IS A VAPOR BARRIER NECESSARY? Vintage Camper Insulation Questions

[@ProjectNineOaks]

Perfect timing on this video. I'm getting ready to putting insulation on my camper build in the coming weeks. I like your rigid foam idea. Thank you and keep it up!

[@TrailerTrashtoTreasure]

Thanks! I will fully admit I don't know everything about insulation, but I think I'm making sound decisions.

[@thisoldbelair]

It’s so fun watching this trailer come together. Nice work, looks amazing

[@TrailerTrashtoTreasure]

Thanks for watching! I'm really happy with how it's all working out, but I have to admit I'm getting close to the next phase of the rebuild, and I'm a little bit nervous for how it's going to progress!

[@zanesutherland406]

Curious other people’s thoughts, but I think what you’re doing is just fine. I think if the camper is sealed up well from the exterior and you are monitoring and controlling the moisture levels inside then hopefully condensation and moisture in your walls won’t be an issue. I’ve lived in my camper full time since September 2018. Mine is a 1988 Terry Resort 24ft with aluminum siding, wood framing, fiberglass insulation. I repaired any water damage and sealed it up really good. I have a humidity monitor inside and I make sure to keep in below 50% or there is a chance for mold to grow. Usually it stays between 25-34% humidity. I make sure to exhaust any steam, cover any boiling water. Keep the temperature constant in the winter so there isn’t extreme temperature fluctuations. I’ve got silica packets in all my cupboards, a couple bamboo charcoal humidity absorbers, like 6 small moisture absorber tubs you can get at the dollar tree. Also 2 of the Eva dry reusable dehumidifiers. A have a house size dehumidifier under my desk that I will also run if it rains outside and the humidity rises. I recently installed a cubic mini woodstove. I did it when it was freezing outside and probably 60°F inside. While I had the hole open in the roof I felt the underside of the metal. I don’t know if it was just then because it was exposed or it’s always been that way, but I could feel some moisture present on the metal. Not wet, not dripping or anything problematic, not enough to cause mold or anything; I could just detect it’s existence. So it’s important to control the humidity, because I bet if my humidity was high enough in the winter it would be raining condensation on the ceiling paneling from the underside of my roof and cause mold etc. But luckily it’s nice and dry :) no issues for me. The first camper I ever bought (a 1974) the guy had lived in it during the winter for over a year and didn’t control the moisture at all. It also leaked at all the seams. The roof beams, even where there wasn’t an actual leak, were covered with black mold from the condensation problem.

[@TrailerTrashtoTreasure]

Yeah, for full timers or folks in cold environments moisture control is critical. I always avoid cooking inside partially to minimize the moisture added to the air. In Kansas we also have incredible humidity in the summer; the dew in the morning can be as heavy as a light shower and soaks into everything. Controlling moisture is an ongoing battle, and I think anything you can do to further facilitate the natural drying process is time and money well spent.

[@michaelnelson2474]

I agree, no to the vapor barrier. As you said, it is more likely it would retain moisture, than it would prevent moisture from entering.

[@TrailerTrashtoTreasure]

Thanks! Plus I kind of feel aluminum is a pretty good vapor barrier, lol! But seriously the big worry is where does condensation go if it forms, so yeah, whatever I do, I want it to be able to evaporate and leave.

[@michaelnelson2474]

@@TrailerTrashtoTreasure it's the same reason I left the underside of my rebuild, uncovered and uncoated. The moisure needs to drip away.

[@TrailerTrashtoTreasure]

Exactly!

[@roar6428]

Typically, the vapor barrier should be on the warm side of the wall. In northern climates it's placed on the interior and in southern climates it's placed on the exterior. The reason for this; as temperature drops from the warm side to cold side, it can reach the dew point where moisture vapor would turn to water droplets on an impermeable layer. The moisture vapor needs to be able to flow towards the cool side and disperse. Not sure where you are located, but most likely you would be using the camper during the warmer times of the year. With that said, I would avoid using a vapor barrier so that any moisture vapor can readily transfer through the wall.

[@TrailerTrashtoTreasure]

Great explanation and sound reasoning!

[@dtmty]

make a video of the after a year with insulation, also if you can measure the heat inside and outside, would be great

[@TrailerTrashtoTreasure]

That's a good idea. I'll keep that in mind when I get around to finishing it.

[@barrydelljeremy8879]

Wool works the best. It releases moisture, isn't flammable, and of course warm. But it may be expensive idk i have so i use there wool so its free

[@TrailerTrashtoTreasure]

Yeah, wool is a nice alternative, but it's not always readily available to everyone.

[@willnellen9028]

Hi, I have a question. You say you use wool, but do you buy it or not? We have sheep ourselves and it would be something I can use, but my main question then would be, should I use it only after a wash and clean, or, just the raw wool itself, as clean as possible? (without running it through a wash cycle I mean.)

[@TrailerTrashtoTreasure]

I would think you'd want to wash it, but I'm not a wool expert so hopefully @barrydelljeremy8879 can chime back in.

[@alanday5255]

I love that pencil...

[@TrailerTrashtoTreasure]

They're super handy!

[@deborahfieldson5939]

So, I have a moisture question you might have insight into. I live in northern Calif, normally dry climate (think drought). I took my needs to be renovated 1968 camper out, the outside is in pretty good shape with the previous owner doing a good sealing job around the exterior, inside not so much...with rippling on the paneling and that's where my ugh, let's not go there. OK, so my question is, I went camping this wknd with temps in the low 40's and brief periods of rain. The interior walls were cold to touch, but everything fabric was damp, like very damp. The walls and metal parts weren't moist and I saw no indications of leaks. I only had small ceramic heaters and they were no match. My guess is more efficient insulation when I do the renovation and a better heat source, but how do you manage dampness or humidity? I've probably answered my own questions but, the interior dampness is just baffling. BTW, love your work.

[@TrailerTrashtoTreasure]

Okay Deborah! I've been thinking about this for several days and I think I may have an answer for you! Your cushions and whatnot may not have actually been damp. I thought about all the ways that they might have absorbed moisture when nothing else seemed to be condensated, and I didn't come up with anything that felt very compelling. So I got to thinking about how we sense dampness, and the truth is we don't sense it! We have no sense receptors for wetness; that's why water still feels wet even if you're wearing rubber gloves when you stick your hands into a bucket of water. Your brain infers dampness or wetness from a combination of temperature and pressure; that's why cold clothes often feel damp to the touch; it's that combination of softness and coldness that tricks our brain into interpreting dampness! That's the best I've got for you, but you know I'm not an expert in sense perception so I very could be way off the mark! Thanks for watching!

[@nvalles2565]

I think your heaters created humidity. You need to use dry heat. Wood stoves can do that.

[@TrailerTrashtoTreasure]

That's a good point. Ceramic or catalytic heaters will still add moisture to the air. A furnace or diesel heater or, yeah, a wood burner won't do that.

[@mrscrane4346]

Did you put those little spacers behind every single panel or just some of them?

[@TrailerTrashtoTreasure]

Yup, all of them.

[@jerrytalley802]

I wonder if the foil type HVAC tape, it would seal the foam panels and could cover the wood?

[@TrailerTrashtoTreasure]

You could use it, but I doubt it would give you much gain, plus you might end up over sealing the walls and trapping moisture where you don't want it.

[@ckkern6624]

Did you put the bubble radiant barriar on ?

[@TrailerTrashtoTreasure]

I haven't really finished this camper yet, but if I were to add a radiant barrier with the insulation I'm using, I would install it against the wood paneling so that there is an air gap between it and the insulation. The air gap is critical to getting any kind of r-value out of reflectix.

[@kiyamanus3723]

I think it will retain moisture and drip down and sit on your framing but who knows should last just fine. Way better build than these 40k ultra light trailers with disposable styrofoam floors that start sagging.

[@TrailerTrashtoTreasure]

More and more, my thinking is that the amount of humidity it would take to cause a damaging amount of condensation to form within the walls is just unrealistic. I did actually think about building a model to test condensation and vapor barrier placement under differing conditions, but that'd be just one more project to take up time. Regardless, I whole heartedly agree that any correctly rebuilt vintage camper is going to be better than most contemporary campers.

[@kiyamanus3723]

Yeah I don’t think you’ll have any issues in your lifetime lol Great build!

[@TrailerTrashtoTreasure]

Thanks! Someone else can worry about the next lifetime.

[@alexlindekugel8727]

most camper interiors that ive seen are vapor impermeable so vaper going threw interior to exterior shouldn't be a problem. and the thicker the wall insulation less likly for condensation. and considering how lose most camper exterior cladding is it should dry fast especially when driving down the road..

[@TrailerTrashtoTreasure]

Yeah, that's my thinking anyway! Thanks for watching!

[@lakestatebullies7391]

House wrap maybe

[@TrailerTrashtoTreasure]

I'm thinking Roberts Unison, but I'm not there yet, so that'll be in a future video.

[@jerrytalley802]

Have you looked at radiant barrier, would think that would do wonders to reflect the sun? One I used in my house was ATTIC FOIL. The reason I mentioned that is, it breathes, is super tough, and reasonable

[@TrailerTrashtoTreasure]

To get the maximum R-value from a radiant barrier you're supposed to install it with an air pocket outside of it for it to reflect back into. The thinness of a camper wall means you've really got to choose one or the other type of insulation, and we chose to go with foam, because I felt it'd give me a little higher R-value.

[@rodneyp9590]

@@TrailerTrashtoTreasure r value is overrated. That being said I think you’re right keeping it off of wood. Definitely a super important step in steel structures though

[@TrailerTrashtoTreasure]

I think a lot of folks expect too much when they go to insulating these campers. You simply don't have enough wall space to accomplish much.

[@CamperVanDreamBuild-ct5pl]

This comment helped me decide. I'm using 60mm foam for my build, and it comes with foil on both sides. I am researching whether I still need to use house wrap with that, but it seems like it would be overkill. Thanks for sharing your process@@TrailerTrashtoTreasure

[@TrailerTrashtoTreasure]

You might consider using Roberts-Unison underlayment instead of house wrap. It'll accomplish basically the same thing plus it's translucent so you can see what you're trying to track it to, and it'll add a bit of cushion between the framing and the skin. www.homedepot.com/p/ROBERTS-100-sq-ft-Unison-Premium-2-in-1-Underlayment-70-025/100541278

[@agentofficerthomasa.porter107]

Yes your wood framing is 1 1/2 inch you use 1 1/2 inch insulation & wrap over this your vaper wall wrap over this. You want to apply glue before put'n the insulation board into place.

[@TrailerTrashtoTreasure]

The thing with foam board is that you'll get some inductive transfer of heat if it doesn't have an air pocket between it and the interior wall. Alternatively, the nice thing about fiberglass is that inductive transfer is minimal. So I have kind of rethought things a bit, and I sort of wish I'd just gone with fiberglass, but I hate working with that stuff, it's just so itchy! I'll probably use fiberglass for the roof insulation, and I'm thinking I'll use Roberts Unison condensation barrier as Larry suggested in one of the previous comments. It's all still a work in progress.

[@lawrencefranck9417]

Wrong tyvek breaths one way..

[@TrailerTrashtoTreasure]

You know, I really don't know much about Tyvek, but looking on DuPont's website they say, "Tyvek® HomeWrap® and Tyvek® CommercialWrap® are non-directional and are equally effective if installed with the logo facing the inside or outside of the wall or with the logo oriented in any direction." I'd be interested in putting it to test though.

[@CamperVanDreamBuild-ct5pl]

I just jumped on the website too, and they say Tyvek is made of "high density polyethylene fibers randomly laid and compressed to form a remarkably tough printing substrate", and the word "randomly" seems to indicate that there is no particular direction or orientation to it@@TrailerTrashtoTreasure

[@TrailerTrashtoTreasure]

Yeah, I'd say it pretty definitively works in any direction.

[@willnellen9028]

@@TrailerTrashtoTreasure So, now I understand you're gonna use Tyvek (or some other brand of housewrap) between the outer shell and the insulation? Or am I wrong thinking that?

[@TrailerTrashtoTreasure]

When I finally get back to it I might make a few changes, but I do plan on using Roberts Unison Underlayment instead of something like Tyvek. It gives a little bit of cushion between the skin and the framing, and it's translucent so you can sort of see through it to see where you're tacking it down.