Step 9: The walls: third layer is the vapor barrier

The final step is to add the vapor barrier to seal everything. The goal here is to have no air coming from the van to the fiberglass insulation.
  1. Start by cutting an approximately good size piece of plastic for each section. For sections, we used the large beams already on the walls to dictate where we were going to separate the sections.
  2. For each section, start by using tuck tape on the top part of the piece to secure it in place.
  3. Then make sure to cut out space for the wheel for the bottom piece. Make sure the size is ok all around.
  4. Then tape down the bottom, and finish with the sides.

We had some more delicate cutting outs to do around the ceiling studs, and around the back anchor for the door. With some patience and good scissors, everything can be sealed out properly!

YOU ARE NOW DONE! The insulation for the van is complete. If you want a super extra good job, you can also add some insulation in the panels of the doors. We did not get to this part yet. You can also insulate around the wheels, but this has to be done in conjuncture with whatever you want to build around the wheels.

Once this is done, the next step will be to cover the insulation with a 'pretty' finish so that it is nice and welcoming to live in the van. Some people use thin plywood, some use plywood covered with fabric or rug. We are thinking of using thin cedar tongue-in-groove slats for a very nice finish. This will come in the next instructables tutorial!

As I said in the intro, this is the first van conversion we are working on. We do not claim that this is the best way to insulate the interior of a van, however we believe that we have done a thorough research of online resources and what we present here is a nice summary of the best options we have seen out there, considering our budget, our skills, our schedule, and our future use for the van (winter adventures!). We welcome all comments or questions, since we are curious to see how others have done it.

Questions? Comments?

<p>Thanks so much for this - a lot of great advice to mull over as I contemplate the same treatment for an old Step Van. Up to now Reflectix and Celotex was strongest contender, but spray-foam (shaved after curing) is starting to capture my imagination, as it could possibly be it's own vapor barrier.<br><br>I wanted to suggest that adding a bit of thick, self adhesive roofing material to the larger panels would go a long way towards deadening road vibration and quiet the ride. </p><p><a href="http://www.homedepot.com/p/Grace-Ice-Water-Shield-HT-36-in-x-225-sq-ft-Roll-Roofing-Underlayment-5003093/202800770?MERCH=REC-_-PIPHorizontal1_rr-_-203057407-_-202800770-_-N" rel="nofollow">http://www.homedepot.com/p/Grace-Ice-Water-Shield-...</a> <br><br>It would probably be noticeably more resistant to outside noise when camping as well. (That's what I'm banking on, anyway) </p>
Very good job, but every material you use is highly cancerigenous...this is something to think about it..
<p>=Increasing the risk of you getting cancer</p>
<p>My Ford E350 cargo van developed several small holes below the factory rubber floor which developed into surface rust everywhere on the floor. I painted over hard rust with POR-15 and put a breathable outdoor carpet from home depot over the metal.</p><p>Almost every Sprinter I see on the road today has rust weeping down the sides.</p><p>Have you run into any issues with rust on your Sprinter?</p>
<p>Hi AdamG10,</p><p>We have not run into rust problems yet as the van is a 2013 (so it is not that old yet). Also, we live in Vancouver, Canada, so our winters are really not that bad and there is not much salt on the streets in the winter time.</p>
<p>Has anyone experimented with expanding foam?</p>
<p>Hi powderstash,</p><p>We have used a bit of expanding foam for the beams where we could not add other types of insulation. Look at step 8, we describe it there. What we learned is that it does expand quite a bit! (about twice if not more in volume). I have heard stories of people putting some expanding foam in the doors of their van or car and if it expanded too much, it actually deformed the door... so be careful if you go that route!</p>
<p>Hi Guys,<br><br>I am looking at implementing a similar insulation scheme for my camper for an upcoming sabbatical. Unfortunatley for me time is short, so I was wondering if you could give an idea of how long each stage takes. <br><br>Ideally I could calculate using your awesome time lapse, what was the time delay on each photo?<br><br>Any info would be appreciated.</p><p>Regards</p>
<p>Hi TomAtWEG! Great to hear you are starting a similar project! Super exciting! For the timelapse videos, we set it up to take a photo every 30 seconds. Overall, it took us about 12-14 hours to finish the insulation. We always had 2 people at least working, sometimes 3 or 4. Also, not part of the videos is the time to calculate how much material we needed, the time to go and buy it, and the time for setting up the tools and such. But once you get going, it goes pretty fast! </p><p>Good luck on the project and have fun!</p>
<p>Nice job. This really is a complete and proper job with the vapour barrier as that wool can hold moisture. I recommend using tongue and groove like you say - it's easier to fit than cutting bit sheets of ply. This is how I insulated and cladded my van: <a href="http://vandogtraveller.com/fitting-wooden-cladding-van-interior/" rel="nofollow">http://vandogtraveller.com/fitting-wooden-cladding-van-interior/</a></p>
<p>Hi MikeH14, Thanks for the comments! We decided to go with tongue and groove cedar : <a href="http://www.instructables.com/id/Cedar-paneling-for-van-interior/" rel="nofollow">http://www.instructables.com/id/Cedar-paneling-for...</a> and it worked great! We have been traveling with the van on and off for a year now and it is holding up pretty good! </p><p>Your van looks awesome!! Hope the travels are good!! </p>
<p>Was wondering if you still around do you have any shots of the complete van once you finished all the layout?</p><p>Thanks a million for the tutorial looking at vans at the moment for travelling around Europe on vacations for the years ahead. </p>
<p>Hi Killerspec,</p><p>Sorry for a slow response! We are still working on the van. We decided this was going to be a slow process, so we could still go travel with the van as we are building it. As of now, we are done with the walls, we made a platform for storage in the back and we build a table with benches and a bed. You can find all those tutorials here:</p><p><a href="http://www.instructables.com/id/Storage-platform-for-the-back-of-your-Sprinter-van/" rel="nofollow">http://www.instructables.com/id/Storage-platform-f...</a> </p><p><a href="http://www.instructables.com/id/Cedar-paneling-for-van-interior/" rel="nofollow">http://www.instructables.com/id/Cedar-paneling-for...</a></p><p><a href="http://www.instructables.com/id/Bed-Table-and-Benches-for-camper-van-All-in-one/" rel="nofollow">http://www.instructables.com/id/Bed-Table-and-Benc...</a></p><p>I have another one drafted for the cushions of for the bed, so stay tuned! Next step is to build the kitchen unit :)</p>
<p>Thanks for getting back to me good luck with the rest of the project and I look forward to seeing the fruits of your labour in the near future.</p>
<p>Did you make sure there are no access covers for the fuel pump or rear axle mounts that go throught the bottom of the van?</p><p>If access to the fuel pump is through a cover in the bottom, you'll have to have the flooring sawed to fix the fuel pump, clean the strainer, etc.</p>
Hi, <br>Fiberglass (and most any foam) insulation is bad news. Take it out now and avoid the rust problem that follows. Seen way too many VW buses over the years with the nasty results. Sealing it with plastic will make it load up with moisture even worse/sooner. Only way to make that work would be to cut the sides of the van and install vents to allow out the condensation like as done to houses.
<p>Veewee111...Hi...I was thinking the same thing about the condensation. Starting a van build now and wondered if you had any solutions to the moisture issue...</p><p>Thanks!</p>
Sent the below to a fellow who Pmailed us about this problem. Have added some more to it to post it here.<br><br>There are two catagories to insulating a camper or any other structure, short term or long term.<br><br> Short term like a few days to a few weeks then you could insulate the walls when camping in temperate weather, but need to allow moisture to get back out of the walls back to the interior to be let out of any venting window. We have side windows and a roof vent that can be slightly opened on sunny days, that really helps.<br><br>Long term for months and especially in artic conditions one would need to insulate with vapor barrier and cut vents in the outer walls to let moisture vent out all of the time. VW did this to the pre-1968 non-walk thru panel buses with a panel sealing off the cargo area from the front bench seat, by punching vents in the upper rear corners of the rear cargo area to prevent moisture build up.<br><br>Image looking forward to the panel behind the bench seat of non-walk thru panel bus.<br>http://images.thesamba.com/vw/gallery/pix/267582.jpg<br><br>Here is an interior shot of a special order walk thru panel with the upper cargo area vents in the body. These vents were usually only in the non-walk thru panels.<br>http://images.thesamba.com/vw/gallery/pix/1116625.jpg<br><br>Here is a post on a VW website we have weighed in on about the subject for short the term.<br><br>http://www.thesamba.com/vw/forum/viewtopic.php?t=153837&amp;postdays=0&amp;postorder=asc&amp;highlight=insulation&amp;start=0<br><br>Thinking of using thin 1/4&quot; (6 mm) styrofoam glued to the mylar coated bubble wrap. Neither of these insulation materials will sponge up moisture. Insulation needs to be thin enough to not be packed tightly in there against outer sheet metal when paneling is in place. Want a bit of air space so air flow can pass thru and get out the moisture from behind the 1/8&quot; (3 mm) plywood. Having the mylar coated bubble wrap with the bubble side against the outer sheet metal will allow air to dry out any moisture that gets in between the insulation and sheet metal. The wood unlike plastic will breath back out the moisture when heated up in the sunshine or a heated garage. Will use velcro in places to hang the insulation from drooping down and at same time allow air flow around edges of the insulation. That way insulating panels stay in place, but easy to remove for body repairs or inspection.<br><br>Was in the USAF and got to handle the insulating panels used in cargo aircraft like the C-130s. Blanket type material with velcro at edges. Very cold at 30,000 feet over the North Atlantic with temps down near -50 F. Would pull back a panel, and slip in a 1 liter bottle of Moutian Dew for fifteen minutes. Pull the bottle back out and shake up for slurpies. Yum!<br><br>Hope this info helps!<br>
<p>Wow Veewee111!! This is quite the response! Thank you so much for sharing all this information. I think this should help other folks figure out what they need for the usage of their van. I think a key point that you shared is the need to have air circulation between and around the insulation. In our build, since our cedar panels are almost floating in front of the metal wall, we were able to have about half an inch of air circulation. This should definitely help. </p>
<p>Ah that's sweet as! Nice job!! Did you find out about the temperature difference? And have you had any problems with the setup as of yet I.e rust, dust, ventilation, condensation or anything else? I am looking to carry out the same to my Mazda bongo to live in the winter months whilst at work! So very curious on how it's going? :D enjoy!!!</p>
<p>Hi smidGe777! Thanks for the comments and sweet that you are starting a similar project! We have had the van since November 2013 now, and finished installing the insulation and wood paneling walls (instructables to come...) in December 2013. We have used it to camp in the winter, spring and summer. Up to now, we have not had any problems with it :) We are pretty happy with how things are working for us and it seems like there is no condensation happening in the walls (although it is hard to see because most of it is now covered in cedar panels). We did not do a serious comparison for the temperature difference, however, we spent nights at -10 or -15 celsius and we were fine. We use a small propane heater (made specifically for indoors environments, and with the ceiling vent open) and it has kept us warm enough. For ventilation, the ceiling vent is crucial, and even in winter time it is important to leave it a bit open at night, to let the humidity get out. We have also definitely noticed that the windows and the side door were conducting the cold from outside, since they were not insulated. For the front and back windows, we made curtains. For the side door, we are in the process of adding a window, and eventually curtains as well. We used a light wool for the curtains. </p><p>Enjoy the project!</p>
Nice one! Glad your happy with your project! And thank you for your wishes and advice :D
<p>Wow, so very jealous. Great work. I particularly liked the hands-in-the-air moment in day one!</p><p>I did a complete conversion myself some time ago and wrote it up with a few photos here: http://loftsites.co.uk/campervans/vw-lt-camper-conversion.html</p>
<p>Hi Timaldiss! Thanks for the comment! Yes, it was almost like a dance with everyone's hands in the air! Nice work on your conversion. We will soon start on making a seating area and a table. How did you brace the different plywood panels? Did you just glue them together or nailed them as well? I think I saw some angled braces as well, did you put those everywhere? Thanks!</p>
I used quite thick heavy ply which in some cases I did screw together, yes, but in the most part it was right angle brackets.<br><br>I used Sikaflex to bond all the wood panels to the metal bracing in the van - this is key to stop rattles.<br><br>Have fun :)
hi, great job. I had an older VW van with insulation much like yours - except the builder (not me) had forgotten the vapor barrier. My point here would not be mould, but rust. When my van started to show brown dots in the outside seams of the sidepanels it was too late - it had rusted from the inside. <br>Could this be a problem with your floor and ceiling? Condensation could occur if vapor is allowed to pass to the metal panels. <br>best rgds <br>Martin <br>
<p>Hi! Thanks for the comment. This is a good point, we will have to see with time. I think that the metallic bubble wrap as well as the foam for the ceiling are less likely to hold and maintain humidity over time than fiberglass wool... is that possible? Assuming this is true, rust (or mold) would be less likely as well...</p>
What do you think about: http://kore.koskisen.com/ ?
Really neat project you have here. :) <br> <br>One thing about finishing the interior, keep in mind the weight of the wood. You might be surprised how fast it adds up and that will kill any mpg in a hurry. Indoor/Outdoor carpet is made to get wet and dirty, so it cleans up fairly easily plus it's cheap. Less than .50 sq ft in my area(Minnesota). Carpet will also help keep dust down when everything does dry out. I've done a few van conversions back when I was much younger and so far you've done great IMHO only other thing to be careful of is after running your wiring try not to run any fasteners into them (really sucks when the back speakers stop working out of the blue LOL). <br>Wishing you best of luck on your adventures to come :)
Thanks for the comment! (and the advice hehe!)
On my own van, I originally planned to use bubble insulation like Reflectix which includes foil to block radiant heat. I'm having second thoughts after googling Reflectix and learning that its real R value is just about 1, and that radiant heat transfer isn't relevant to most real-world situations. Maybe I'll try closed-cell foam, as used for camping mats. It doesn't absorb moisture, and should also add sound deadening.
Good stuff - love Sprinters!! <br> <br>I don't know if fibreglass provides more effective insulation than polyester, but poly is another option for people who are turned off fibreglass. Poly is so so much easier to install. <br> <br>BTW do you have a forum thread or anywhere with regular updates on your fitout?
Hi Mugget, <br> <br>Thanks for the comment! We don't have a forum thread anywhere for now. This was only the first step and we are thinking about adding more here, as Instructables is easy to manage and show pictures.
Very nice.
Love it! This is awesome! One question I have, for everybody, is how to manage condensation inside? I've slept plenty in the backs of vans while traveling and have noticed on the well used ones that they often have a musk about them that is unfortunate. Any thoughts, aside from leaving doors open, on how to avoid this? In the winter, cracking a window or door doesn't do much to evaporate the mug. Thoughts?
Great comment! This is something we are really aware of and are curious to hear about how others deal with condensation. Our strategy will be to have <strong>good air circulation</strong>. We had someone install a roof fan for us (The FanTastic Vent: http://www.fantasticvent.com/products/model_4000/model_4000.html ). Even in the winter, we will try to sleep with it open (at least a little bit) in order to have new air come in and our own humid air go out. We are also thinking that a little bit of heating before going to bed and in the morning will help with this. Anyone has other thoughts?
heating only moves moisture into the air as hot air can contain more moisture than cold. When it hits cold surfaces it'll condensate. Ventilation is the only way to deal with it, which of course has the double effect of removing the heat as well. <br>The space is too small to use a heat recovery (feel free to show me something that does!) so you'll be stuck with being a bit cold. <br> <br>I can't breathe through my nose, so as a mouth breather the amount of moisture I generate is several times higher than most. <br> <br>If you're installing ventilation I'd install it down low as you'll only be getting rid of the coolest air. Trouble is by installing it low, you risk gusts coming in. <br> <br>Very much catch 22. <br> <br>I'd work on the basis of using it at night and ventilate well in the morning. <br> <br>Carpet of course won't condensate so much and will absorb some of it. You can then air it in the morning with the hope it'll dry out before the evening!
Circulation, circulation, circulation! You can also get a dehumidifier to run for a couple of hours, along with some small fans to dry out the insides really well. The fans push the air around, and the dehumidifier sucks the water into a pan or a bucket. Just remember to empty it!
It looks like simple, yet effective solution! <br> <br>But let me give one advice - just in case: route any wires you need (power, audio, additional lighting etc.) and maybe some spare ones, before covering all with that very nice cedar :-)
Thanks przem! Very good advice, we will indeed pass all our wire before finishing all the walls. We were also thinking of keeping one slat easily removable, where we would hide all the wires behind in order to have quick access.
Also, make a &quot;Wire Map&quot; where you have a sheet of paper with the outline of each panel and where each wire is run, and where they split and whatnot. Pictures help, but having a paper sheet can also help a TON! <br> <br>The more detailed you make this wire map, the more it will help you when you need it most.
Thanks for the advice!
Great Job, I wish we had the time and money to do something similar!
Cool! I did a Transit with Celotex a couple of years ago, managed to get it in all the panels and on the ceiling and makes a hell of a difference.
Sweet! We are really excited to go try it out in the wild in a couple of weeks when we finish off the walls!
Excellent 'ible' well done. I have this same job to do on an old military Land Rover ambulance. I know about that fibreglass wool :) I used to work with the stuff and it is nothing short of vile, especially if you get it into your clothes. <br> <br>A thought. The fibreglass wool 'might' start to sag after a while. I wonder if it might be better installed in a net like structure for the bigger runs? <br> <br>You have mentioned that the van is now a lot quieter :) Is the drumming completely gone from the panels? If not it might have been a good idea to attach thin flat bituminous panels to them before putting the metallised bubble wrap in place. It would just stop that last bit of possible drumming. <br> <br>Well done and thank you :)
We were also very careful in our choice of materials and new the bad reputation of fiberglass insulation. We made sure to wear long sleeve shirts and pants as we did the work, with gloves and masks too. This is also why we insisted on putting a vapor barrier on top of the fiberglass, to seal everything off into the walls so that no dust would come into the cabin once we would be done. <br> <br>As for sagging after a while. I don't think that the small pieces in the top and bottom areas of the walls will move. They are quite tightly placed there and there is not a lot of room to move. For the bigger panels, this is why we used tape to hold it. However, this is only a temporary solution, everything will be hold up more in place once we add the cedar walls - coming up in the next instructables! <br> <br>For sound, we have only done short city trips for now, we will have to really test that out once we go on the highway. Stay tuned! (and thanks for the tip!) <br> <br>Thanks for your comments!
Can you do a temperature difference of outside and inside?
Hi qboid, <br> <br>Great question! We will try to do a quick test once we finish the inside walls with cedar panelling. Stay tuned!

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Bio: I am an industrial designer, an interaction design researcher, a painter, a jeweller, a skier, a camping enthusiast, and I just love to make stuff!
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