. If we were not trying to live in our van while converting it, and were doing things in a ‘standard’ order of operations, we would have done all the insulation at once, then moved on to covering the walls/ceiling.
To fix the insulation to the ceilings, I wove some old string (actually upcycled paraglider line, because that’s what we had on hand) through the factory holes in the ribs of the van’s sheet metal. I basically formed a spider web of string to hold the batts up in place until we could install our ceiling panels and really hold the insulation in. For the smaller areas of the wall, I just cut and/or tore the batts to the correct size and shape and placed the pieces in the ‘cubbies’ of metal. They held themselves in well enough just with friction until we got the walls in place. The larger ‘window’ areas of the walls we held up in place and used a few pieces of gaffer’s tape momentarily as we placed the wall panels up.
As far as all the small areas of the van--and there are many--I stuffed the loose fill wool into every nook and cranny I could. I used a variety of tools for this job (mostly my fingers, screwdrivers, pencils, and the butt end of a ballpoint pen (because that’s what was on the floor of the van at the time), but as the build progressed, I accidentally happened to find that these odd little doingers that we bought for a totally different purpose were the best way to cram the wool into the hardest-to-reach nooks and tightest spots.
For our second van conversion, we chose to use wool insulation again. The first time around, we went with the only wool batts we could find on the market at the time, which came from Black Mountain Wool via Eco Building Products. The insulation was easy enough to install, performed really well in the van, and in general sold us on the whole concept of wool insulation. Our only reservations about that product were as follows: the company is based in Europe and imports its batts via Florida as far as we could tell. The insulation wasn’t compressed at all when they sent it, so it was quite bulky and inefficient as far as packaging. This seems like a pretty unnecessarily large carbon footprint. We also didn’t love the plastic backing that the batts were mounted on. The plastic mesh seemed unnecessary for our purposes and added weight and avoidable plastic to something that was totally natural to begin with and not so much in the end. We also had trouble finding any information about people that had used the insulation in a van and they best way to install it. Although they did their best to answer my questions, the guys at Eco Building Products were obviously not experienced at this application and couldn't really help me wrap my brain around the process.
This time around, we were much happier with the batts and loose fill from Havelock Wool. Besides being more impressed with the product itself, these guys obviously care a lot about their process and environmental impact from start to finish and are incredibly knowledgeable about all aspects of their wool. Being able to call Josh up and chat about installation, amounts, and curiosities was really reassuring and took much of the guesswork out of a nebulous part of the van building process. They have insulated their own Sprinter Van and have helped many customers with hands-on insulation so they totally get it. They are also outdoor enthusiasts themselves, so we immediately felt like they understood the way we use our van and the practical issues we face when making buildout decisions. Their phone numbers are published on their website and they encourage you to give them a call to discuss any questions before you buy!
Now, onto one very controversial part of our process. We decided to totally eliminate Reflectix from our walls and ceiling on this van conversion. We are still using the silver bubble wrap for window shades, but we are using wool as our sole insulator in the interior surfaces. We realize that many vanlifers will disagree with us here. However, after a few discussions with Josh at Havelock, we are convinced that the Reflectix is a waste of time, money, and space when it comes to the walls/ceiling of a van. Honestly, we’re not thermal engineers or insulation experts. However, we trust the guys at Havelock and have been super happy so far with our walls that are only insulated with wool. We haven’t been through a winter yet, but we’re sold on the wool-only method and we’ll let you know if anything changes.
If you have specific questions about how wool insulation functions or how it might be applied to your van conversion (or other project) we would encourage you to check out these resources and give Josh at Havelock a call with questions. Again, we are not experts and can do our best to share our personal experiences, but they have far more knowledge and real-life experience than we do and can probably help way more than we’ll ever be able to.
Havelock's website and some basic wool insulation knowledge:
Havelock's Vanlife-specific Information:
Read on for some FAQ’s that Havelock provided us to clarify some of the common questions people have about using wool in their conversions:
The insulation space is crowded, confusing and has become over run with low integrity, under-performing products. Wool insulation reverts to a time of natural, high-performance fibers that have evolved across time in nature’s R&D department. The head start is 1000s of years ahead of synthetic fibers designed to maximize profit, not performance.
We are fortunate to speak with van enthusiasts throughout the US and Canada every day, and slowly worldwide. It is wildly exciting to connect with cool people making interesting and exciting plans for whatever their definition of #vanlife might be. Wool as an insulator and sound dampener in your van is an easy decision once the rationale is understood; what follows is an effort to share the conversations and experiences for those of you embarking on a mission that can feel overwhelming at the start. We will continuously add to the list and encourage you to help us ensure nothing is missed.
With brevity as a guide, please consider we want to share and move on. If you seek clarity pick up the phone, we’re on the other end.
Do you (Havelock) have any experience with van conversions?
Yes, we have a high-roof Sprinter 144 crew van. We fit it our ourselves and are just now on a second round to enhance our experience. Note ours is more winter than summer given the passion to ski. Either way we appreciate preferences vary and there is no play book for how a conversion should unfold.
Why should we use wool in a van?
This answer is both simple and complex. The former is easy - the alternatives are toxic garbage. Conversely, there is nothing like a wool fiber. Nature’s R&D department looks back some 10,000 years. A wool fiber has evolved to protect sheep from the elements – hot and cold; damp and dry. The same goes for your van. Wool inherently manages moisture against 65% relative humidity (see below for more), absorbs harmful chemicals such as formaldehyde, NOx and SO2, crushes road noise and can be reused or composted (to grow award winning heirloom tomatoes) should you choose to move into a new rig.
What does moisture management mean?
Simply put: to temporarily absorb excess moisture and then release it back into the space when conditions change. Moisture in a cavity is inevitable, even an air tight one, given the simple properties of condensation and vapor drive. Taking its presence as a given, moisture needs an escape path. While in the cavity it can either be managed or degrade what it comes in contact with. If it is the side of your van, then rust enters the equation. If it is a sub-par material, then reduced efficacy and mold are both an issue. If it is wool, then you have a wildly dynamic fiber working in your favor. It will take moisture in when the ambient air exceeds 65% rh. When those levels drop below the threshold, moisture is dissolved adding to temperature control and indoor air quality.
Do other insulations manage moisture too?
NO! Cotton absorbs water and is treated with chemicals to be hydrophobic. Fiberglass acts like a sponge and then turns into a moldy science project gone bad. Cellulose is paper, attracts moisture and this too will become a moldy disaster waiting to happen. Synthetics like Thinsulate do not absorb water, but then where does the water go? It collects in the bottom of the cavity. Foam will not absorb water either but instead forces the water into the cavity to collect and corrode.
What is thermal bridging?
If a highly conductive material like metal reaches from the exterior to the interior of a building it will carry temperature differential in either direction. To simplify, think of a metal beam exposed to the inside and outside of a building. Now imagine cold wintery temperatures. The beam will carry the cold exterior temperatures within an inch (or finished wall thickness) of your living space and create noticeable cold spots. This is thermal bridging in its most simplistic form. Now fast forward to your van. The whole thing is a thermal bridge. Ideally you will find ways to create a gap or thermal break between the metal structure and your finished wall
What is condensation and why should I care?
Condensation is the conversion of a vapor or a gas to a liquid. It most often refers to the cycle of water. Think of it this way: you just bought a loaf of a bread at a bakery and are sitting at a table having a coffee in the sun. The bread and the (plastic) bag it is in started dry; as it heats in the sun, suddenly there is noticeable moisture inside of the sealed bag. Say hello to condensation. This is one example of many for this occurrence. Now think of the environments you and your van are likely to frequent and you’ll appreciate the inevitability of condensation.
Also, we suggest you let condensation concern you more than road noise. In the space between your van interior and the walls, condensation will flourish. If you insert the wrong materials so too will mold. Exposure to whatever grows therein is unhealthy at best and potentially dangerous.
What should I do with a vapor barrier?
Put it in the garbage. Condensation is inevitable and entirely unavoidable. Plan for escape routes not a feeble, misguided attempt at barriers.
How much insulation do I need?
Casting aside complexities, the easy answer is to say as much as you can fit in the space. The structure is a metal box; it changes temperature rapidly. Mitigating contact between the living space and the exterior elements is paramount to an enjoyable environment. Insulation will help dramatically and should be placed across the entire thermal bridge for the best results.
Should I stuff every little hole (nook and cranny)?
Yes, although time consuming this is a terrific way to increase thermal efficiency and relieve your OCD tendencies.
How do I measure for insulation?
Keep it simple. Measure the area you plan to insulate (height and length) and take note of the average depth. Once you have the square footage apply the associated depths and you will have an idea for insulation needed. Typically, we sell two or 3 bags of batts any overage should be used for stuffing all the various holes, door panels, headliners, nooks and crannies in a van conversion.
What should I do in the walls and floors?
This can vary greatly. Our experience would suggest building the floor up slightly from factory specs to allow for extra insulation to reduce road noise and minimize a cold/hot floor depending on the season. Walls will vary greatly based on the finish. Batts are generally suggested for T&G for ease of install and almost required for wall panels.
Is reflectix a good product?
No. Well maybe if you put it outside your van or in the windows. It is designed to reflect the sun. It has no place inside for all sorts of reasons – not least it needs an air gap to work properly, which is highly unlikely to be consistent in a van.
I hear lots of people use thinsulate, do you have an opinion?
Yes. Thinsulate was originally purposed in vans automobiles for sound attenuation. Wool is a better insulator and also better at minimizing sound. Thinsulate is certainly the lesser of other insulative evil mediums but similarly underperforming by comparison to our favorite natural fiber.
Any thoughts on foam board or spray foam?
Yes. Why would you ever put a toxic, petro-chemical based material in a confined space? Foam is a nasty material that should be discontinued. It does not address moisture challenges, is unsafe to breath, makes noise when driving and is likely to spend a few thousand years in the ocean once your van is repurposed. Please use common sense and don’t use foam.
What about sound deadening?
Wool has excellent sound deadening characteristics. Noise reduction coefficients are outperformers when tested. Anecdotally we constantly hear folks telling us how quiet their vans become once wool is introduced – note the ability to stuff wool in the headliner and voids in doors as a true difference maker.
What about air filtration?
Talk about a standout for wool. Other forms of insulation will emit something not good for you. Wool, conversely, will irreversibly bond with formaldehyde, NOx and SO2. There is NO OTHER INSULATION material available that will provide this service to your space.
Do I need A fan?
Yes, if you are sleeping or cooking than you will want one of these. Again, you live in a metal box and it needs some ventilation.
I live where it is hot, will wool insulation still help?
The same principle applies for all insulations in hot or cold climates. It serves as a barrier for thermal transfer.
Insulation works both ways, it keeps you warm in the winter and keep you cool in the summer. As an additional benefit of the wool fiber- the release and capture of moisture will help modulate the temperature making you feel warmer in colder environments and cooler in warmer environments.
How do I install Sheep’s Wool insulation?
This depends on your build. Ease of install would call for batts. Loose fill is just that and therefore not hard. It just may be a bit more time consuming. Our experience suggests a combination works well. Batts in walls, floor and ceiling and loose fill in nooks and crannies. Also, don’t be afraid to be creative. String can hold batts in place, you can stuff behind T&G boards or finished wall coverings as they go up. Said another way, we support creative alternatives over adhesives and other forms of ‘traditional’ methods.
Do I need to be concerned about insects?
No. We apply a minor amount of boric acid, which is all-natural and non-toxic, as an insect repellent. In addition, it is often the lanolin that attracts pests. Our wool comes from NZ where the most advanced scouring (cleaning) techniques in the world are employed to ensure a consistent, clean fiber is provided for our process.
Does wool insulation smell?
No. As noted above the kiwis are the best in the world at cleaning wool. The smell is left behind after scouring.
How thick should my insulation be, how much should I buy?
Your insulation should be as thick as your build will allow. We typically see 2” batts used across the van. Some spaces more some less. There is a surprising amount of room in the headliner. Measure the square footage and then note the desired depth; you will then know what to buy and how much.
Should I use batts and/or loose fill?
Up to you. A combination is fairly standard. Batts are malleable and easy to stuff in out-of-way places. They can be torn or shredded into piles of fluff for auxiliary stuffing. They can also be peeled apart easily with consistent results allowing you to stack thicker layers or use thinner pieces. No chemical binders make for a pleasurable experience. Loose fill goes anywhere but is best for all the totally random spots on larger van models like a 170 WB
Where can I buy it?
Call us and we’ll get you going in the right direction. Ever heard of Lake Tahoe? Some say it’s a world class destination – we think so. Come see for yourself.If you are driving thru the Reno/ Tahoe area please stop in and see what we are doing. Our doors are open 5 days a week and we welcome visitors – so long as you’re up for a beer!
Shipping is a nuisance. Bags are big and don’t weigh much; this is an annoyance for shipping companies which means they charge more. We are constantly working on new ways of packaging to minimize the logistical pain and will roll out options as they become viable. Please note residential addresses exacerbate the problem; seek out a business one if you can. We will work with you to evaluate multiple options but be prepared for the shipping to be less than desirable.
We compress the bags before shipment to help make the package denser/smaller and cost less to you. When you receive the bag please cut open the outer compression sleeve immediately and allow the wool to expand into the larger inner bag. The wool might need to acclimate for a day to regain its loft.
Full Disclosure: We made a marketing trade with Havelock in exchange for our wool. This means that they provided us with insulation in exchange for content. All opinions expressed here are still our own, and honestly, even if Havelock had denied our request, we still would have bought their insulation and sung their praises because we are 100% stoked on their product. We only partner with companies we believe in, and we wholeheartedly believe in Havelock wool. Please let us know if you end up using their insulation and what you think--we'd love to hear your experience!