There is Moisture Trapped Inside my Vapour Barrier!

[@anonnanoo9586]

Should also be noted that, that calculation is based on a void with just air. A typical build will have an insulator of some sort in that void, reducing the air content much further and reducing the moisture even more so.

[@GregVirgoe]

Exactly 👍🏼 I also have a window cut in which is another m2 lost but so you could say this is absolutely worst case scenario. 😃

[@paulwitham8026]

Great video Greg extremely well explained, and in my opinion that's a finger up the nose of the doubters, thank you for all your helpful and informative information, happy travels to you and Lou 👍

[@peterdufton1067]

Another gem. Makes all the complicated stuff seem so simple. Thank you again Greg 👍🏻👍🏻👍🏻

[@1truthseeking8]

​@@GregVirgoeyou have failed...to account for "imperfect" /NON VACUUM SEALED vapor barrier...over time the barrier AND hit and cold metal will PULL IN vapor and TRAP IT...

[@douggraham5812]

@@1truthseeking8 Uh, no. Temperature differences do not "pull in" water vapor. And even if water vapor gets in between the van exterior walls and the interior vapor barrier, as you point out, the volume is not vacuum sealed. Air can migrate in, and it can just as easily migrate out. What can NOT migrate out is the water vapor in the interior of the van. Because there's a VAPOR BARRIER, you see. The only water vapor in the air inside the insulated wall is the vapor that can be held by the colder air, and therefore there is no condensation in there.

[@laryngis431]

This was one of the biggest headaches when I was doing my insulation - there was SO MUCH MISINFORMATION and those against it were vociferous. Your videos, plus some advice from a professional helped me make the right call. This video of yours is another in a long line that cuts through the bullshit with evidence and logical thinking. Thanks, Greg!

[@GregVirgoe]

Hopefully with this series I can help to point people in the right direction. Thank you for watching 😃👍🏼

[@bloochoob]

And that is why Greg is my No.1 go-to guy for van build info, he should be yours, too! Excellent work and advice that makes sense. 🥇

[@GregVirgoe]

That’s very kind of you and thank you for your support. 👍🏼😃

[@MC-dd8ls]

Glad I found this video. Your videos have been so helpful to me in planning my van build. Now that I've started my build I find your videos even more helpful because you provide so much theory to help me understand not only what I am doing but why I am doing it. I've said this toyou before and I cannot fail to thank you enough for the information you provide to us. I have learned sooooo much from you! A gazillion thank yous Greg!

[@GregVirgoe]

I try to give plenty of facts and science to show that the advice is good and can be relied upon. It’s not just me guessing what works. I’m pleased you found the channel and it’s great that it is helping you build an awesome van. Cheers 😊

[@tomthumb3085]

Well explained Greg. Perhaps people will now appreciate how much more efficient a vapour barrier is. You would undoubtedly create more trapped moisture without this barrier. Great video, thanks for sharing

[@GregVirgoe]

Without the barrier you are allowing moist air to continually get through your insulation to where it can cause condensation on the metal of the van. Thank you 🙏🏼

[@mmwaashumslowww7167]

Simply brilliant analysis using maths and science. If it's vanlife and there's a doubt, ask Greg as he's been there and has got T shirts 👕

[@GregVirgoe]

It’ll only take half an hour 😂👍🏼

[@tomthumb3085]

I agree. Greg is the “go to” guy for anything related to camper vans. His wealth of knowledge is, to my mind, unsurpassed.

[@helenarusso]

Hello Uncle Time how are you doing, nice to meet you here.

[@xgouldiex]

Iv never understood why people struggle so much with insulation and barriers. I'm a builder and all I done was apply the same rules for insulating and sealing my van as used on houses. Tried and tested methods and yes they use vapour barrier in houses the silver foil on the insulation commonly used is the vapour barrier and we tape all the seams

[@GregVirgoe]

The application for houses and vans are slightly different. Generally house building materials are porous and vapour barriers are used to prevent moisture ingress from outside to inside. In a van we are preventing moisture inside from contacting the cold metal skin. Glad to see you are in agreement to using them 👍🏼😊

[@thewanderingcaretaker]

Another great video. When I converted my van a few years back, I used rock wool with a reflective foil type vapor barrier. Not ideal, but it's what I had to hand and it does keep the van toasty. I recently decided to fit an extra roof vent, so had to take down some of the paneling and vapor barrier, and found that the insulation was bone dry, and considering rock wool holds water like a sponge, I think that proves residual moisture behind the vapor barrier is nothing to worry about.

[@GregVirgoe]

Thank you for posting that confirmation. We have rockwool in our van but with a good vapour barrier there will be no condensation in the first place. 👍🏼🤩

[@allanblackwell8655]

Great video Greg, a vapour barrier preventing vapour penetration. Putting a spanner in the works , let's not the sill drainage , don't know if they have a good or bad effect on moisture in the lower pannels, probably not.

[@GregVirgoe]

You do need to seal up any trim clips and holes to make an effective Vapour barrier. If nothing can get in there then there will never be any condensation or any need to drain the void. Those holes are only there because van manufacturers know their trim leaks like a sieve 😂😊

[@clearprop]

Great stuff, Greg. You are doing a superb job of calmly getting the correct information out there. It might have been a good idea to tag on the end of that video the amount of water that would have been held in that same void, based purely on condensation, by multiplying up the surface area of that uninsulated ice bucket!

[@GregVirgoe]

Yes as well as that it would continue to produce water as long as the steel is cold enough. 🥴

[@clearprop]

@@GregVirgoe I'll take the 5ml, thanks. 😉😁

[@hoggythreezero]

Hi Greg , Cheers for another informative video 👍 , nearly finished our mammoth 12 month sprinter build , 32 yrs experience under my belt ( & braces ) & much head scratching & changes of plan along the way , but certainly been a big help being able refer to your links for materials & watching your methods . Cheers Mike

[@GregVirgoe]

I’m really glad that the channel has helped you and hope you have many happy travels 🤩

[@carloknuwer1026]

Love seeing you break down every comment you got with the best science available. Top work, greetings from the Netherlands

[@GregVirgoe]

There are a lot of speculation and theories but very little proof so I’m here to back up my advice with evidence. 🤩👍🏼

[@kirklacut]

Thanks Greg, another excellent, very clear factual video. Your channel is an outstanding resource for the diy van converter!

[@GregVirgoe]

Thank you very much 👍🏼

[@richies6898]

Excellent information Greg, this whole insulation debate does become tiring with some of the arguments people put forward. Years ago, my first van was an old VW Westfalia which had been insulated from new without any barrier, I had to replace a lower wing panel and sills as the lack of barrier had allowed moisture into the insulation with all the subsequent problems you would expect. I used a basic polythene barrier in that but never had a water collection issue afterwards. My current LWB VW Crafter collected so much moisture on the roof as an empty shell over the winter, i thought it would never stop, I put the 50mm PIR board on the roof back in January which eradicated moisture build up overnight, much like your bucket experiment demonstrated 😉. Practical experience has taught me those basics, but your maths and science should certainly put the doubters on the right path 😆

[@geoffcampbell7846]

Nice one Greg. Many people will want to know this I'm sure, and you have provided the information on how to confirm the results. Most folks wouldn't know how to get started to go though this logical process, so another Vergo gift to Vanlife. We'll done. 👏👏👋

[@GregVirgoe]

Really appreciate your support. Hopefully it will help to give people the right information 👍🏼😃

[@canaryseasider]

Great calculations Greg. Like you my van is fully insulated and vapour barrier’d and was done in march/April time. Hope to see you this weekend at Stratford.👍🏻

[@GregVirgoe]

Glad to hear you did the right thing. 😃

[@helenarusso]

Hello Ken how are you doing, nice to meet you here.

[@4486xxdawson]

Its always those who do little research that say your doing it wrong , good for you showing your testing , to be hounest the out skin of a vehicle is never 100% air tight anyways so its going to change up and down with the weather regardless , some people just like to complain from thier couch , others get out there and live ....thanks for the videos 👍

[@yodocampers]

Hey greg ,thanks to be alive in my timeline. Ur a genius and a mentor far away. Have a good life Cheers!

[@GregVirgoe]

That’s very kind of you. Many thanks 🙏🏼

[@alanpepper7258]

Hi Greg. I understand a vapour barrier is used to stop any moisture created inside the warm van reaching the dew point of the cold outside. maybe not like that but hope you know what I mean. maybe with your knowledge you could make a video on this aspect. You certainly made it clear very little traped water is not an issue. Keep up the good work.

[@GregVirgoe]

Please take a look at my insulation workshop video. That does cover it I’m sure 😊

[@annickbonnier-roy9377]

Essentially you want to insulate when its cold as the ability of the air to hold water vapour is low with a lower RH (as much as it can be). Or if its hot you want to have a low RH. Awesome Video! nice to clear up a lot with facts.

[@GregVirgoe]

You are correct. Colder air has less moisture content even though the relative humidity may be higher. 👍🏼😊

[@richardedwards9389]

There's a reason why Greg's name keeps popping up on this subject over all the place - he knows what he's talking about!

[@GregVirgoe]

Thank you 🙏🏼

[@jazzz60]

Love the vid. This is the series of vids I’d recommend everyone I meet to watch. I did mine halfway between summer and winter and it’s good to know I didn’t trap that much moisture. Backed up of course by cutting into it after months/years and finding it still bone dry. If you hear anyone say “let it breathe” run far away. 🤣

[@GregVirgoe]

Thanks for this confirmation 👍🏼😊

[@craster_van_kippers]

Excellent video again Mr Virgoe. Absolutely agree that the vapour barrier is more to stop condensation created within the van. The amount “trapped” behind is indeed negligible. I have however pondered the idea of a strategically placed breathable membrane which would let trapped moisture out but not let it in. Basically thought of this while wearing my Goretex shell in the pissing rain. Wet outside no sweat inside.

[@GregVirgoe]

Don’t over complicate it just fit a good vapour barrier and sleep easy easy at night

[@hungrycamperfilms]

@@GregVirgoe But Greg, you didn't put a vapour barrier on your floor when you build it. I just yesterday watched the floor video and was wondering why there's no vapour barrier. Only aluminium tape and the foam boards and wooden studs? Confused. Cheers!

[@GregVirgoe]

@@hungrycamperfilms the PIR slab is foil faced so that is the vapour barrier. Then you only have to foil tape over the timber onto the foil of the boards to complete the barrier. Once I had finished taping the entire floor was one continuous foil finish. No need for anything more than that.

[@jm-um1tx]

Thanks for the very clear and accurate explanation. The question isn't whether the water is trapped in the insulation during construction, it's what happens if there's a leak and liquid water gets in. If the insulation is completely sealed inside a vapor barrier, won't the water collect either at a low point or condense against the cold metal rather than gradually evaporating or draining back out? Isn't most house insulation installed so it can equalize moisture content with the outside air to avoid this problem?

[@GregVirgoe]

I would not put water pipes in a sealed void where they cannot be accessed and potentially a leak can happen that’s just very poor design and you would be asking for trouble in a moving van. If you don’t fit a barrier you’ll have a lot more water to deal with than a leak

[@tonym2540]

If I understand right, the calculation given is for one wall. So, considering all other surfaces we might need to multiply by 3, giving 15mL. This is still a small amount of water, but if you want to reduce it further (or remove whatever water might be trapped back there for other reasons), you could cut a hole in your barrier, seal in a container of desiccant for a time, remove it and seal things up again. Weigh the container before and after to see how much water you removed.

[@GregVirgoe]

With all the insulation in there in reality the volume of air is actually very much less so probably talking about one or two drips worth 🤩👍🏼

[@tonym2540]

@@GregVirgoe Very good point. I also did a quick calculation and estimated that each mL of water can rust 2 grams of iron, again a small number. So, in summary I agree this is probably not a problem in your case. But in case someone thinks it is a problem, the desiccant idea is a way to check that, perhaps quantitatively.

[@helenarusso]

Hello Tony how are you doing, nice to meet you here.

[@slalomflex28]

I fitted a full vapour barrier because of your videos pal. Never had any problems. Cheers👌

[@GregVirgoe]

You can sleep easy with no stress 😎

[@ironwooddesigns9532]

Also, the FIRST warm day in the sun that heats up that wall will drive all that moisture out. The walls are ventilated at the very bottom and vapor pressure increases with temp.

[@russ1046]

This is exactly why I watched your van build ... actual, factual, verifiable information 😁

[@GregVirgoe]

Thank you 😊 not just random thoughts 💭👍🏼

[@kulfonbustardo1588]

greg your videos are so well done and easy to watch and learn from i have now been living 3 years full time in my stealthed self build campervan living a life of persueing my passions and sporting hobbys and alot of that is thanks to you ive said it before but thanks again. try not to let the negative comments get to you. i learnt today on a podcast (freakanomics) that we naturally absorb negativr feedback as much as 4 x more then positive feedback due to a hangover effect reguarding safety in the wild. (life has to win every day but death only has to win once) anyways top work as always and thanks again cheers matey

[@GregVirgoe]

The one good thing is I have total control here 😊 those that are rude simply get deleted and forgotten about. I don’t waste my time on negative people. 😃

[@projectt4587]

The only fella out there who can put common sense into a mathematical sum and the answer turn out to be exactly what common sense says. Great video Greg, I can’t do maths but I can work out that insulation makes the air content less in the void and therefore less water content. I thought a table spoon but I’m surprised to see it’s less than a tea spoon 👍

[@GregVirgoe]

Thank you 🙏🏼 I shall keep putting out the right information for those that want to do the right thing 🤩 Thank you for your support.

[@michaelthorn2229]

Top job Greg as always. Hopefully that will silence the keyboard warriors. I insulated my van the same as yours with the vapour barrier etc and it’s been perfect for 3 years. No damp at all in the living space and no wet areas between the van skin and vapour barrier. Its been perfect…👍

[@GregVirgoe]

There will always be a few that disagree but let them crack on with a soggy van 🚐🤣

[@marks-0-0]

Well explained Greg. I think it would also be worth adding that as a rule of thumb its not a good idea to insulate in cold damp conditions. Think sitting in your car when raining and seeing all the condensation on the glass.

[@GregVirgoe]

Obviously don’t insulate if the inside of your van is wet. However colder temperature do have less moisture content in the air.

[@bobmurdoch8505]

I have watched all your blogs and thanks for all the information. Just like to say you are a very clever man thank you 👍👍

[@GregVirgoe]

That’s very kind of you. Thank you 🙏🏼

[@littlepotato2741]

I remember arguing with someone on Reddit about vapor barrier. He made an offhand comment that only armchair people worry about vapor barriers. At the moment, I live in a humid environment and a vapor barrier is definitely part of the plan. After some frustrating discussion with him, I was finally able to get some information out of him. He used to install insulation on commercial refrigeration trucks and was trying to leverage that experience to call anyone using or recommending a vapor barrier, an idiot. After some more frustrating discussion, I was able to get him to admit that they used a closed cell foam for their insulation. I had to explain to this "knowledgeable professional" that closed cell foam is insulation AND a vapor barrier. That he used the very thing for years he was now deriding as something only used by idiots. At that point, he fully lost it and just started spamming insults at me. It's amazing how people will get stuck into one way of thinking, even when they should have the experience to know better.

[@GregVirgoe]

Yes there are a few insulation materials like closed cell foam that are a vapour barrier too and don’t need additional treatment. Also neoprene foam like Armaflex is a similar product. 👍🏼😊

[@ruinunes8251]

I don’t even have a van and I gave a thumbs up because of the explanation.

[@GregVirgoe]

Thank you for your support 👍🏼

[@kahernebally]

Brilliant, well done for setting the facts straight. Very informative videos of how to build your own camper .

[@GregVirgoe]

I’m glad you like them and thank you for the support 😃

[@gonefilming2020]

That's such an important video, as I always had the same concerns (about ambient humidity while insulating). It saved me the trip to the desert to insulate! 😎👍 Thanx Greg and cheers from Germany! 🚐☁🍀

[@rogerstarkey5390]

You have DESERTS in Germany!!!?? 😉

[@gonefilming2020]

@@rogerstarkey5390 Not yet. But we're working on it. 🤣

[@GregVirgoe]

Thank you I’m glad that has confirmed your thoughts 😃

[@bertoltb13]

Great video. If/when I build my own van I will take this great information in. I used to have a 80s VW brick and the condensation was terrible. Good to know the science. 30 yo Hymer so far so good.

[@GregVirgoe]

I’m really pleased it has helped you make the right decision.

[@onemanandhisdog9]

Right, that's it, I will only use a vanbuilder that builds in a vacuum!! 😂😂

[@GregVirgoe]

🤣🤣

[@AlanHossack-j9r]

Hi Greg, I think your videos are very good. It should be noted however that the void between the outside skin of the van and your vapour barrier should not be air tight. There are drain points all along the side of the van to drain any moisture collected.

[@GregVirgoe]

I have sealed all the possible holes in the body work to create a sealed void.

[@deranocasper]

Greg your class to take the time out and do some home work for us on moisture and Insulation and vapour barrier your videos are first class you take pride in your work 5mls medicine spoon 🤣🤣nothing that class hope your getting a well deserved rest over Easter I watched your video on the new van conversion side windows being fitted attention to detail first class every time will the van be suitable for 2 adults and one child? 😊

[@GregVirgoe]

Thank you very much. Most of that knowledge comes from studying the subject at university for 4yrs. I pleased you appreciate the videos. Think the new van may be too small as we plan to swap seats out for just two singles. 🚐😊

[@chrisneville7310]

Excellent video Greg and very informative. A vapour barrier is essential . I've hit -4 last winter, diesel heater on and not a drop of condensation inside the van. I've used moisture resistant MDF for the walls,. Barn doors side and back, fully insulated. Buffalo board for the bed base. We build houses in every weather scenario. If it's done right it's done good. 👍

[@GregVirgoe]

That’s excellent news. Glad to hear that it’s working for you too 👍🏼😃

[@mbrider56]

Nicely explained Greg.Clear and simple instructions that explain everything. job done. (Nice to see Alex from "Mispronounced Adventures" in the background....)😄

[@GregVirgoe]

I’m glad you liked it 👍🏼😃

[@peterblackwell6748]

Another brilliant video Greg highly informative 👍👍

[@GregVirgoe]

Thank you very much 👍🏼

[@jeffsteinmetz7188]

Thanks again for the great content! I don’t claim to be an expert, but I still have questions. If I lived in the UK I would defiantly do as you recommend. However, I reside in the south western USA and we have a hot and dry climate here. I do agree with you one should take measures to ensure the moisture does not get into the walls, but what about providing a way for moisture to get out and using materials that release the moisture (natural wool)? Lots of people in the USA are using Havelock Wool because it is mold resistant and releases moisture unlike many manufactured products. A trip to the desert for a few days and one could dry things out. Please understand l am not challenging your expertise, I am trying to learn and better understand. Thank you!

[@GregVirgoe]

If you live in a hot dry climate you would not need to worry about condensation. Havelock wool will not stop condensation forming on the van walls if it’s cold outside. To promote it as anti mould is ridiculous. What they are saying is it’s ok for you van to be soaking wet. Why would anyone in their right mind want that to happen at any time?

[@rudivandoornegat2371]

And that was another episode of the UK Mythbusters, van life edition. Well done, Greg!

[@GregVirgoe]

🤣 thank you 🙏🏼

[@charliecenta]

Random... the van outside the window is the guy from Mispronounced Adventures, another amazing KZbin channel for van builds! Do you guys just all hang out together now? 😁

[@GregVirgoe]

I was filming this at Stratford International Campervan show and we both have our vans on display 😊

[@Chequr_Prostate]

Are you assuming that you have created air tight void behind your vapour barrier? Wouldn’t air be drawn in through the gaps from the outside? I wonder if you could also see vapour being transferred from the inside of the van and condensing on the inner skin of the vapour barrier, that maybe more of a problem? I think it’s fair to assume you can not eliminate every drop of water, we just want to keep it to a minimum. Great video and as helpful as ever.

[@GregVirgoe]

It goes without saying that you need to seal things like trim clips etc but that’s not hard to do. Spend a little time doing a good job and you’ll have no worries.

[@888johnmac]

once again .. destroying Keyboard Warriors with science & decades of practical experience .. as always , thanks for sharing knowledge & experience

[@GregVirgoe]

Really appreciate your support 👍🏼😃

[@Scrambler85]

Great explanation. When I was planning my van build this was argued on every channel and van build. I watched years of van builds especially this channel. I live in South Carolina in the USA where we have a simi tropical climate with high humidity year around. What I did was no vapor barrier. I installed 1,200 watts of solar panels with 900 amp hours of lithium batteries and a mini split AC/heat pump. And a Propex HS2000 propane heater. I can control the climate and humidity year around no matter where I take the van. Definitely a thumbs up for the video 👍

[@GregVirgoe]

You are fortunate to live in an area where it hardly ever drops below dew point. Also AC is the perfect dehumidifier and will dry out the inside air too.

[@paulwatton2415]

Hi Greg nice one makes sense to me , no matter what u say someone will disagree but I know u would not put yr word on it if u where not sure of yr facts , thanks for sharing and if I ever get to build a van I’ll take your tips as sound advice cheers

[@GregVirgoe]

Thank you for your support. 👍🏼

[@nglyo]

Excellent video, I love these technical vids you make! Thank you!

[@GregVirgoe]

Glad you liked it 👍🏼😊

[@buddysinsight9834]

I am going to build a van next summer and your videos are superb Greg. I would love to know the ambient moisture content inside the living area after two people have slept in the van. I use a dehumidifier in my 6m x 7m bedroom at home and after 1 week it’s pulling out 2 litres of water from the soft furnishings bedding etc. It shocks me really. I can’t explain how nice it is when you feel the crisp dry bedding you sleep all night. I only mention this because moisture emits spores that’s really bad for your health. A van is a confined space and condensation builds on areas that can’t be insulated like glass etc. Is it healthy to live in a van long term I wonder. Roof vents and circulation of air is very important I should think. I want to buy a really good young van with a bit of crash damage so I can create something special from the ground up. I build houses so I have the full skills to create something I love. 👍

[@GregVirgoe]

Yes and all tha moisture inside your van would condensate on the van walls if you didn’t fit a proper vapour barrier.

[@wagonwitch]

Do you think putting a vapour barrier in a new build on an old van is worth it? I’ve got a 1874 Vw. I’m doing all the work myself with gratitude for you generous sharing of information.

[@GregVirgoe]

Yes definitely worth it. Just make sure to seal up any trim clips or holes etc in the bodywork.

[@Ellie_Melloy]

It seems you calculated for the void being empty, just air. If the van is insulated properly then the air volume will be massively reduced, and your 5.2ml will be more like 1ml. Now I need to think about sealing any drain holes outside. Every time I see one of your videos my to do list gets longer :P

[@GregVirgoe]

Yes that’s right but even so the result is nothing to worry about

[@sieni]

Thanks for another interesting video! I started my van build in the winter at -5 celsius. As I was inside the van, a lot of condensation formed on the walls presumably resulting from my body heat and breathing (I also had a small heater in the van). The walls were so wet I decided to postpone the insulation for the summer. When I checked the van the next day, the moisture was still there but had obviously frozen. I think not only should the environmental moisture be taken into account, but also moisture resulting from the person building the van. Adequate ventilation should help of course.

[@GregVirgoe]

Obviously don’t insulate if the walls are soaking wet with condensation. Use lots of ventilation by opening doors to get rid of that moisture. If the inside conditions match the outside there will be no condensation.

[@Namdor2012]

Use a good electric radiant heat, not a gas if your working in a van as gas has a high moisture content..Open the roof vent or windows a bit if you don't have a vent, crank the heater up and all moisture in van will head for the clouds..lol..

[@Scamdemic]

Hi mate @Greg Virgoe. Been binge watching your superb videos from way back (Looking to buy my first van to convert) and this more recent video caught my eye. I've been trying to learn as much as I can, and I was wondering about the possibility of painting all the steel internals with some sort of rubberised paint? So in essence creating a fully sealed rubber skin on the whole inside. Is that even a thing? Thoughts? Recommendations? If it is 'A thing', would it be a good idea before applying more typical insulation etc over that surface? Many thanks for all the videos, I've been watching and subscribing to quite a few channels, and I'm really enjoying yours.

[@GregVirgoe]

Hello Neil. I wouldn’t waste your time as money doing that. A thin layer of any material wouldn’t be enough to raise the surface temperature above dew point and you would still get condensation issues. Just go with my methods and you’ll not have any problems

[@Scamdemic]

@@GregVirgoe Brilliant, cheers mate. Appreciate the speedy response! On the hunt for a Vw crafter or Merc Sprinter and will definitely be taking a lot of your advice.

[@ian_morg]

That’ll learn em 😂😂 Great to meet you at the ICS, it’s been a great weekend😍😎👍🏻

[@GregVirgoe]

Good to meet you too Ian 😃 shame the weather hasn’t held out. Best wishes 👍🏼

[@ian_morg]

@@GregVirgoe supposed to be ok from 10 apparently 🙏🏻 we’ve got an air awning to put away so fingers crossed 😂😂

[@rallycorsa1600]

It's actually much less as probably 90% of that void is taken up with your insulation materials. Looks like you filmed this at Vanlove Fest, a good day out I thought👍👍

[@GregVirgoe]

It was filmed at Stratford International Campervan show

[@davidmcdaid8446]

Hi Greg Not sure if you’ve covered it before, but I have a question about anti-condensation coatings.‘ I rent a shipping container that I use for storage and as a workshop. The ceiling and upper parts of the sides are treated with a coating to prevent condensation - which it does very well. They describe it as graphite, and it has an artex like finish. Is that something that might work either to supplement or replace a vapour barrier? Thanks in advance David

[@GregVirgoe]

To prevent condensation the surface temp must be above the dew point so the layer must have some insulating properties to achieve that. Do you have any links to the product? Cheers 😊👍🏼

[@Steven-e7c]

Thanks for this useful information! 👍

[@GregVirgoe]

You are welcome 🙏🏼

[@RedBatteryHead]

Science to the rescue, again! Great Gregg!

[@GregVirgoe]

Cheers Jefff 🍺

[@brianmcclure8012]

Super informative Professor Greg!!

[@GregVirgoe]

Glad you liked it 👍🏼😊

[@sparkygazza]

Greg your a van build Legend mate the best videos by far.👊💥👍

[@GregVirgoe]

Thank you very much, really appreciated

[@sparkygazza]

@@GregVirgoe no probs Greg its good of you to pass on your knowledge.

[@41aidata]

You Are the King of van .. Cheres from Denmark🍻

[@paulus47]

wonderful calculation Greg thank you

[@GregVirgoe]

Glad you liked it 👍🏼😃

[@PrisonersNoLongerAccepted]

I'm not even getting involved in the maths of this topic because I'll lose lol but as usual your approach is brilliant as always, massive thumbs up 👍

[@GregVirgoe]

Many thanks for the support 👍🏼

[@john-xx8nc]

Excellent vid , well put together and your bang on nothing to be concerned about cheers

[@GregVirgoe]

Thank you John 😃

[@johnthacker8315]

Well done Greg great information

[@GregVirgoe]

Thank you 🙏🏼

[@277kne]

Hi Greg, I've recently re watched you videos on your floor. Also have seen others use aluminum square tubing on the floor. I like that you sealed it. Was wondering about any condensation under the plywood floor. Guessing none because it isn't exposed to the air. One builder was using airflow,ventilation under the floor and behind the refrigerator cabinet. Could you explain it again but in different words? I would think wood or metal beams glued with and industrial strength, to the floor wouldn't need additional screws or bolts. In an accident any part can get snapped off. Once the cabinets are fastened to the wall, it holds down the floor. I'm re watching some of your build videos.

[@GregVirgoe]

There wouldn’t be any condensation on the plywood as it’s warmer at that point so it’s above dew point. Timber would be better than aluminium as it’s better insulator. Ali will conduct the cold. I would recommend a sikaflex 512 or 522 adhesive for the battens making sure the floor is clean of dirt or grease. Thank you for watching.

[@277kne]

@@GregVirgoe Than you for responding. I've seen too many videos and one guy is a builder in N.J. You may have see his videos. Humble Road. I think he used a flexible adhesive with aluminum. He keeps talking about heavy mass vinyl. I'm guessing the cold transfered through the metal floor and walls isn't a problem because of the insulation against it. Did I get that somewhat correct? I understand the the warm moist air as you have mentioned.

[@GregVirgoe]

@@277kne yes I know George he has a very good channel and does very good videos too.

[@riboid]

@@277kne His heavy mass vinyl will bring some insulation properties but primarily acoustic benefit and if he is screwing or applying anything on top of it, then it will act as a thermal/acoustic barrier.

[@missionmallory]

We spent 4 days with a heater and de - humidifier to lower the moisture content in the fibrous insulation. Wish I hadn’t bothered !

[@GregVirgoe]

Having the walls dry when you apply is all that matters 😃

[@kelsolokey]

I always forget this is even an issue for people, that's because I live in Utah, very dry year round.

[@GregVirgoe]

Lucky you 😊

[@stevewild4449]

Brilliant info. Greg, very informative 👍

[@GregVirgoe]

Thank you 😊

[@iceyblack4906]

Love this guy and his great insight

[@GregVirgoe]

That’s very nice 👍🏼 thank you 😊

[@williammercer6074]

Hi Greg once again a spot on video. But would the insulation behind the thermal barrier take up a lot of the volume due to its mass and make the water content even less especially celotex and the like which is very dry and sealed due to its manufacture process? If that is the is the case you may have to get an eye dropper out to demonstrate. LOL

[@GregVirgoe]

Yes exactly so in reality actually much less than I calculated 🤩

[@bobbyfischer6786]

Just came in to see if any flat-earthers had been in to try and contradict the laws of physics in the known universe. Will check back later. Good on you gregg.

[@jay-hv6mc]

Yep. Water seeks level and must be contained. Real science you can walk in your kitchen and prove. And yes good video greg thanks

[@GregVirgoe]

It would be a dull place if we all believed in the truth 😂🤔😃

[@choxiden3776]

Hi Greg. Great channel. Love your videos. A question. I am preparing for my own build if I can ever find a suitable van for my budget. Would it be worth using a dehumidifier in the van at the time of creating the vapour barrier? I know the amount of water is negligible from your explanation but perhaps the use of a dehumidifier might make it even lower? Thanks for reading. Have a good one!

[@GregVirgoe]

It wouldn’t hurt combined with some heating if it’s winter time 👍🏼

[@backbeatpat]

That's interesting. I come from a building background and we work with vapour barriers all the time. We believe that the spaces should be ventilated to allow moistures escape. In buildings where no ventilation has been provided it is not uncommon to find the insulation saturated at the very top of the wall or roof. For your small wall with the medical spoonful of moisture calculated for the volume of the whole wall - in reality this small moisture content will in all probability exist at the very top of the wall, maybe making the insulation in that area feel damp. If vents are provided then the moisture can thus escape thus protecting the space and the insulation. Might this be relevant in a van build?

[@GregVirgoe]

NO, not at all relevant. The metal skin of a van is a completely different application to material used for building houses. We are preventing condensation from forming on a cold metal surface. Building materials are porous which is why you need to deal with the moisture in there. Totally different applications.

[@backbeatpat]

@@GregVirgoe I agree most building materials are porus. In roofing situations where metal or some non porus material is used - to avoid condensation arising it is advisable to allow for ventilation of the space as it allows mositure escape. Might this be applicable to a van wall or roof?

[@bntambridge]

Hi Greg, what about the van cab? I didn't see you mention that in your videos. Some other van videos have insulated the front doors and cab roof.

[@GregVirgoe]

It’s important to insulate the van cab roof as that is prone to condensation. Van doors are not easy to do as they have opening windows and you can’t seal them from water ingress so they need to be constantly drained of water 💦

[@craigbaxter4842]

Yet another great informative video Greg👍 BTW is that young Alex's Transit behind you?

[@GregVirgoe]

Yes it is, we are at the international camper van show in Stratford 😃

[@MispronouncedAdventures]

Great spot! I didn’t even know I was in the video!!!

[@williamolsen8517]

Awesome. I love math and facts. Well done. I will be using a vapor barrier!

[@chimparse]

Great info, well explained 👍

[@GregVirgoe]

Thanks! 👍

[@Pelt101]

😁😁 Quality… that told em Greg. Well done mate.

[@HammyHunting]

Thanks for doing all the calculations Greg it would have been beyond my brain cell capabilities 😂👍🏻

[@michaels7127]

Great stuff brother keep it up!

[@GregVirgoe]

Thank you 🙏🏼

[@rajakhan354]

Great vid mate. everything backed by science. only place to go if you thinking of converting. thanks Greg

[@GregVirgoe]

Thank you for the great feedback 👍🏼

[@Alivefrom45]

Great video Greg.

[@GregVirgoe]

Thank you 😊

[@graham_ozzy]

Second video of you KZbin channel and I’m very impressed by your information given well done 👏 Ps 1 new subscriber 👍

[@GregVirgoe]

Thank you for your support and hope you find my other videos to be useful too 👍🏼😃

[@SamLamingWingsuit]

Hey there Greg, thanks for another fantastically informative video. The room I live in at the moment is 90/100% humidity in the early morning, but not really cold enough yet to need a heater on - I'm wondering with a good setup in a Van scenario what the numbers tend to be like in such conditions? Would be very interested to hear your thoughts. Thanks so much for all your content, all the very best to you.

[@kevgermany]

I added a barrier. But put so many holes in it it's close to useless. I'll worry some time. Maybe. I guess the only way to avoid the problem is to use spray foam like they do on narrowboats these days.

[@GregVirgoe]

What sort of holes? Screws don’t leave holes. Did you seal up around sockets etc?

[@kevgermany]

@@GregVirgoe yes, the screws. But let's see what happens. I need to use it, not spend more time chasing things.

[@Namdor2012]

@@kevgermany Screws seal, they won't hardly let any moisture vapour in, if any..You didn't build a submarine where there is pressure that forces water in...

[@kevgermany]

@@Namdor2012 hope so, fingers crossed

[@danielodonnell445]

Another great piece of advice tks.

[@GregVirgoe]

Thank you 😊

[@perrywelsh2558]

Thank you from Oz mate

[@GregVirgoe]

Thank you

[@ronbooth1382]

wow, well over my head!! I have more chance of teaching you MIDI then understanding that. Love to Lou

[@GregVirgoe]

I’m glad you watched it. 😃👍🏼

[@RAL2010]

a real engineer!

[@GregVirgoe]

Thank you very much

[@NomaddUK]

Hi Greg. Now that you have been living in your van for quite some time, is there anything you wish was different or wish you had added or not added? I am just about to start my next build and have sold my Renault Trafic to buy a Citroen Relay/Boxer/Ducato. Before I start it though I was hoping to get your insight as you have lived in yours for a while. Cheers pal. Hope all is well with you guys!

[@GregVirgoe]

Hello, yes I didn’t need all the 3pin sockets we installed and only use the inverter very rarely now. Try and power everything off 12v DC as much as possible. I ended up fitting more 12v usb sockets in the van.

[@peterburgess4637]

drains in the sills? hope no one seals these to stop dampness getting in.

[@GregVirgoe]

If the void is sealed nothing will get in there in the first place. That’s the whole point 😊

[@peterburgess4637]

@@GregVirgoe Hi Greg did you seal the drain holes? i watched all your vids..several times, but I can not recall any mention of these... I totally agree with you if it is sealed with a water proof barrier then nothing will get in, and happy days,

[@mikkip201]

Hey Greg, very informative and detailed video. However it didn't really address the main criticism I've seen toward vapour barriers - that is, unless there is a perfect seal with 0 perforations, moisture will collect between the vapour barrier and the interior wall of the van. My original reaction to this criticism was 'just make a 100%-proof seal', but since learning that even a minute gap, such as one made by a screw-hole, is enough to compromise the function of the vapour barrier, I've again returned to being undecided on whether a vapour barrier is essential or a trap. Those who advocate for skipping a vapour barrier will also say that moisture is able to dissipate without one. Whereas with a vapour barrier, even one that is 99.99% sealed, moisture will get in (through the 0.01% gap) and subsequently become trapped. I have no opinions myself - I just wanted to hear your thoughts on this take, considering it wasn't addressed in this video.

[@GregVirgoe]

Firstly there is not a hole when screws are fixed the screw is plugging it’s own hole very tightly. Secondly it is not difficult at all to make sure everything is sealed. You just need to spend a little time to do it. Not hard at all.

[@Namdor2012]

A few screw holes even a few small OPEN holes WILL NOT suck moisture in like a tap, a van is not a submarine where you get a massive vacuum effect ...No vapour barrier you have one gigantic enormous hole, and once moisture builds up in the insulation it does not retreat out easily, then look out...

[@gordonbrown1087]

Hi Greg great vlogs thinking of doing a self build but first going into Europe in our motorhome my question is do you fill up with food eg breakfast stuff or do you bu

[@gordonbrown1087]

Sorry do you buy as you go along thanks Gordon

[@GregVirgoe]

@@gordonbrown1087 we take essentials like tea, coffee and things like marmite as English varieties are expensive to get abroad. But generally the main supermarkets and hyper market are fantastic for fresh produce so we do our main food shop abroad. You can normally find Lidl in most places too 😃

[@gertiesgoals7582]

@@GregVirgoe thanks leaving Sunday for bulgaria never done a trip in europe excited but nervous

[@GregVirgoe]

@@gertiesgoals7582 it’s so much easier over here and so many free services and parks ups

[@greenfrog58]

Great video! Even better Numbers if you substract isolation material… 😜

[@GregVirgoe]

Yes exactly 🤩

[@johnwren3976]

Is that void actually "sealed"? 🤷‍♂️ Most walls have drip holes at the bottom seam open to the environment.