Vapor Barrier in a Camper Van Good or Bad?

[@EvilTwin123]

He got right to the video he didn't introduce himself and he didn't ask for thumbs up and subscribes and all that bullshxt....thank you

[@FloridaVanMan]

We are here to share what we learn, keeping these aging vans going. Comments like these mean so much more than thumbs and subs. Thank you for tuning it and letting us know what you think. We have been slow with new videos recently, but more are definitely in the works. With My Best....

[@clifforddavis8084]

Who cares who he is

[@FloridaVanMan]

@@clifforddavis8084 I think that is the point EvilTwin was making. I didn't wast your time telling you about me. Nobody has time for that but it seems most other channels do it AND pitch some unrelated crap at us while watching their content. You won't find that here.

[@ptrkmr]

Thank you so much! I was going to go full vapor barrier and never thought of this. Saved me a lot of time and money

[@theokaralenka]

I am still going. And this video actually did not help, for me it was even more confusing instead :(

[@BenS-v3r]

Your never supposed to have two vapor barriers and since the metal is non-porous it is a vapor barrier. So this guy is 200% right

[@FloridaVanMan]

Yep, two moisture barriers make a delicious mold-sandwich!

[@matthewjswider]

This is an underrated video.

[@FloridaVanMan]

Thank you. We will be revisiting the content of these videos as we grow more experienced. Stay Tuned and please visit the links in our descriptions to give us a boost.

[@rothmaam]

FINALLY. Thank you. After hours of DIY van insulating videos and not being able to commit because of this logic. And no BS. Thank you.

[@3urobob]

That sign off was perfection

[@OniCave]

Great vid. Working on building a vid about condensation / insulation / windows in our 1956 Spartan and how we are solving our issues.

[@dahanler1599]

THIS !!!! Finally, someone said it out loud! All these ppl trapping water inside their RV walls, I get shocked every time I see those reflective vapor barriers with a bunch of holes in them. And then installing their diesel heaters at the entrance, omg.

[@FloridaVanMan]

I say it loud and I say it often... A moisture barrier is GREAT in a home built with sticks and bricks, but it has no good purpose inside a tin can or a steel van.

[@CamperVan-K]

Thanks. I needed this. Just about to start insulating my minivan. Not looking forward to that job. Autumn is here, so it's a bit damp.

[@MichaelLoveridge-vg2be]

Great video, I did think that looking at many van builds and lots leave the inner metal beams, that's why I wanted mine boxed in completely (an insulated box all side, top and bottom) So normal single glass windows are not a barrier? And what about like I said I was doing, a sealed box with an open vent at one end of the roof (with rain top on) and a small extractor fan the other end of the roof, for air flow in vent end and out fan end? Full insulated around the vent and fan outlet.

[@mckennapruett1462]

super helpful !!!

[@jonathanhii3301]

Thanks!

[@FloridaVanMan]

Thank You!

[@gregboyd4321]

Great tutorial! So ur resolve is to try and seal via great stuff, metal tape ecr ect. O of subject u commented on my LM about a wk back. On a 2003 it has a vacuum resinator. Pulled most of my hair out ting to finger the LM out. Well I had a 4 legged toothy critters that had chewed the wiring apart. Rewired and good to go. Tanks 4 ur help. Ciao

[@johnrommelt6560]

What Material (Red Line) do you recommend for any Evap.?

[@gillianhalyk264]

Ok so I get where you're going with this but I have a specific question. I'm in Canada in a climate with temps that go from +40c to - 40c over the course of a year. The trailer is made of sheet metal and steel ribs with a curve where wall and roof meet. Because of the extreme way condensation can occur between the cold metal and the insulation/wall would a vapour barrier with a exterior vent (the curve is going to be empty space which I could take advantage of as a pseudo attic) be a way around this problem? Currently gutting and rebuilding so now would be the time to do it.

[@FloridaVanMan]

If the outer skin of your trailer is non-porous and has no holes or cracks for vapor to get in, that is your vapor barrier. You could vent it like an attic, but this would be venting the existing barrier only to allow the use of a second barrier. The vent to the outdoors will cause much more heat loss, compared to venting* the attic to the trailer interior. You are going to have some moist vapor in a small living space, that's unavoidable. We need to be sure it doesn't get "trapped" where it cannot get back out. Any pocket between two barriers is a "trap", and your trailer skin is a natural barrier unless it is made of wood, bricks or overlapping metal panels that are not seam welded. Vans and Airstream trailers are all seam welded, but cargo trailers are not. Many older RV's and some cargo trailers are skinned with fiberglass panels and sealed with caulk that dries and cracks. This is NOT a vapor barrier, so in this case I would install barrier (and anticipate mold in the wall after a few years).

[@CB19087]

Agree. Today it's minus 4 Celsius in the Uk. I'm mid building my van. The uncovered ribs of the van are dripping wet, obviously, but the carpeted ribs were completely dry. Is there such a thing as making a dedicated dehumidifying surface? Obviously the windscreen is a natural contender but I have a bulkhead. I wonder if leaving the back doors uninsulated that all that water would collect there. Or would it be unnecessary once there's heating installed?

[@FloridaVanMan]

Cold glass makes a great "sacrificial anode**" to draw moisture out of the air but DRY heat is the key. Diesel heaters are great for this. Other tricks* like minimizing moisture in my shower towel helps. I do this by drying a bit with my washcloth and ringing that water out before grabbing a towel that will 'dry' in my van causing airborne moisture (humidity). A laundry basket full of hot dried clothes will draw considerable moisture out of the air in such a small room, so fold clothes in the van, not in the automat. If you must boil water in the van use a whistle top kettle to contain the steam until it can't.

[@nmartin5551]

Once again, you have nailed it, and in less than 23”. A lot less. I wish people could be more succinct. Thanks again! I’m having adventures in Lizard skin ceramic thermal insulation. Made more adventurous by my own idiocy. Probably. I’ll know soon.

[@dahanler1599]

Let us know too please, wish you good luck!

[@TheSololobo]

How did it work out for you using that Lizard skin?

[@nmartin5551]

@@TheSololobo - Well, I’m still (yes, pathetic) working on the van. Using a temp gun, it does seem to have lower heat than the untreated interior. BUT the things I have learned are that if you want to put up a noise dampening product like Fat Mat, you need to do it before you spray. Nothing seems to stick to the dried LS. Second thing I learned was that if you make your own LS (from acrylic paint with ceramic beads), you need to make it a very thick product. I under mixed it.

[@perrymason8471]

My brother used to run a crawlspace mold mildew repair business. He put vapor barriers down in crawlspaces and then scrubbed all the wood and then sprayed the hell out of everything with killx or whatever it was called. Could one use that spray on the walls of the van to prevent mold/mildew? Seems like the best solution is to use wool to insulate, put up your decorative wall and once a year, take it all apart and clean the walls and put it all back. Probably replacing with new wool.

[@FloridaVanMan]

I doubt the stuff used in crawl spaces is something we'd want inside the cabin, even inside the walls. Crawl space is 'outside' the insulated space. The 'best solution' is different depending where you live and travel. Insulation is just one part of preventing mold and mildew. Reducing condensation can be very effective. Easy things like drying my body mostly with washcloth before using my towel. Ringing the washcloth puts several ounces of water into the drain that would otherwise evaporate from my towel. Use of propane inside the van is just pouring water into the air for collecting on any cold surface. And closing or covering your drains will keep water down the drain from evaporating. Anything you can do for a doormat to keep snow outside is obviously going to be huge.

[@cassiophone]

Does this still apply if using a variable vapor barrier such as Intello Plus?

[@harvey123go4]

Hi! great video, I've been trying to get my head around all the information out there regarding vapour barrier and it hasn't really made sense. this has greatly helped. The only thing I can think of is would it help to completely cover the large panels in my van with acoustic matting to put another layer between whatever water vapour makes it through the walls? I intend of being in the van over winter and would like to reduce the potential for ice forming, but then I suppose dry heat would help this too..?

[@FloridaVanMan]

A perfect seal is very hard to get and even harder to make it last forever. Avoid thinking you will keep ALL* moisture out of any space and allow every space a way to dry-out. Complete covering with acoustic mat has proved disastrous for many. As humans, we just can't get it perfect in every corner, and where it is not perfect it traps dirt. Dirt holds moisture, moisture feeds rust and the knee bone is connected to the ankle bone. I mean rust grows out from anywhere it can start. Closed cell spray foam is the best sound reducer and moisture combatant. A breathable wall (any other insulation method) is fine for most situations, but if I were going to be full-time in the van and often in cold climate, professionally installed closed cell spray foam would be a clear choice.

[@jasonwoods50]

Great vid, i have decided to go without a vapour barrier and have loads of ventilation instead. I have a maxxair fan up top and drop out vents down below. I have put foil backed sound deadening and PIR board all round boxed in with wood cladding. My idea is to have some flexible 20mm pipes run into the wall and ceiling behind the cladding and then run them down to the floor to a drop out vent. Thus giving any condensation a way to escape. Will this work or will it encourage condensation? Thanks

[@FloridaVanMan]

Maybe I'm not understanding where/how the pipes will be installed? I don't see how the condensation would collect in the pipes, especially if they are inside the wall and ceiling. I think you have plenty of ventilation and the biggest key is Dry heat like a diesel heater. Propane releases a TON of moisture into the cabin air.

[@tiesb1212]

@@FloridaVanMan Does is also count when it's a diesel water heater?

[@FloridaVanMan]

@@tiesb1212 I don't understand the question. Diesel heaters will exhaust to through a pipe and muffler so they don't add to humidity or condensation.

[@tiesb1212]

@@FloridaVanMan I wasn't sure if there would be a difference. But it is about the exhaust, being outside of the van. Thanks for your reply!

[@AndreasEUR]

0:58 Yes, unless you seal that penetration when installing whatever you're installing.

[@FloridaVanMan]

I've said it before, if you can make a perfectly air-tight seal around every power port and picture hanger... do that! But it better be PERFECT because any leak, even the smallest... will let moisture creep in every time you close a van door. Good luck!

[@AndreasEUR]

@@FloridaVanMan I just watched a video from professional van builders, and they recommend a vapour barrier.. 🤔🤷‍♂️ How are you stopping the moisture that does get in there with no vapour barrier from freezing on the van walls?

[@FloridaVanMan]

@@AndreasEUR "Professionals" are often at-odds with science. They install what they can "sell" to a customer, and talking about moisture *freezing is a wonderfully scary story to help convince you "Everybody else will cheat you." It is total sales-pitch B.S. unless you shower and boil water inside your van, slamming doors to really pump the steam into the wall cavity for a few days and then park it, closed up tight in sub-zero with the heat off. In real life, if your vapor barrier has ANY leaks, it will be worse than no barrier. This is my opinion based on reading non-advertisements like CHBA, PBA & remodeling my own vans. Many professionals never take the opportunity to see how their work holds up over time. They build it and sell it, never see it again. I've taken mine apart and redesigned as my needs changed. Never saw any reason to change the insulation. 4 remodels over 16 years.

[@AndreasEUR]

@@FloridaVanMan kzbin.info/www/bejne/pKjLeoWrnN1ohLs Seem pretty open about the info to me, no hidden agendas.

[@NatashaJBella]

Can you explain what effect does air flow (open windows and Maxxair fan) have on preventing condensation?

[@FloridaVanMan]

Leaving a window open will only help when the humidity inside is FAR greater than the humidity outside. Propane heat produces a ton of humidity so opening a window lets humidity out and cold dry air in. Diesel heaters work very differently and produce dry heat so opening a window will only waste heat unless your van is full of melted snow, cooking steam and wet bath towels. Folks who spend more time in cold areas can probably add some info and I hope folks with experience will comment.

[@TheBluebus17]

Would you recommend painting the wood paneling or plywood on the inside of the trailer, or would this seal and prevent the wood from being breathable and not letting moisture from leaving the inside of the walls?

[@FloridaVanMan]

Paint is a good choice, as it is a semi-permeable barrier that won't trap moisture inside the wall while still preventing most moisture from entering. If you are asking about painting both sides of the board, that seems like more effort than reward. Painting the backside of wall board has pros and cons, like everything else, and whether good or bad depends on your circumstances. In my opinion: It will hide a problem longer but not prevent most problems you might experience inside the wall.

[@utahjohn5480]

Leaks happen (especially on Sprinters). Dry heating (not combustion heating) is also keep to keeping inside dry in Winter.

[@FloridaVanMan]

I can't agree more. The switch from occasional propane heater to Chinese Diesel heater is one of those things... Why didn't I do this sooner?!

[@heidigoescamping3895]

What would you recommend for the floor? I was going to use PIR boards with wood batons and then use aluminium tape to seal it. I'm guessing don't use the aluminium tape so air can circulate? I have saved the ply lining and intended to use reflectix to go over the recycled plastic bottle insulation. I'm now rethinking after watching your video as it makes total sense NOT to add the reflectix and let the van breath. Thank you for making an easy to understand video. I'm just a bit stuck with the flooring now. Many thanks

[@FloridaVanMan]

Especially at the floor, moisture barrier is a bad idea. Moist air is heavy so moisture is more dense near the floor. Spills, wet feet and snowy boots will eventually wet the floor also and a vapor barrier material is not enough to stop that much wetness. Water will get through a tiny leak, behind the barrier and be trapped with only that same tiny leak to evaporate back out. The steel skin of your van is the only vapor barrier you want.

[@gb4939]

Hi, what is your opinion about adding an electric dehumidifier in an insulated van ? Do you think it could create a humidity level as low as in a house? I precise that I plan to buy a big electric station (like Bluetti AC200p or something) so electricity won't be a problem I think.

[@FloridaVanMan]

Household electric dehumidifier produce heat. Electric heat on battery just doesn't work. Dehumidifiers come in all sizes but an average dehumidifier will require more than half the energy of an average air conditioner, which is quite a lot to ask from a portable battery unit like Bluetti. If you are in a cold area I suggest diesel heater and a dozen tips on managing the moisture inside the van including how we use a towel & washcloth after showers. Minimize use of propane, a tray for snowy shoes that drains out or gets dumped, and using the windshield condensation point to extract some moisture, removing it from the van with paper towels.

[@gb4939]

@@FloridaVanMan Thank you very much for the answer and the tips. I am not in a cold area but I have an allergy to dust mites so I need to be careful. And also I suspect that mold can come easily in a car or a van. I thought about plenty of tips. For instance, one of my personnal rule is "never cook inside, no shower inside". And I could go further by saying that any kind of wet clothes or towels will go directly in a special closed box then washed and dried asap. Also I think one of the best solution is to minimize any kind of fabric and to clean very often all surfaces with baking soda, vinegar... So for example, to limit moisture and dust mites, my mattress will be an inflatable electric one made of plastic, same thing for my pillow, and will be washed very often. And so on.

[@NOMAD-LEISURE]

at last! a man that talks sense too many self builders around the world following the greg virgoe method! a guy that builds campers for a MAJOR uk motorhome manufacturer told me that the most important thing in a camper is insulation and AIR CIRCULATION ....

[@ezioauditore3128]

Greg's method is scientifically proven. But it has to be done perfectly to work 100%.

[@NOMAD-LEISURE]

@@ezioauditore3128 yes impossible to do 100%

[@AZRockRunner]

Bill, what is the best insulation for the van? Is it wool?

[@FloridaVanMan]

They all have pros and cons but I believe closed cell spray foam is the best. It bonds to the van metal which reduces road noise better than a van full of KilMat. It forms a solid barrier against moisture that cannot leak or absorb, and it removes easily for future changes or repairs. Anything that prevents air movement inside the wall will have nearly the same thermal value and that total value is based on the thickness of your wall, not the material inside it. Bubble-wrap, foil, mylar and 'radiant barrier' are NOT insulation* and have no useful purpose in a steel can or van.

[@matttrevillien9865]

Hey mate, I'm living in a hot humid climate in Australia, could I use polyester batts and could I put the batts straight in the van wall cavity onto the painted wall panel without any other type of insulation or vapour barrier?? I would really appreciate your feed back as I'm stressing about it haha

[@FloridaVanMan]

Yes, the steel skin of your van is the only vapor barrier you want. As long as you don't have any roof leaks moisture won't be a problem. Any airborne vapor that breathes into the wall can breathe out.

[@matttrevillien9865]

@@FloridaVanMan thanks so much for your reply

[@johnrommelt6560]

Is Closed Cell Spray Foam the Best Insulation the Best for Van?

[@FloridaVanMan]

I believe so. There are many who will argue and most use talking points of ti being done wrong or just falsities like being unable to weld repairs in a van after it has been foamed. I have taken sections of foam out to install support blocks behind the wall and add wires, no big deal at all. I've had an installer spray it too hot in a single pass and bend the metal exterior of the van. yes it was visible if you looked for it but again, no big deal and easy to avoid by doing the job right! A light coat is allowed to expand and cool a few minutes before a second pass fills the remaining wall cavity. One minor drawback is the inability to replace a small area if work is required but almost any other insulation in a small area while the bulk of the van is spray foamed is still a great finished product. NOTHING compares to the sound canceling effect of spray foam bonded to the metal panels, added rigidity to walking on roof, or acts as a vapor barrier so effectively without danger of making a moisture sandwich between two impermeable layers.

[@johnrommelt6560]

@FloridaVanMan So It can be worked on (Welded) even though it has been foamed? The one Video said they won't touch it has been if it has been foamed. Closed Cell doesn't need Moisture Barier?

[@FloridaVanMan]

@@johnrommelt6560 It is easy to remove foam so there is no issue welding, though how many cars have you ever had welded repairs done? That is mostly a muscle-car, hot-rod and restoration thing. In Sprinters I've only seen folks weld footwells and windshield frames where there is no foam even close. Maybe rocker panes but again, several inches away from any spray foam. Vapor barrier is a whole 'nuther topic of mass-debate. Vapor barrier is needed for porous exteriors like wood, brick and even overlapping metal sheets like warehouses. It is NOT needed in a welded panel, sealed box like an automobile. The body is a vapor barrier and a second barrier on the other side of the insulation provides a pocket for moisture to get trapped. Every door slam pulses air pressure in the van that will push humid air through imperfections like switches and fixtures, trapping that moisture between two barriers. Closed cell spray foam provides the best effects of a full vapor barrier on the interior of the wall without the risk of moisture getting trapped in a void between two barriers because there isn't ONE void. With closed cell foam the barrier is comprised of millions of tiny bubbles on the face and no passage between them or the next layer of tiny bubbles that act as a second layer of barrier if the first layer is compromised.

[@johnrommelt6560]

@@FloridaVanMan Thank you very much.

[@muuubiee]

Wouldn't you want a vapor barrier around the sheet metal? Sure, maybe it's supposed to be completely non-porous, but if it's second hand it seems risky to assume that everything is completely intact. I also imagine the vapor barrier has a lower thermal conductivity than steel or whatever the outside is made of, so there'd be less condensation when it gets cold inside the insulation. On the inside I suppose I'd agree, seems reasonable.

[@FloridaVanMan]

If the skin of a van or camper is not water tight, an interior vapor barrier is the LAST thing you need. You do not want to trap moisture between a steel wall and a plastic barrier. Rot will take charge in many forms.

[@stevesy707]

so helpful thank you!

[@arnehin4625]

What if you reverse the process? If the sun heats the van, the moisture will find a way out?

[@FloridaVanMan]

Some* moisture will find a way out. Similarly some* moisture gets into the wall. All* of the moisture from the room does not get into the wall and similarly you will never get all of the moisture out of a wall via small leaks and holes in a vapor barrier. Moisture does not "find a way". It only flows with air and dissipates in stagnate air. Insulation by definition is intended to prevent airflow. No structure should have two vapor barriers with a pocket between them. Your van skin is a vapor barrier, unlike brick & mortar or wood walls, overlapping steel panels or vinyl siding. Our vans are seam welded and form a vapor barrier of steel. This is were they are different from big RV's that are made of fiberglass panels with aluminum corners and trim to conceal the overlapping panels. Those RV's need an interior vapor barrier because the exterior is breathable.

[@dianeibsen5994]

You are one smart dude! Where did you get your education for this stuff?

[@FloridaVanMan]

He he, Google Tech & KZbin U? I've done a LOT of homework and I'm careful about my sources. It is easy to absorb whatever belief is being spouted loudly online, and there are several well-known influencers with misguided beliefs based on "inherited knowledge" that is handed down from fathers, uncles and grandpas who knew something about different construction types. That inherited knowledge often doesn't hold true in our non-traditional construction.

[@alexlandorlandoflorida9754]

I have 2013 Mercedes Benz Sprinter. My back tires are new. They are both at 70 psi. The tires light is on. It does not want to turn off. Now I see the ABS light and 2 other lights on. They are related to the tires. Any ideas?

[@FloridaVanMan]

For the ABS lights on a T1N, we’d start by changing the tail light bulbs to proper spec. However on your 2013, I can only suggest that the TPMS sensors may have gone bad or the antenna (there’s 2x i believe, one in front and one in back) is unable to communicate. Any recent wheel work done lately?

[@alexlandorlandoflorida9754]

@@FloridaVanMan yes, I recently changed the wheels.

[@alexlandorlandoflorida9754]

It was all working fine until I put different wheels on the back

[@FloridaVanMan]

Differently sized?

[@FloridaVanMan]

You may have damaged the TPMS sensors

[@SammyGDude]

At first I was like damn... another old fart, trying to explain things from back in the old days. But now I realize im an old fart, and some people aren't able to make a powerpoint presentation. Good vid, GJ citing some sources. thanks.

[@AndreasEUR]

What are your credentials? Are you a heat/cooling engineer?

[@FloridaVanMan]

My degree and 35 year career is in extraterrestrial communications, bouncing data off a target the size of a school bus at 22,000 miles above our atmosphere. Satellites are solar powered and must withstand unearthly temperature extremes, both hot & cold. So I have done some research on these topics prior to van-life (massively understated). I'm currently building TwoBlue, a van for a friend while Covid restricts my travel to Caribbean international airports where I maintain voice and data links between air traffic control towers via satellite. As you can imagine, these towers are also hot and cold challenges with a great deal of hot equipment. My first sprinter (The Blue Saloon) is my most expensive tool, and only tool that has lasted 16 years & counting. I've lived in it months at a time while working rescue/recovery work post hurricane and other disasters. I've remodeled my van 5 times, researching better methods each time. I've also built-out additional vans for my crew and built 3 for resale since 2017. Not many builders have had the opportunity to repeatedly tear out a van they built 3-5 years ago and inspect the healthy guts. Rebuilding my own van routinely as my specific needs changed form sleeper to cargo/sleeper to office/sleeper, has surely put me in a unique situation to be well knowledged on this topic. I have a base study of insulation techniques in a "tin can" whether that tin can is an orbiting spacecraft or remote terminal shelter on earth, these principals are much closer to van-life than residential construction practices. I'd be happy to verify all of this personally and share stories of my adventures prior to making videos. Send me a message via the coffee link (with a small donation) and let me ramble on until you are convinced. I recognize this reads like I made up the best story I could to justify my position. I assure you every word is true and the only possible exaggeration is the fact that my degree is not from an accredited school. I have held contracts for communications work with Verizon, IBM, EDS, FEMA, The British High Commission, The United Kingdom of Saudi Arabia, currently contracted with The United Nations, but due to covid I am asking for donations for my Friday night pizza. This is my "Will work for food" sign. I'm not a bum, a freeloader, or even disadvantaged. Just a bit unlucky right now as my job may be worst hit when for decades I thought I was recession-proof and adaptive.... Did not see this coming... :O(

[@gaiainanna9069]

so whats the answer plz lol... no barrier?

[@FloridaVanMan]

Correct. No barrier unless you can make a perfectly sealed barrier that expands and contracts with every door slamming. Any leak will be problematic, and every wire, pipe and window is a potential leak.

[@DannyCoolBeanss]

Polyiso board, great stuff, and ac tape good enough? Great vid. To the point, facts to back it up and you sound like Michael Rowe! 😁

[@BobbyFigliola]

He does sound like Mike doesn’t he..?. Agree polyiso would be best so moisture not create mold

[@votehuss4833]

So you're saying that we should double up and put two layers of vapor barrier in there??

[@FloridaVanMan]

...and put a few wet sponges between the layers. :O)

[@ragnaroksangel]

Is that like wearing two condoms?

[@dragonshot7510]

:))))) thank you again

[@bennyhill5938]

whats a quart?

[@FloridaVanMan]

A liter that someone took a chug and put it back. :O) Not sure if you are joking or located somewhere far from me. A quart is just a bit less than a liter. I thought it was odd Canadian reference sources used "quart" and I am not 100% sure which quart they meant. There is something to a 32 ounce quart and imperial gallons with 5 quarts, but I don't THINK these have anything to do with the context of this topic.

[@Cookie.x.monsterr]

So basically I probably shouldn’t vapour barrier as there is no way I’m capable of 100% seal

[@FloridaVanMan]

Correct. A barrier can greatly limit the moisture that gets in, but it also greatly reduces the ability for moisture that does get in to get back out. Paneling, plywood and other common wall surfaces will prevent vapor from passing into the wall cavity, but allow any moisture that gets in there to absorb into the wall board and then dry into the room, very slowly. My experience includes relatively short periods of high humidity in the van, of the course of any given year. if living in the van full time in a humid climate (more humid than Florida) I might* reconsider (probably not).

[@samsurf5967]

@@FloridaVanMan SO what should we use then?

[@samsurf5967]

So what is the solution then for peole that aren't that great with this stuff

[@FloridaVanMan]

Since you cannot make a perfect vapor barrier you are far better off with no vapor barrier except the original metal skin of the van.

[@zambotv8150]

Yas

[@nobrizzle]

So what about vapor retardant layers?

[@FloridaVanMan]

Whatever layers you put in will have air leaks somewhere, somehow. Any moisture that gets in needs a path out. Although, latex paint is a class III vapor retarder rated 1 to 10 perms, so I'm not going to say you shouldn't have any retarder.

[@gregboyd4321]

My bad. A vacuum turbo actuator not the other device

[@r.a.d.u.s.armyret.2904]

Funny.

[@mossymaple]

Mold

[@FloridaVanMan]

Yes, mold is exactly what we are working to avoid. Trapping moisture between two barriers is optimum for mold and we cannot make a perfect barrier to keep all moisture out, so it is better to have no second barrier. The van metal is the first barrier.

[@pathfinder303]

Or mould in proper English.

[@FloridaVanMan]

@@pathfinder303 Is THAT why I keep *misspelling mold/mould?! :O)

[@pathfinder303]

@@FloridaVanMan Yep I'm English and we spell it with a U. I am with you on the vapour barrier, I didn't use it on my Sprinter and I have lived in it for the last two winters and no condensation. I used Rockwool and added carpet liner to all the exposed metal struts as they transfer cold or heat from the outside walls of the van. Greg Virgo as a lot to answer for this.

[@freenorthkorea7317]

Why am I attracted to you lol

[@Syphixxx]

Great video! So it's still worth insulating your van with wool/or another insulation? But it wouldn't be 100% insulated as you will have some gaps at the hard to reach parts.. This would still be the better approach then completely (95%) sealing it? I'm just deciding if I should have insulation at all...

[@FloridaVanMan]

Yes, insulation makes a world of difference, even if it is not perfect. Vapor barrier is different, and if you can't make it perfect you are better off with none.