A great practical demo on how it works! Genius. Thank you Greg! When I did my insulation I got half the van done with VB then winter came. Half my van was dripping where there was no VB, and the other half even though not sealed at edges was bone dry when I cut into it to check. So doesn’t even have to be 100% sealed to be massively effective. If the air doesn’t move through that gap it can’t carry moisture into it. Obv being sealed helps guarantee this. Front half of van started getting mould spots where water droplets kept collecting on top of PIR boards in ceiling. Vapour barrier for the win! Can’t cheat physics!
That’s a brilliant practical example confirmed. Nobody ever backs up their contradictory thoughts with actual proof or science so thank you for another rock solid example
So good, thanks. I’ve put a 7mm foil topped adhesive foam directly on the metal then put insulation on top of that. Do I still need a Vapour barrier on the outside of the insulation, eg over the top of the insulation as well? I see some people put a really thin foil over it. Appreciate your thoughts
@@GregVirgoe I can prove it, watch your video. It proves you are wrong AND you don't know the difference between a vapour barrier and a thermal barrier..If you were right then there would be condensation on the outside of the vapour barrier but there isn't because its not as cold because the insulation is acting as a thermal barrier. That side of the bucket would be dry without a vapour barrier. As for other people not posting proof on here that is an infantile, narcissistic comment, most people do not video everything they do unlike you.
I was watching a video on this subject from a guy who builds campervans for a living. He didn't put a vapor barrier on. I questioned this. He said most professional van builders don't as it causes more issues later on down the vans life.
Greg, you are an absolute treasure for the RV- and Vanlife community! :D Having videos like this is key for people to understand how these things work.
Nice demo but there is a problem ! In theory in a tiny test where you can actually fully seal off the area, yes it works. Vans are not fully sealed nor are they meant to be. Manufacturers have many drain holes, plugs, plastic trim attachments that come all way through into the inside of the van cavities. Thats why vans are designed to drain. Then we go and try to fully seal them up. I do partially agree that adding multiple layers of good insulation and having partial sealed barriers on large wall and roof areas is a good idea. BUT you simply can't full seal up all voids and all areas. So what happens when you try ? You end up sealing in any damp and wet that gets behind your vapour barrier, and it will. Best idea is to use some form of final sheet layer of insulation (vapour barrier) to all large surfaces areas, this prevents "most" of your living space warm moist air hitting the walls BUT then add good ventilation so the easiest path for all that moisture is your roof fans, open windows etc. All the areas you can't fully seal, allow the cavities to still breath. On our van I did 90% seal up with a final layer of sheet insulation behind roof and wall panels. But at the edges where roof and ceiling join, at the lower areas especially at the back of van, the cavities can still breath to dry out if need be. our 2 Maxx Air Fans are either open, or open and running pretty much 24/7. IN below zero in winter if were skiing the roof fans are open and Diesel air heater running to flush moisture and dry the air out. A year later and I have pulled wall and ceiling panels and zero condensation issues. Day to day inside the van we never get condensation, just a little on the inside of the windscreen sometimes. But as far as trying to full seal the van with a vapour barrier, from all the research I've seen vans aren't designed nor should they be full sealed up, vans are nor designed by manufacturers to be fully water proof and fully sealed up behind all the cavity spaces. Thats why there are drain holes all along the van sills.
Problem with this theory is that you might get condensation quickly where you have the steel visible and any water there that tries to espace downwards but get trapped behind the insulation in the walls. Your theory could work if you leave an air gap between the insulation in the walls so the water can follow the steel walls and flow downwards. Also yes the vans are designed to let water out - because they get condensation. If you remove the physical possibility to get condensation, then you won't get any. It's physics laws straight forward. I've built 10 vans now and I'd still say that the best thing you can do is avoid any of the internal air to reach bare metal and the very best method for this is adding Armaflex closest to the steel. Then it's completely impossible to get any condensation at all.
I think this is the way. But you must have an air gap (20mm preferably if using some reflective on foam board) between the steel and insulation. This way the van can get rid of the condensed water like it was designed to. Now I would guess you could easily go for some thin sheep wool between your steel and (actual) insulation. Since it's breathable and mold resistant. It should release any moisture over time. If you go this route I would guess these so called climate vaper barriers are the way to go. They control the flow rate a bit better to keep a nicer climate inside the van? Question mark? (I am no expert, just learning and reading about this topic)
Wrong, cavities are only in doors with WIND down windows, in every van I know of....No drain holes in my Van apart from front doors, they are designed to release water as water enters from the winding window...Trim Attachments on any van should be sealed especially sidestrips, look at umpteen youtube videos about sealing factory roof plugs, and side trim!!!!Major issue with vans, they need trim properly sealed regardless of insulation or a build out..Do proper research! Not sure what Van you have but it Ain't a Merc, Transit or others I know of..
@@Namdor2012 After 1 1/2 years and multiple sub zero ski trips I have pulled down my ceiling and wall panels and pulled back the 2 layers of Thinsulate, and the solid sheet (foil radiant layer) and what did I find ? No sign of any condensation, no water or condensation damage, no mould or mildew. Dry as a bone. I do not have a vapour barrier ! A cavity is just a "space" the whole van behind the walls, ceiling are cavity spaces. I do have strong air barriers and plenty of active ventilation and airflow 2 x Max Air fans open or running 24/7 You don't need a vapour barrier. Allowing a van to breath and plenty of airflow, and good insulation, is the key to stopping condensation. I have seen many a van that tries to seal up everything and they pull back walls etc to find damp, mould, wet insulation.
Thank you Greg this is the way I've done my insulation on my build and so much rubbish about the vapour barrier. I'm about to start electrics and your videos are a blessing 🙌
Well done Greg. I’m going to share this video with my van builder friends! Edit: There’s also the effect of increased relative humidity due to cooking, heating and breathing. Good reason for proper ventilation as well. Thanks again for another great van build video. IMHO, you’re one of the best on YT!
Nice one Greg. I have followed your advice on 3 van builds after seeing that you obviously know your onions.. I would be interested in seeing the test again using insulation but no vapour barrier as I know many builders put in insulation with no barrier..
The building philosophy years ago, was to put polythene (non-permeable) over the insulation (usually Rockwool or fibreglass (itchy stuff) and then plasterboard over it. But, any gaps within the plasterboard, plaster failure (plaster can provide air tightness layers too), the polythene can sweat at the back and the moisture will run/drip down and start the erosion process of your timber studs, so, that's why, if you want increased air tightness within your house, you use an air tightness member called Intell and then tape up the seams/joints with Tescon Vana air tightness tape.
Thanks for the video!!It would be interesting to see how much moisture would get in if there was a hole in the vapor barrier. It would have to be a long term test. I used the same type of barrier, but when adding finished wall, I know there are some screw holes through the barrier. Hopefully the small amount of moisture that gets through will do no harm.
@@laurenmichele2029 you seal around any recesses or cables with foil tape as I have shown in my build videos. A little care and attention is all that’s needed. 😊
Great experiment Greg, very clear. I'm eagerly awaiting the next addition with insulation on the bucket but no vapour barrier for the comparison between vapour barrier or no vapour barrier. The time and effort you put into these videos is really appreciated.
Thanks for this. Just started building my van and your videos and guides are by far the best. Always good to learn from someone who genuinely knows what they're talking about! 👏👏👏👍
I'm all for vapour barrier and have installed it, the experiment has proved the need for insulation. It would have been interesting to see a 1/3 of the bucket with just insulations 1/3 with vapour barrier 1/3 bare metal. Cheers for the video anyway 👍
Hi Greg, it was great to finally chat to you in person after following you for nearly 4 years. Hope you had a great Camp Quirky. You will need a rest after meeting so many people. Regards, Steve.
Great video. I cant see how you can 100% seal your van. It would be interested to see if you would put small hole in, to demonstrate if you put some screw hole in by accident when you are working on your van
Firstly screws don’t leave holes unless you take them back out? It’s very easy to seal plastic trim clips, tape joins and edges, tape behind sockets and lights. It’s not hard to do. 👍🏼😊
I live in Tasmania and when I commenced my van build I had the luxury of watching your van build videos Greg. Hence my Sprinter has a complete vapour barrier and is well insulated. This demo video just impresses how vital those two components are when well fitted. Thanks mate. 👍
Hi Greg thanks for another great video👍. Just watching a new channel called Ame in a van and she talks about this guy who is an absolute legend who she watched whilst building her van. That guy is you.👍
Did exactly this on our build thanks to your van build series. Huge thanks! The van is bone dry and stays cool in the sun and warm in the cold. So we’re very happy campers. Cheers Gregg. Would never have known what to do without you 👍🏻
That is an absolutley brilliant Demo Greg...i have converted 3 vans in my time and always carry out thermal insulation and vapour barrier as standard. Great video.
Excellent demonstration of how to form a closed cell installation by using insulation & vapour barrier- I do smile when I see comments about using vapour barrier & the reasons why you shouldn’t use it. Yet they use celotex on there roofs or suggest ventilation- you just need to sit in a back of a van when it’s pouring with rain outside to see the condensation forming like a river… - no amount of ventilation will stop it forming, unless you’re sleeping with all the doors an windows open. Not very stealth or safe! 👍 Thank you for sharing the holy grail of Vapour barrier debates! 🎉🎉
Your van build videos are constant source of reference Greg, the difference adding just the PIR board to the roof of the van has been significant which convinced me I was going the right way. There's been a lot of chat around vapour barriers on the forums, this video should convince any doubters. You will spend thousands getting the interior how you want it, and have it all undone in a matter of months by ignoring this. Great work as always Greg 👍🏻
I totally agree with what you say Greg. I was interested to see what VW did in there California, when I inspected one there was no insulation or vapour barrier behind the sink cupboards and the bare skin of the van was visible, this was on a 2018 California. I did hear that Vw say the output of the diesel heater over comes any issues. When i did my Vw camper I didn’t use any insulation I just rely on the diesel heater, obviously it’s worked much harder and very very wasteful on fuel, but in the morning after a winter camp the exterior of the van like the inside is bone dry. If I used my van for longer than weekends then I would have adopted the vapour barrier and insulation approach. Great video as always.
You have to keep the entire metal fabric of your vehicle above the Dew point temperature and provide loads of ventilation too but I guarantee it would cost an absolute fortune every night and would not work over winter when it’s really cold. You are paying ridiculous money for that sub standard installation too 😳
A really good demonstration. I've noticed a lot of US based van builders don't install vapour barriers, so have wondered how necessary it is. Now I know and will ensure I fit one when I get around to doing a build.
Most good experiment and explination of the need for vapour barriers. would be need to see the same experiment with out the vb just with the insulation?
May I suggest you do the same experiment, but without the vapor barrier material? Tape up that same insulation material on one side and add the ice/water and show what happens.
I'd also like to see how just a vapour barrier (with a couple of millimetres of foam backing or the 'bubble wrap' type) without any additional insulation performs. In a small volume, such as a van, I'm wondering whether a thick layer of insulation is particularly pragmatic, considering that you need almost constant airflow. At night the duvet is your main source of insulation.
agree, would like to see how just a adhesive backed insulation works on its own, like dodomat superliner. this test is proving insulation + vapour barrier.
I would like to see the same experiment with a small hole in the vapour barrier hat has been unsealed caused in a practical case through passing a cable though the vapour barrier and failing to seal it.
Hi Greg I’m just about to start a van motorhome conversion and have just watched your video on vapour barriers! I’m totally on your side. If you get a chance please look on RUclips at a Vanology Conversion video on Not to have Vapour a barrier!!! 16 January 2024 They even leave gaps in the insulation to let the air in? Let us know what you think??
I'm wondering, what is your view on the topic of penetrations in the vapor barrier, for example, where LED, sockets, etc. pass through it? Surely, these types of "penetrations" cannot be fully isolated by a vapor barrier and thus vapor will get through them.
Hey Greg, your video saved me IMMEASURABLE time researching this topic. Thank you for giving me hours and hours of my life back! One question that maybe you know the answer to: what impact (if any) do side and rear windows have on insulating a van? Is it better to build out a van with no windows from an insulation & vapor barrier perspective, or does it not matter much? I'd expect having thin panes of glass around the van would diminish the effectiveness of the insulation and vapor barriers, but I hope this wouldn't completely nullify the insulation.
When you cut windows in those areas have a greater heat loss as they are no thermally efficient like insulation but it doesn’t affect the installed insulation or vapour barrier. Double glassed campervan style windows are thermally better. With single glass you may get a little condensation on the glass but keep the van warm and well ventilated and that will be a minimum. Best wishes.
That is amazing, and you have certainly , proofed your point. I have a big issue on a work van , with moisture collecting on the inside roof , and this is because I am running an engine to generate PSI, constantly during the day , in order to do my job. Which will always be done with side and back doors open. I would be grateful if you would list the materials you used.
There is a details playlist for the build of my van showing each stage. I used PIR insulation slab for the floor and roof and side panels and I recommend Diall recycled plastic loft insulation for all the awkward areas and stuffing in beams. Seal over everything with double foil bubble wrap as a vapour barrier 👍🏼😃
Great experiment I always wanted to know if this theory works, and you proved that it does work " vapor barriers do work when done correctly" Thank You for proving this theory 👍🇺🇸
Yes they do work and it why everywhere in industry when you have cold metal surfaces they are insulated and vapour barrier applied to prevent condensation. It’s not hard to do either.
Hello Greg your comments are turned off in your last video I don’t know if you new that. Ame in a van gave you a really good plug last night :). She converted a transit using your good videos 👍
I am 100% with you on the importance of the vapour barrier but I was a little perplexed to see you use those stick on steel spike things in your previous roof insulation video for holding the Celotex boards up, because what you've done there is introduce a thermal bridge into your nice efficient insulation. I'd be interested to see you do this experiment above with one of those spikes installed in the middle of your insulation, and see if you get a little spot of condensation around that tophat that sits on the outside of the insulation and the end of the spike. Van's are full of thermal bridges, it would be hard to get rid of all of them, but introducing more seems unnecessary.
You need to repeat the experiment with just the insulation and no vapour barrier now Greg. It brings balance to the test then. 👍🏼. By the way I’m a believer in vapour barrier 👌🏽
Great experiment. Couldn't remember if I put the reflective barrier or insulation on first - knew I could rely on GregV to provide the correct answer! cheers :D
Thanks, Greg - another great demonstration! Moisture is not your friend. Proper insulation and a sound vapour barrier are as important as a proper ventilation concept to keep the ambient moisture at acceptable levels. This also goes hand in hand with CO2 management to maintain good air quality in your van. Mandatory info for all van builders!
I believe a vapour barrier is vital for a van build in the UK or any cold climates. Even if you make mistakes and leave a few small gaps/holes I believe although condensation will occur it will be far less of a problem compared to no vapour barrier at all.
You're preaching to the converted here, but I really hope this provides support to those who still doubt the benefits of a vapour barrier. Great to see you at Camp Quirky, I'll be sporting your famous 'Half Hour' t-shirt very soon... 🙂
When you peel the instulation I can see some small droplets in the bottom part of the can and also on the left side (few small dros). Is that normal? Thanks Greg, you are the superman of insulation!
Another great video Greg. I’m just starting out on our conversion, and taking your advice from your build videos. First one being, insulation and vapour barrier are essential. 👍
Have you covered in any of your videos the specifics of driving on the continent? Do you have a process for transitioning? What do you do about your headlight alignment?
Hi Greg. A good presentation but I have an issue with the way you did it. Your experiment shows the difference between having INSULATION + VAPOR BARRIER vs not having both. To show that vapor barrier works, you should have insulation on both sides and the vapor barrier only on one side and then see the difference. What do you think?
Be interesting to see what would happen with just insulation and no vapour barrier. Maybe do the same experiment but hold the insulation on with chicken wire. Great video though Greg as all ways 👍
Closed cell foam like armacell might show some condensation when it's not entirely glued to the shell. There could be rust between shell and insulation. But if it's glued on well, it's like a barrier by itself.
In reality you don’t drill and leave holes when you fix stuff to the walls you use screws which are plugging their own penetration so there is no hole there. ☺️😎
Hi Greg. I’m a very tight budget and I’m thinking rather than spending €200 on silver bubble wrap could I use something as simple as PVC bin bags. Thank you for your very informative videos and looking forward to more. Regards Noel
let's say I have been collecting van building video tips for a year or two now and this particular video popped back up inside my mind after seeing somebody apply spray foam to an interior (it looks good) - i recalled "oh but don't forget the vapor barrier") :)
Am I right in thinking that closed cell foam doesnt need an additional vapour barrier on top because itself it is non permeable? As long as the layer is thick enough and the joints are foil taped? Thanks!
Good job. I've seen many videos of people building their camper vans with no vapour barrier and that made me sad. Mold is toxic, rust is a pain in the ass.
Hi, I am worried about water moisture is in the van panels getting locked in and not circulating out . I have a crafter and they are known to leak from the outside trims . What’s you view on this Greg
Question. Is it possible to know if moisture has collected inside a moisture barrier? Eg via a conductivity meter, or by adding a sensor inside the barrier, or something else.
@@GregVirgoe unfortunately we're can't all be as perfect, and it's sure to give me nightmares leading to permanent mental trauma, and it'll all be your fault Greg ;)
I've just insulated my van with Dodo mat liner then the plastic bottle white insulation in a roll then another thinner liner from dodo Matt on top then sealed all edges and joins with that silver insulation tape, have I put in a vapour barrier ?
Great video! Thank you for sharing! I'm curious what you or others think about "professional" spray foam insulation. Seems that would seal things pretty tight. Pros? Cons? Thanks!
Yes it’s an excellent insulator and will solve all condensation issues. Only cons are can be messy install and cleanup plus it’s a permanent solution and easily removed if needed.
You are an absolute genius 🤓. Your videos are all amazing 🤩. I am trying to watch all of them , before I buy my next van for a conversion. Thank you so much for all the efforts and all the valuable information that you introduce into your amazing videos. Honestly, I would trust no one to do the conversion of my next van , but you my friend. Great job 👌👍 I hope you can do it for me 😉
That was a excellent experiment Greg..............definitely worth spending time getting you insulation right on your van first...........stay safe.........thanks for sharing
Do you insulate doors as I've recently seen a video showing why it's a bad idea insulating doors as doors normally have windows and obviously handle where water can enter inside the panel to solve this issue the doors have drain holes in them so if you insulated you would have a problem
No insulation in the doors as you say the opening windows allow water down inside the doors plus so many mechanisms in the it would be impossible to do it without jamming up the doors.
Great demonstration. If air is an affective insulator itself wouldn't it make sense to just install a vapor barrier over the panels of the van leaving a gap of air in between your barrier and wall?
No the insulation value of air is very low and a cavity doesn’t vary with thickness either. Insulation no matter what form is always going to be better than just air. 👍🏼😊
@@GregVirgoe ahh thats makes much more sense. I guess i over estimated the properties of air! Thank you for such in depth educational van videos, it is greatly appreciated
Thanks Gregg. A Great demonstration. Do you have a plan for further practical demonstrations like using Insulation only without the vapour barrier ? This is a common alternate I hear about. Thanks again.
On my van I’m thinking of using the recycled plastic wool then covering over with a thermal liner, how would I go about fixing the ply wood layer on to the thermal liner? Would screw holes then cause condensation potentially?
I have learnt so much from this video and your others. Saw you at Stratford upon Avon doing a talk to the punters. Learnt much there as well. Cheers Greg.😊
Thank you for sharing, that's a great experiment. I have a question in regards to living in Australia. The majority of the places I go to are warm to hot/dry/humid heat. Is it the same deal for those conditions, is there an experiment that can be done to test that out? I look forward to hearing what is the better option for hot conditions, thanks in advance.
Great demo Greg, I'm currently doing a van conversion on a Citroen Relay and I have been diligently applying a vapour barrier, the issue I have is that I need access to the nuts that hold the rear light clusters in place, has anyone managed to seal off this area but still leave access for changing light bulbs?
Hi Greg , I have just insulated and about to move on. I'm flummoxed at the minute whether to put vapour barrier then framing , or framing behind the vapour barrier ? And should the electrics go infront or behind the vapour barrier ? Lucy
Hi Lucy. It’s best to put your vapour barrier over you insulation and your van then framing and cladding on top. If you have space in the depth of the framing you can put wires there but be careful not to screw into them. Or you can put wires in conduits in the van walls. Make sure to seal around any holes for wires with foil tape. Hope that helps 👍🏼😊
Such a great video! I’m in the middle of a build and the thought of moisture stopped me In my tracks. Glad to have found you on RUclips! Side note: Have you or anyone dealt with water build up in the rocker panels? I have run into this issue with Ram promaster 2500. I’m lost with how water keeps getting in. 🤷♂️ ty for all your effort in each vid!!
I’m aware that there is a poor design on the scuttle below the windscreen that allows water to pour onto the engine bay. Make sure any drain holes are not blocked with debris, any rubber bonnet seals are intact. Use a bit of DW40 on head as water repellent. I have known others to cover the engine bay with on combustible plastic sheet to keep water away. Hope some of those help you 👍🏼
Fantastic video Greg! Would really appreciate your thoughts on the following if I may. It is fairly easy to continuously seal the cargo area. However, in my Renault Trafic, the A, B & C pillars are all connected across the top due to how they create the bodywork. So a void across the top, which all pillar voids merge into. It's easy to seal up the C pillar behind the sliding doors. The B pillar though, well thats got the seat belt mechanism inside so no way to seal where the belt is at shoulder height and the reel at the bottom has to come up the pillar. A pillar has an opening under the dash corner. So two questions here :-). 1: Stuffing the pillar voids with insulation as best as is possible? (getting it in there effectively still eludes me, i've thought about blowing little wads in with an airline...) 2: Vapour barrier it as much as is possible? even though there has to be an opening for the seat belts? EDIT: More thoughts from me! Given the pillars are subject to thermal conductivity from the outside skin, then stuffing them with insulation will have negligible effect right? It will stifle airlfow I guess, but not vapor over time? Then given I cannot for a 100% barrier on the B pillar because of the seatbelt, surely the B pillar is still in its original situation, vapor in, condensation will form on the outerskin in the right consitions, dripping down into the sill? & that pillar is connected to the C pillar via the horizontal cavity across the roof line.
There nothing you can do with the seatbelt pillars or a lot of the cab floor or doors. You can close up the top beam section with some closed cell foam to seal it from the rest of the van. Minimising the potential for water to build up 👍🏼😃
Super series on building a camper van Greg! Really enjoy it. About to start isolating my Ducato with PIR isolation and Armaflex. The question I still have is when we use PIR isolation on the walls and the roof/floor there will always be an air gap between the steel and the isolation in opposite where Armaflex will leave no air gaps. Will there be condensation between the isolation and the steel? On one hand I think no, because the temperature on both sides of the steel is approx equally. Am I right? We will make mistakes on our first van build but would prevent one with isolation. Looking forward to your response.
Excellent demonstration Greg. There's a tough crowd here in the comments, but the physics don't lie. They have two choices, use a vapor barrier or use a dew point meter and always keep the ambient temperature above dew point lol.;)
Doors with handles and locks you need to put your insulation in plastic bags as the door still needs to drain from water ingress. Door frames can be packed with wool from and holes, wrapped with thin insulation layer and carpeted.
@@GregVirgoe Thanks Greg.. I meant the likes of the top frame of the sprinter sliding door ( around window I fitted ) and the likes of the door pillars behind driver and passenger seats ,rear double door pillars plus top sections of rear doors. Thanks
Facts over fiction i’d say Greg. You’re akin to Ronseal … does exactly what it say in the tin👍 PS great to see you imparting your time serves skills at Camp Quirky this last weekend too 👍 Cheers
I’m happy to give my time and expertise for free so that everyone can benefit by doing the right thing and not be sidetracked by mis information and speculation.
Thanks for this, Greg. We've done a vapour barrier, following your instructions mostly. I was wondering how worried we should be about small holes? We've screwed through it quite a lot, and I know if there are screws tight in that's not a problem. But what happens if you've accidentally made a tiny hole is your vapour barrier then dead?
You see it a lot in the US with young couples making and selling vans not installing a vapour barrier. It's less than a days work to fully line a van with a vapour barrier.
If you plan to only use it in very hot climates it’s not an issue but as you rightly say it’s so easy to do why not fit regardless and have peace of mind.
@@GregVirgoe Ok Thanks, one more question... I´m using closed cell foam boards and filling the gaps with normal cheap urethane foam. Is it enough if I only use aluminium tape to those urethane gap parts or do I need to cover the whole walls with the vapour barrier plastic?
wooden struts to frame the van before or after vapour barrier? thats what is doing my head in lol as vapour barrier makes it difficult to attach stuff to van
You can put your timber inside or outside the barrier it makes no difference. There will be no moisture so there is no problem. Also no problem fixing either as any screws are themselves a plug so there are no holes.
A great practical demo on how it works! Genius. Thank you Greg! When I did my insulation I got half the van done with VB then winter came. Half my van was dripping where there was no VB, and the other half even though not sealed at edges was bone dry when I cut into it to check. So doesn’t even have to be 100% sealed to be massively effective. If the air doesn’t move through that gap it can’t carry moisture into it. Obv being sealed helps guarantee this. Front half of van started getting mould spots where water droplets kept collecting on top of PIR boards in ceiling. Vapour barrier for the win! Can’t cheat physics!
That’s a brilliant practical example confirmed. Nobody ever backs up their contradictory thoughts with actual proof or science so thank you for another rock solid example
So good, thanks. I’ve put a 7mm foil topped adhesive foam directly on the metal then put insulation on top of that. Do I still need a Vapour barrier on the outside of the insulation, eg over the top of the insulation as well? I see some people put a really thin foil over it. Appreciate your thoughts
@@GregVirgoe I can prove it, watch your video. It proves you are wrong AND you don't know the difference between a vapour barrier and a thermal barrier..If you were right then there would be condensation on the outside of the vapour barrier but there isn't because its not as cold because the insulation is acting as a thermal barrier. That side of the bucket would be dry without a vapour barrier.
As for other people not posting proof on here that is an infantile, narcissistic comment,
most people do not video everything they do unlike you.
I was watching a video on this subject from a guy who builds campervans for a living. He didn't put a vapor barrier on. I questioned this. He said most professional van builders don't as it causes more issues later on down the vans life.
Better to have some breathability if moisture does get in
Greg, you are an absolute treasure for the RV- and Vanlife community! :D Having videos like this is key for people to understand how these things work.
In an ideal world we'd all have a Summon-A-Greg app, which sends a robotic Greg to just do the job for us.
I really appreciate that, thank you 🙏🏼
Nice demo but there is a problem !
In theory in a tiny test where you can actually fully seal off the area, yes it works.
Vans are not fully sealed nor are they meant to be. Manufacturers have many drain holes, plugs, plastic trim attachments that come all way through into the inside of the van cavities. Thats why vans are designed to drain. Then we go and try to fully seal them up.
I do partially agree that adding multiple layers of good insulation and having partial sealed barriers on large wall and roof areas is a good idea.
BUT you simply can't full seal up all voids and all areas. So what happens when you try ? You end up sealing in any damp and wet that gets behind your vapour barrier, and it will.
Best idea is to use some form of final sheet layer of insulation (vapour barrier) to all large surfaces areas, this prevents "most" of your living space warm moist air hitting the walls BUT then add good ventilation so the easiest path for all that moisture is your roof fans, open windows etc.
All the areas you can't fully seal, allow the cavities to still breath.
On our van I did 90% seal up with a final layer of sheet insulation behind roof and wall panels. But at the edges where roof and ceiling join, at the lower areas especially at the back of van, the cavities can still breath to dry out if need be.
our 2 Maxx Air Fans are either open, or open and running pretty much 24/7. IN below zero in winter if were skiing the roof fans are open and Diesel air heater running to flush moisture and dry the air out.
A year later and I have pulled wall and ceiling panels and zero condensation issues. Day to day inside the van we never get condensation, just a little on the inside of the windscreen sometimes.
But as far as trying to full seal the van with a vapour barrier, from all the research I've seen vans aren't designed nor should they be full sealed up, vans are nor designed by manufacturers to be fully water proof and fully sealed up behind all the cavity spaces. Thats why there are drain holes all along the van sills.
Problem with this theory is that you might get condensation quickly where you have the steel visible and any water there that tries to espace downwards but get trapped behind the insulation in the walls. Your theory could work if you leave an air gap between the insulation in the walls so the water can follow the steel walls and flow downwards.
Also yes the vans are designed to let water out - because they get condensation. If you remove the physical possibility to get condensation, then you won't get any. It's physics laws straight forward. I've built 10 vans now and I'd still say that the best thing you can do is avoid any of the internal air to reach bare metal and the very best method for this is adding Armaflex closest to the steel. Then it's completely impossible to get any condensation at all.
I think this is the way. But you must have an air gap (20mm preferably if using some reflective on foam board) between the steel and insulation.
This way the van can get rid of the condensed water like it was designed to.
Now I would guess you could easily go for some thin sheep wool between your steel and (actual) insulation. Since it's breathable and mold resistant. It should release any moisture over time.
If you go this route I would guess these so called climate vaper barriers are the way to go. They control the flow rate a bit better to keep a nicer climate inside the van? Question mark? (I am no expert, just learning and reading about this topic)
Wrong, cavities are only in doors with WIND down windows, in every van I know of....No drain holes in my Van apart from front doors, they are designed to release water as water enters from the winding window...Trim Attachments on any van should be sealed especially sidestrips, look at umpteen youtube videos about sealing factory roof plugs, and side trim!!!!Major issue with vans, they need trim properly sealed regardless of insulation or a build out..Do proper research! Not sure what Van you have but it Ain't a Merc, Transit or others I know of..
@@Namdor2012 After 1 1/2 years and multiple sub zero ski trips I have pulled down my ceiling and wall panels and pulled back the 2 layers of Thinsulate, and the solid sheet (foil radiant layer) and what did I find ?
No sign of any condensation, no water or condensation damage, no mould or mildew. Dry as a bone.
I do not have a vapour barrier ! A cavity is just a "space" the whole van behind the walls, ceiling are cavity spaces.
I do have strong air barriers and plenty of active ventilation and airflow 2 x Max Air fans open or running 24/7
You don't need a vapour barrier. Allowing a van to breath and plenty of airflow, and good insulation, is the key to stopping condensation.
I have seen many a van that tries to seal up everything and they pull back walls etc to find damp, mould, wet insulation.
@@rbrown Okay so who is right here?? I want to convert a cargo trailer into a camper 😩
100% agree with you on vapour barriers. Great vid 👍
Thank you both 🙏🏼🤩
Smug grinning from me as I followed his advice. I can't tell you how many videos I've watched that said you don't need it.
Thank you Greg 👍
I know I’m trying my best to help point people in the right direction
well done that man, you have done me a 100 % big favour. I have now decided how to insulate and vapour seal my van. Thank you.
I’m glad you found that to be useful. Thanks for watching 👍🏼
Thank you Greg this is the way I've done my insulation on my build and so much rubbish about the vapour barrier. I'm about to start electrics and your videos are a blessing 🙌
I’m pleased that you followed my method. You will have no problems in the future. Best wishes 😊
Well done Greg. I’m going to share this video with my van builder friends!
Edit: There’s also the effect of increased relative humidity due to cooking, heating and breathing. Good reason for proper ventilation as well.
Thanks again for another great van build video. IMHO, you’re one of the best on YT!
Thank you very much. Really appreciate your support 👍🏼😃
Nice one Greg. I have followed your advice on 3 van builds after seeing that you obviously know your onions.. I would be interested in seeing the test again using insulation but no vapour barrier as I know many builders put in insulation with no barrier..
I will do that as a follow up video.
👍🏼😃
Thats exactly what I thought jonny. Get it done Greg as that will be the one that will get people thinking.
The building philosophy years ago, was to put polythene (non-permeable) over the insulation (usually Rockwool or fibreglass (itchy stuff) and then plasterboard over it. But, any gaps within the plasterboard, plaster failure (plaster can provide air tightness layers too), the polythene can sweat at the back and the moisture will run/drip down and start the erosion process of your timber studs, so, that's why, if you want increased air tightness within your house, you use an air tightness member called Intell and then tape up the seams/joints with Tescon Vana air tightness tape.
Thanks for the video!!It would be interesting to see how much moisture would get in if there was a hole in the vapor barrier. It would have to be a long term test. I used the same type of barrier, but when adding finished wall, I know there are some screw holes through the barrier. Hopefully the small amount of moisture that gets through will do no harm.
Screws are usually fine, the screw self-plugs the hole
As Paul rightly says a screw does not leave a hole 🕳😃👍🏼
@@GregVirgoe what about light fittings
@@laurenmichele2029 you seal around any recesses or cables with foil tape as I have shown in my build videos. A little care and attention is all that’s needed. 😊
Great experiment Greg, very clear. I'm eagerly awaiting the next addition with insulation on the bucket but no vapour barrier for the comparison between vapour barrier or no vapour barrier. The time and effort you put into these videos is really appreciated.
I might have to put these in a dedicated playlist. 🤔🤩
Thanks for this. Just started building my van and your videos and guides are by far the best. Always good to learn from someone who genuinely knows what they're talking about! 👏👏👏👍
Thank you and best wishes for your build.
I'm all for vapour barrier and have installed it, the experiment has proved the need for insulation. It would have been interesting to see a 1/3 of the bucket with just insulations 1/3 with vapour barrier 1/3 bare metal.
Cheers for the video anyway 👍
I’ll do another one just with insulation to show that condensate too 👍🏼😃
It would be interesting to see behind 'just' vapour barrier too. For those spots where you can't get any insulation.
Great vid Greg.
Hi Greg, it was great to finally chat to you in person after following you for nearly 4 years.
Hope you had a great Camp Quirky. You will need a rest after meeting so many people.
Regards,
Steve.
It was extremely busy but also great to meet so many new people that follow our channel. Thank you Steve 👍🏼😃
Great video. I cant see how you can 100% seal your van. It would be interested to see if you would put small hole in, to demonstrate if you put some screw hole in by accident when you are working on your van
Firstly screws don’t leave holes unless you take them back out?
It’s very easy to seal plastic trim clips, tape joins and edges, tape behind sockets and lights.
It’s not hard to do. 👍🏼😊
I live in Tasmania and when I commenced my van build I had the luxury of watching your van build videos Greg. Hence my Sprinter has a complete vapour barrier and is well insulated. This demo video just impresses how vital those two components are when well fitted. Thanks mate. 👍
I’m very pleased you did the right thing. Well done 👍🏼😃
Hi Greg thanks for another great video👍. Just watching a new channel called Ame in a van and she talks about this guy who is an absolute legend who she watched whilst building her van. That guy is you.👍
Ame and I chatted a few times when she was building her van 🚐
I’m so pleased she is now living her dreams and enjoying life 😃
Did exactly this on our build thanks to your van build series. Huge thanks! The van is bone dry and stays cool in the sun and warm in the cold. So we’re very happy campers. Cheers Gregg. Would never have known what to do without you 👍🏻
That really makes me happy 😊 I know your van will be safe now
And I’ve just noticed I spelled Greg with two g’s… face… hand!
@@0i-di no problem I’ve had much worse 😂👍🏼
That is an absolutley brilliant Demo Greg...i have converted 3 vans in my time and always carry out thermal insulation and vapour barrier as standard. Great video.
Then you can sleep peacefully at night knowing you’ve done a first class job 👍🏼😃
Excellent demonstration of how to form a closed cell installation by using insulation & vapour barrier- I do smile when I see comments about using vapour barrier & the reasons why you shouldn’t use it. Yet they use celotex on there roofs or suggest ventilation- you just need to sit in a back of a van when it’s pouring with rain outside to see the condensation forming like a river… - no amount of ventilation will stop it forming, unless you’re sleeping with all the doors an windows open. Not very stealth or safe! 👍 Thank you for sharing the holy grail of Vapour barrier debates! 🎉🎉
Thank you for your support 👍🏼😃
This comment made me laugh out loud, thinking because its got similar properties a bit of celotex is the same as a vapor barrier !!
Your van build videos are constant source of reference Greg, the difference adding just the PIR board to the roof of the van has been significant which convinced me I was going the right way. There's been a lot of chat around vapour barriers on the forums, this video should convince any doubters. You will spend thousands getting the interior how you want it, and have it all undone in a matter of months by ignoring this. Great work as always Greg 👍🏻
Exactly that. Thank you 🙏🏼
I totally agree with what you say Greg. I was interested to see what VW did in there California, when I inspected one there was no insulation or vapour barrier behind the sink cupboards and the bare skin of the van was visible, this was on a 2018 California. I did hear that Vw say the output of the diesel heater over comes any issues. When i did my Vw camper I didn’t use any insulation I just rely on the diesel heater, obviously it’s worked much harder and very very wasteful on fuel, but in the morning after a winter camp the exterior of the van like the inside is bone dry. If I used my van for longer than weekends then I would have adopted the vapour barrier and insulation approach.
Great video as always.
You have to keep the entire metal fabric of your vehicle above the Dew point temperature and provide loads of ventilation too but I guarantee it would cost an absolute fortune every night and would not work over winter when it’s really cold. You are paying ridiculous money for that sub standard installation too 😳
A really good demonstration. I've noticed a lot of US based van builders don't install vapour barriers, so have wondered how necessary it is. Now I know and will ensure I fit one when I get around to doing a build.
The only time you wouldn’t need one is if the climate you was living in was always very warm above the dew point. 👍🏼😃
@@GregVirgoe That did occur to me as a reasonable situation.
Great video Greg. And great to meet you yesterday and took the time for a chat. 👍
Thank you for coming to say hello. It was great to meet you too 😃
Great demonstration.. but would it be possible to include an edit where you just have the wool insulation and not the aluminium wrap?
Yes I think I will revisit this one with different insulation build ups 👍🏼😃
Most good experiment and explination of the need for vapour barriers. would be need to see the same experiment with out the vb just with the insulation?
Yes I will do that for completeness. 😊
May I suggest you do the same experiment, but without the vapor barrier material? Tape up that same insulation material on one side and add the ice/water and show what happens.
Yes I will do that to prove that it is only the barrier that is working 👍🏼
I'd also like to see how just a vapour barrier (with a couple of millimetres of foam backing or the 'bubble wrap' type) without any additional insulation performs.
In a small volume, such as a van, I'm wondering whether a thick layer of insulation is particularly pragmatic, considering that you need almost constant airflow. At night the duvet is your main source of insulation.
@@nagualdesign I do another with just reflectix to see if it’s enough to stop condensation forming. 🤔
@@GregVirgoe it’s going to be like an episode of Tomorrows World, with all these experiments 🔬🤓
agree, would like to see how just a adhesive backed insulation works on its own, like dodomat superliner.
this test is proving insulation + vapour barrier.
We’re currently looking for a van to do our own van build & your videos will be a constant help throughout our build. Thanks for sharing 👍🏼
Best wishes hope everything goes well for you both 😃👍🏼
I would like to see the same experiment with a small hole in the vapour barrier hat has been unsealed caused in a practical case through passing a cable though the vapour barrier and failing to seal it.
Hi Greg
I’m just about to start a van motorhome conversion and have just watched your video on vapour barriers!
I’m totally on your side.
If you get a chance please look on RUclips at a Vanology Conversion video on Not to have Vapour a barrier!!! 16 January 2024 They even leave gaps in the insulation to let the air in?
Let us know what you think??
I'm wondering, what is your view on the topic of penetrations in the vapor barrier, for example, where LED, sockets, etc. pass through it? Surely, these types of "penetrations" cannot be fully isolated by a vapor barrier and thus vapor will get through them.
Hey Greg, your video saved me IMMEASURABLE time researching this topic. Thank you for giving me hours and hours of my life back! One question that maybe you know the answer to: what impact (if any) do side and rear windows have on insulating a van?
Is it better to build out a van with no windows from an insulation & vapor barrier perspective, or does it not matter much? I'd expect having thin panes of glass around the van would diminish the effectiveness of the insulation and vapor barriers, but I hope this wouldn't completely nullify the insulation.
When you cut windows in those areas have a greater heat loss as they are no thermally efficient like insulation but it doesn’t affect the installed insulation or vapour barrier. Double glassed campervan style windows are thermally better.
With single glass you may get a little condensation on the glass but keep the van warm and well ventilated and that will be a minimum. Best wishes.
That is amazing, and you have certainly , proofed your point.
I have a big issue on a work van , with moisture collecting on the inside roof , and this is because I am running an engine to generate PSI, constantly during the day , in order to do my job. Which will always be done with side and back doors open. I would be grateful if you would list the materials you used.
There is a details playlist for the build of my van showing each stage.
I used PIR insulation slab for the floor and roof and side panels and I recommend Diall recycled plastic loft insulation for all the awkward areas and stuffing in beams. Seal over everything with double foil bubble wrap as a vapour barrier 👍🏼😃
Thanks for taking the time to reply.👍
Great experiment I always wanted to know if this theory works, and you proved that it does work " vapor barriers do work when done correctly"
Thank You for proving this theory 👍🇺🇸
Yes they do work and it why everywhere in industry when you have cold metal surfaces they are insulated and vapour barrier applied to prevent condensation. It’s not hard to do either.
Hello Greg your comments are turned off in your last video I don’t know if you new that. Ame in a van gave you a really good plug last night :). She converted a transit using your good videos 👍
Yes the video is made for children so comments are not allowed 😊
Those kind of proof videos are absolutely brilliant
It’s not just someone’s opinion you can see the facts for yourself 👍🏼
Perfect use of the studio..
I did watch an American video discussing that in dry areas, a vapour barrier is not required..
Providing your climate does not fall below the dew point even at night you do not need one correct. Doesn’t it get very cold in desert areas at night?
@@GregVirgoe I was just highlighting that one might not need it depending on location. I’m convinced European conversions should have one
@@theageingexplorer9488 and I was agreeing with you 👍🏼😃
I am 100% with you on the importance of the vapour barrier but I was a little perplexed to see you use those stick on steel spike things in your previous roof insulation video for holding the Celotex boards up, because what you've done there is introduce a thermal bridge into your nice efficient insulation. I'd be interested to see you do this experiment above with one of those spikes installed in the middle of your insulation, and see if you get a little spot of condensation around that tophat that sits on the outside of the insulation and the end of the spike. Van's are full of thermal bridges, it would be hard to get rid of all of them, but introducing more seems unnecessary.
Best video on RUclips on this vital subject....Fabulous
Thank you mark 👍🏼😃
You need to repeat the experiment with just the insulation and no vapour barrier now Greg. It brings balance to the test then. 👍🏼. By the way I’m a believer in vapour barrier 👌🏽
Agree. Another test is needed
Yes I agree with you. I will also discuss properties of different insulation as some already are a vapour barrier in themselves. Thank you 🙏🏼
What about all the glass windows in the bus , how they also get condensation on them, what do you do with that,?
You reduce the issue by providing heat and ventilation to lower the relative humidity and keep the temp above dew point
The reason I ask
Is I’m just about to insulate and I have a load of loft mineral wool and I will be using the same vapour barrier over the top.
Thanks
That would be fine. Just spend a little time and make sure to seal your vapour barrier.
Great experiment. Couldn't remember if I put the reflective barrier or insulation on first - knew I could rely on GregV to provide the correct answer! cheers :D
You are welcome Elaine, best wishes with your conversion.
Thank you Greg for this example, but what happens to the van in a heatwave, can this vapor barrier prevent the van becoming an “oven”?
Nice work Greg. Good, clear, simple way to get the facts across...Brilliant!
Thank you very much
Thanks, Greg - another great demonstration!
Moisture is not your friend. Proper insulation and a sound vapour barrier are as important as a proper ventilation concept to keep the ambient moisture at acceptable levels. This also goes hand in hand with CO2 management to maintain good air quality in your van. Mandatory info for all van builders!
Absolutely most important indeed 👍🏼😃
I believe a vapour barrier is vital for a van build in the UK or any cold climates. Even if you make mistakes and leave a few small gaps/holes I believe although condensation will occur it will be far less of a problem compared to no vapour barrier at all.
Absolutely correct and spot on 👍🏼😃
You're preaching to the converted here, but I really hope this provides support to those who still doubt the benefits of a vapour barrier. Great to see you at Camp Quirky, I'll be sporting your famous 'Half Hour' t-shirt very soon... 🙂
Thank you for your support Dan. Very much appreciated 👍🏼😃
When you peel the instulation I can see some small droplets in the bottom part of the can and also on the left side (few small dros). Is that normal? Thanks Greg, you are the superman of insulation!
It transferred from the outside of the foil tape that was stuck to the bucket when I ripped it open. It was not condensation inside there
Another great video Greg. I’m just starting out on our conversion, and taking your advice from your build videos. First one being, insulation and vapour barrier are essential. 👍
You will be doing the right thing well done 👍🏼😃
Have you covered in any of your videos the specifics of driving on the continent? Do you have a process for transitioning? What do you do about your headlight alignment?
There are stickers you can apply to your lights to cover part of the beam
@@GregVirgoe Excellent, I knew of them but wasn't sure how well they worked. Thanks!
Hi Greg. A good presentation but I have an issue with the way you did it. Your experiment shows the difference between having INSULATION + VAPOR BARRIER vs not having both. To show that vapor barrier works, you should have insulation on both sides and the vapor barrier only on one side and then see the difference. What do you think?
I will repeat it just with insulation and no vapour barrier.
Be interesting to see what would happen with just insulation and no vapour barrier. Maybe do the same experiment but hold the insulation on with chicken wire. Great video though Greg as all ways 👍
Closed cell foam like armacell might show some condensation when it's not entirely glued to the shell. There could be rust between shell and insulation.
But if it's glued on well, it's like a barrier by itself.
What happens when you need to drill through the vapour barrier , say to attach a cabinet to the wall?
In reality you don’t drill and leave holes when you fix stuff to the walls you use screws which are plugging their own penetration so there is no hole there. ☺️😎
@@GregVirgoe ok! I'll have to research more :-) I've done a super basic van conversion, but I've not done it right, going to have to take it apart.
I've been trying to get this question answered for ages!!! Thank you!
Im so happy to have answers for you 😃
The Legend Of Virgoe continues. Thanx for clever chemistry lab demo.
Thank you very much Edd 😃
Hi Greg. I’m a very tight budget and I’m thinking rather than spending €200 on silver bubble wrap could I use something as simple as PVC bin bags. Thank you for your very informative videos and looking forward to more. Regards Noel
Something stronger like this sheet would work ok and only £25 👍🏼
amzn.to/3SPda2L
Greg what happens with the vapour barrier when you screw board's too the battens what harm is done to the vapour barrier kind regards Jim
Nothing your screws are still in there, the barrier is still intact and there are no holes.
let's say I have been collecting van building video tips for a year or two now and this particular video popped back up inside my mind after seeing somebody apply spray foam to an interior (it looks good) - i recalled "oh but don't forget the vapor barrier") :)
Spray foam is a closed cell product so it is its own vapour barrier and would not need further treatment
@@GregVirgoe thanks! Yes, a few days later and I've understood that now
Am I right in thinking that closed cell foam doesnt need an additional vapour barrier on top because itself it is non permeable? As long as the layer is thick enough and the joints are foil taped? Thanks!
Thanks Greg we have followed your advice and seeing your experiment we are really glad we did. Especially when we go to Scotland in winter!
You can sleep soundly knowing you did a great job 👏🥰
Great video Gregg👍, I spent over £500 on the insulation and vapour barrier, I'd never put in a single glazed window for that reason also.
The double glazed ones are much better thermally. We do get some condensation on our bonded windows when it’s really cold 🥶
@@GregVirgoe A great excuse to leave the cold winters behind 😁👍
Good job. I've seen many videos of people building their camper vans with no vapour barrier and that made me sad. Mold is toxic, rust is a pain in the ass.
Exactly, why would you allow it to happen on a daily basis when it’s so easy to prevent altogether 🤔
@@GregVirgoe Lack of knowledge I guess
Hi,
I am worried about water moisture is in the van panels getting locked in and not circulating out . I have a crafter and they are known to leak from the outside trims . What’s you view on this Greg
Thanks for that, Good practical demonstration… as you say, attention to detail in the taping is all it takes
Yes exactly and it’s not difficult to do just a little time.
Question. Is it possible to know if moisture has collected inside a moisture barrier? Eg via a conductivity meter, or by adding a sensor inside the barrier, or something else.
Just spend a bit of time making sure you seal everything then sleep well at night and don’t worry about it 😃👍🏼
@@GregVirgoe unfortunately we're can't all be as perfect, and it's sure to give me nightmares leading to permanent mental trauma, and it'll all be your fault Greg ;)
I've just insulated my van with Dodo mat liner then the plastic bottle white insulation in a roll then another thinner liner from dodo Matt on top then sealed all edges and joins with that silver insulation tape, have I put in a vapour barrier ?
Great video! Thank you for sharing!
I'm curious what you or others think about "professional" spray foam insulation. Seems that would seal things pretty tight. Pros? Cons? Thanks!
Yes it’s an excellent insulator and will solve all condensation issues. Only cons are can be messy install and cleanup plus it’s a permanent solution and easily removed if needed.
You are an absolute genius 🤓. Your videos are all amazing 🤩.
I am trying to watch all of them , before I buy my next van for a conversion. Thank you so much for all the efforts and all the valuable information that you introduce into your amazing videos. Honestly, I would trust no one to do the conversion of my next van , but you my friend. Great job 👌👍 I hope you can do it for me 😉
I can help give you the right information. I don’t convert vehicles myself for a living. 😊
That was a excellent experiment Greg..............definitely worth spending time getting you insulation right on your van first...........stay safe.........thanks for sharing
Absolutely. Thank you for your support. 👍🏼😃
That was well different Greg and I was impressed with the result.
It really does work very well 👌🏼
Nice one Greg, nice to know all my hard work was worth doing. 😇😍
Love it when you do this stuff Greg, will wait for a moment of peace over the weekend to watch 🙂
Thank you and hope you enjoy it 😊
I'm 100% convinced now! Nice One Greg!
I’m glad it has helped you 👍🏼😃
Do you insulate doors as I've recently seen a video showing why it's a bad idea insulating doors as doors normally have windows and obviously handle where water can enter inside the panel to solve this issue the doors have drain holes in them so if you insulated you would have a problem
No insulation in the doors as you say the opening windows allow water down inside the doors plus so many mechanisms in the it would be impossible to do it without jamming up the doors.
Great demonstration. If air is an affective insulator itself wouldn't it make sense to just install a vapor barrier over the panels of the van leaving a gap of air in between your barrier and wall?
No the insulation value of air is very low and a cavity doesn’t vary with thickness either. Insulation no matter what form is always going to be better than just air. 👍🏼😊
For example the R value of air gap is 0.17 and 50mm of PIR is 2.3 so 14 times better than air alone. 👍🏼
@@GregVirgoe ahh thats makes much more sense. I guess i over estimated the properties of air! Thank you for such in depth educational van videos, it is greatly appreciated
@@v1ncepupp1o7 no problem 😉 always happy to help 👍🏼
Does it have to be "perfect seal", or will just adding some degree of barrier already help?
It’s not difficult to seal all the joints, edges and tape around services just a little extra time but worth doing.
Thanks Gregg. A Great demonstration. Do you have a plan for further practical demonstrations like using Insulation only without the vapour barrier ? This is a common alternate I hear about.
Thanks again.
Yes I will do a follow up video to this as lots have asked for that 😊
On my van I’m thinking of using the recycled plastic wool then covering over with a thermal liner, how would I go about fixing the ply wood layer on to the thermal liner? Would screw holes then cause condensation potentially?
I have learnt so much from this video and your others. Saw you at Stratford upon Avon doing a talk to the punters. Learnt much there as well. Cheers Greg.😊
Thank you for sharing, that's a great experiment. I have a question in regards to living in Australia. The majority of the places I go to are warm to hot/dry/humid heat. Is it the same deal for those conditions, is there an experiment that can be done to test that out? I look forward to hearing what is the better option for hot conditions, thanks in advance.
This is why I did my van as you did yours, thanks for the explanation though 😎💪🏼
I’m pleased you did the right thing 👍🏼😃
Great demo Greg, I'm currently doing a van conversion on a Citroen Relay and I have been diligently applying a vapour barrier, the issue I have is that I need access to the nuts that hold the rear light clusters in place, has anyone managed to seal off this area but still leave access for changing light bulbs?
It’s better to seal over and if you had to get access cut a hatch then tape back up after working.
@@GregVirgoe Thanks Greg sounds like the best solution.
Hi Greg , I have just insulated and about to move on. I'm flummoxed at the minute whether to put vapour barrier then framing , or framing behind the vapour barrier ? And should the electrics go infront or behind the vapour barrier ? Lucy
Hi Lucy. It’s best to put your vapour barrier over you insulation and your van then framing and cladding on top. If you have space in the depth of the framing you can put wires there but be careful not to screw into them. Or you can put wires in conduits in the van walls. Make sure to seal around any holes for wires with foil tape. Hope that helps 👍🏼😊
Such a great video! I’m in the middle of a build and the thought of moisture stopped me In my tracks. Glad to have found you on RUclips! Side note: Have you or anyone dealt with water build up in the rocker panels? I have run into this issue with Ram promaster 2500. I’m lost with how water keeps getting in. 🤷♂️ ty for all your effort in each vid!!
I’m aware that there is a poor design on the scuttle below the windscreen that allows water to pour onto the engine bay.
Make sure any drain holes are not blocked with debris, any rubber bonnet seals are intact. Use a bit of DW40 on head as water repellent. I have known others to cover the engine bay with on combustible plastic sheet to keep water away. Hope some of those help you 👍🏼
Fantastic video Greg! Would really appreciate your thoughts on the following if I may.
It is fairly easy to continuously seal the cargo area.
However, in my Renault Trafic, the A, B & C pillars are all connected across the top due to how they create the bodywork. So a void across the top, which all pillar voids merge into. It's easy to seal up the C pillar behind the sliding doors. The B pillar though, well thats got the seat belt mechanism inside so no way to seal where the belt is at shoulder height and the reel at the bottom has to come up the pillar. A pillar has an opening under the dash corner. So two questions here :-).
1: Stuffing the pillar voids with insulation as best as is possible? (getting it in there effectively still eludes me, i've thought about blowing little wads in with an airline...)
2: Vapour barrier it as much as is possible? even though there has to be an opening for the seat belts?
EDIT: More thoughts from me!
Given the pillars are subject to thermal conductivity from the outside skin, then stuffing them with insulation will have negligible effect right? It will stifle airlfow I guess, but not vapor over time?
Then given I cannot for a 100% barrier on the B pillar because of the seatbelt, surely the B pillar is still in its original situation, vapor in, condensation will form on the outerskin in the right consitions, dripping down into the sill? & that pillar is connected to the C pillar via the horizontal cavity across the roof line.
There nothing you can do with the seatbelt pillars or a lot of the cab floor or doors. You can close up the top beam section with some closed cell foam to seal it from the rest of the van. Minimising the potential for water to build up 👍🏼😃
Super series on building a camper van Greg! Really enjoy it. About to start isolating my Ducato with PIR isolation and Armaflex. The question I still have is when we use PIR isolation on the walls and the roof/floor there will always be an air gap between the steel and the isolation in opposite where Armaflex will leave no air gaps. Will there be condensation between the isolation and the steel? On one hand I think no, because the temperature on both sides of the steel is approx equally. Am I right? We will make mistakes on our first van build but would prevent one with isolation. Looking forward to your response.
Thanks a lot for Sharing...lgmario
Is it important to sie the Alufolie or can it uses Wood?
Awesome way to demonstrate the benefits of vapour barriers...
Excellent demonstration Greg. There's a tough crowd here in the comments, but the physics don't lie. They have two choices, use a vapor barrier or use a dew point meter and always keep the ambient temperature above dew point lol.;)
You would have to heat up the steel body of the van to above the dew point to stop it condensing. That’s a lot of heat to use in cold months.
If the insulation is permeable and allows moisture through to the metal then that alone won’t work.
Liked the video. How have you managed to insulate inside door frames ,hard ro access areas etc
Doors with handles and locks you need to put your insulation in plastic bags as the door still needs to drain from water ingress.
Door frames can be packed with wool from and holes, wrapped with thin insulation layer and carpeted.
@@GregVirgoe Thanks Greg.. I meant the likes of the top frame of the sprinter sliding door ( around window I fitted ) and the likes of the door pillars behind driver and passenger seats ,rear double door pillars plus top sections of rear doors. Thanks
Facts over fiction i’d say Greg. You’re akin to Ronseal … does exactly what it say in the tin👍 PS great to see you imparting your time serves skills at Camp Quirky this last weekend too 👍 Cheers
I’m happy to give my time and expertise for free so that everyone can benefit by doing the right thing and not be sidetracked by mis information and speculation.
Hi Greg - love your videos! Do you have a link to the vapour barrier featured. Thanks.
I would like to see test with air pockets in insulation, I dont think i can put insulation that tightly against wall.
It’s not how tight it is to the wall it’s just the foil barrier that’s doing the work here.
Thanks for this, Greg. We've done a vapour barrier, following your instructions mostly. I was wondering how worried we should be about small holes? We've screwed through it quite a lot, and I know if there are screws tight in that's not a problem. But what happens if you've accidentally made a tiny hole is your vapour barrier then dead?
No not at all, please don’t worry a very tiny hole will have vert little effect. Screws are plugging their own holes so you have done the right thing
You see it a lot in the US with young couples making and selling vans not installing a vapour barrier. It's less than a days work to fully line a van with a vapour barrier.
If you plan to only use it in very hot climates it’s not an issue but as you rightly say it’s so easy to do why not fit regardless and have peace of mind.
I´m about to insulate my box van soon. Can I use plastic wrap as a vapur barrier? Guess it would be cheaper?
A good quality plastic builders vapour barrier will work fine.
Some cheaper plastics are slightly porous 🧽👍🏼😊
@@GregVirgoe Ok Thanks, one more question... I´m using closed cell foam boards and filling the gaps with normal cheap urethane foam. Is it enough if I only use aluminium tape to those urethane gap parts or do I need to cover the whole walls with the vapour barrier plastic?
@@hungrycamperfilms as long as the foil tape sticks well to the closed cell foam. You may be better with closed cell tape. Like Armaflex sell.
Top advice from a well trusted source, Thanks Greg
I really appreciate your feedback 🙏🏼😊
wooden struts to frame the van before or after vapour barrier? thats what is doing my head in lol as vapour barrier makes it difficult to attach stuff to van
You can put your timber inside or outside the barrier it makes no difference. There will be no moisture so there is no problem. Also no problem fixing either as any screws are themselves a plug so there are no holes.
@@GregVirgoe thank you:)))