Vapor Barrier and Air gap Ideas

[Michelle (GMC Gypsy)]

Ok, after watching a lot of YouTube and reading articles and forums this is the idea I have for insulating my van. Any suggestions on improvements will be appreciated.

I'm thinking bubble wrap (the large bubble kind) against the skin of the van (bubble side out, flat side in for circulation) then polyiso (foil side in or out?). Would I still need reflectix or a sound deadener? If so, where would the sound deadener go? Between the bubble wrap and polyiso is my guess.

Voices of experience needed.

 

[rvpopeye]

I'd just do it all with polyiso and call it good.
Thickness would depend on how cold or hot where you want to be is.
YMMV

 

[Michelle (GMC Gypsy)]

Thickness would depend on how cold or hot where you want to be is.
YMMV

I want to be EVERYWHERE!    But I do have it in my mind to be, basically, a snow bird. North in the summer, south in the winter. There will be exceptions for holidays, visiting family, but basically want to be where the temp is in the 70's during the day and cooler at night.

Would the backing on the polyiso be enough vapor barrier?

 

[GotSmart]

Put in a roof vent, and do not worry about getting fancy with layers.  There is a layer of waterproof steel on the outside.  A single layer of poli, double sided if you can find it, should do the trick.  If you will be in extreme climates a plastic sheet under your interior siding is always a good idea.

 

[Almost There]

What you 'insulate' with depends entirely on the lifestyle you intend to lead!

Need protection from the cold - then insulating with polyiso is the solution. Use 1/2" thick in multiple layers because it bends better around the curves of the van. Overlapping the layers so that you don't end up with the seams all in one place is a good idea.

Need protection from the heat - then reflectix over a dead air space (bubble wrap) offers that when done properly.

Need both - then layer from the van skin in - bubble wrap; reflectix; polyiso.

For example, I never intend, and will do anything I have to, to stay out of the cold (anything below 35-40 is too cold IMO). I was more worried about moderating heat because I know only too well how hot the inside of a van can get on a hot sunny day. I chose to only install bubble wrap/reflectix and skipped the polyiso entirely. So far so good!!

People living in more northern climes who can not just escape by driving somewhere else, well, they need more insulation from the cold and less worry about heat!

 

[Michelle (GMC Gypsy)]

Need both - then layer from the van skin in - bubble wrap; reflectix; polyiso.

Yeah, this is kinda where my thoughts were. I'm pretty ok with colder temps but I hate getting hot enough to sweat. I saw a lot of people using the reflectix straight on the skin of the van but my old science classes kept telling me that a layer of air between would be better insulation against the heat. I am leaning heavily toward bubble wrap, reflectix and polyiso just to get the best possible results the first time. I hate having to go back and re-do something because I skipped something that turned out to be needed.

 

[Almost There]

Yeah, this is kinda where my thoughts were. I'm pretty ok with colder temps but I hate getting hot enough to sweat. I saw a lot of people using the reflectix straight on the skin of the van but my old science classes kept telling me that a layer of air between would be better insulation against the heat. I am leaning heavily toward bubble wrap, reflectix and polyiso just to get the best possible results the first time. I hate having to go back and re-do something because I skipped something that turned out to be needed.

Your old science classes have done you good!!

 A lot of people don't bother to even go to Reflectix web site and read. Thermal insulation ratings vary from nothing to really good depending on what it's installed in and how it's installed.

Since they don't have a section on mobile living the closest comparison to installation is in a steel building like a quonset. A dead air gap is definitely required to provide a heat barrier.

Here's a link to my build thread where I showed how I installed the reflectix:

https://vanlivingforum.com/Thread-Building-Arabella

 

[Michelle (GMC Gypsy)]

Just read the entire thread on your build. Great job! I don't have the money to get that fancy on my interior since my van is 27 years old and 181K miles on the engine. Most of the money I get from selling my car (after paying back what I borrowed to buy the van) is going to go toward making sure it's mechanically sound. Breakdowns suck. I have countertop that's already in the van but it's covered in car paint so I'm researching paint removers.

I was thinking about renting a jig saw when I get to that point. Do you think it was worth it buying one or would you have rented one if you'd had that option?

 

[Almost There]

Just read the entire thread on your build. Great job! I don't have the money to get that fancy on my interior since my van is 27 years old and 181K miles on the engine. Most of the money I get from selling my car (after paying back what I borrowed to buy the van) is going to go toward making sure it's mechanically sound. Breakdowns suck. I have countertop that's already in the van but it's covered in car paint so I'm researching paint removers.

I was thinking about renting a jig saw when I get to that point. Do you think it was worth it buying one or would you have rented one if you'd had that option?

Buy one!

They are not expensive. Here's a link to HomeDepot page- either of the first 2 will do fine, no need to go for the $99.00 one...

http://www.homedepot.com/b/Tools-Hardware-Power-Tools-Saws-Jig-Saws/Corded/N-5yc1vZc292Z1z141kh

You also won't get a build of much of anything done in a single weekend so there's no sense in renting one.

Better yet, borrow one... :angel:

Oh, yea and buy a big package of mutiple types of blades for it, you'll need them!

You also might find that by the time you're put money in to paint removers and a lot of time and elbow grease, that you'd be better off replacing the countertop. I wanted mine done in laminate but couldn't find a part sheet and wasn't buying a full sheet so mine is 1/2" plywood that a girlfriend did a faux marble finish on for me. I make sure I protect it with pot trivets all the time because it's not heat resistant but it works for me and looks great.

 

[Michelle (GMC Gypsy)]

I was just on YouTube and re-watched Bob's video of your van. I didn't realize until I started re-watching it that it was you. I got an idea from your van the first time I watched it in regards to the toilet. I looked up the C Toilet and saw how much they cost and said nope. So I got to thinking about how it could be done a lot cheaper. It's basically a basin with the back missing to drop solids into what amounts to an old fashioned ice cream churn and a drain on the front that goes into a jug for the liquids. Finding an old fashioned ice cream churn could be problematic and the way the churn is set up the solid would likely drop onto the mechanism. So, I was also looking at ways to wash clothes and found this: http://www.justforappliances.com/Th...-Wonderwash-5-Lb-Load-Portable-Washer_i460607

I think I can use that for the solids since the hole looks big enough and you "churn" it by putting the lid on and rotating. Now I just need to devise a way to separate liquids and solids.

 

[akrvbob]

I think I can use that for the solids since the hole looks big enough and you "churn" it by putting the lid on and rotating. Now I just need to devise a way to separate liquids and solids.

I just pee in a pot of some kind, then poop. Or, if I suddenly have the urge to pee midst poop, I just get a bottle and pee into it. 

Maybe it's different between men and women, but I don't think so. Of course it's much easier for a man to direct his urine stream, but would something like a woman's urinal work for a woman? The urethra is still a long ways form the anus. 
Bob

 

[Michelle (GMC Gypsy)]

It absolutely would! I'd heard of She Pee before but not often enough for something like that to pop into my head. Thanks for the suggestion.... even though we've strayed quite a bit off topic.

 

[ilovemyvan]

It absolutely would! I'd heard of She Pee before but not often enough for something like that to pop into my head. Thanks for the suggestion.... even though we've strayed quite a bit off topic.

Staying off topic: I prefer an old liquid detergent jug, no flow control required. It's also "stealth" on your way to dispose of it. :blush:

Nicole

 

[flying kurbmaster]

It absolutely would! I'd heard of She Pee before but not often enough for something like that to pop into my head. Thanks for the suggestion.... even though we've strayed quite a bit off topic.

I think they are called "She Wee"

 

[Michelle (GMC Gypsy)]

I think they are called "She Wee"

Yep, my bad...  :blush:

 

[Shamu]

What you 'insulate' with depends entirely on the lifestyle you intend to lead!

Need protection from the cold - then insulating with polyiso is the solution. Use 1/2" thick in multiple layers because it bends better around the curves of the van. Overlapping the layers so that you don't end up with the seams all in one place is a good idea.

Need protection from the heat - then reflectix over a dead air space (bubble wrap) offers that when done properly.

Need both - then layer from the van skin in - bubble wrap; reflectix; polyiso.

For example, I never intend, and will do anything I have to, to stay out of the cold (anything below 35-40 is too cold IMO). I was more worried about moderating heat because I know only too well how hot the inside of a van can get on a hot sunny day. I chose to only install bubble wrap/reflectix and skipped the polyiso entirely. So far so good!!

People living in more northern climes who can not just escape by driving somewhere else, well, they need more insulation from the cold and less worry about 

Hi Lady, I have a question about insulation.  I'm new and doing my first  van. Any help would be appreciated.  I also just need to insulate for heat. Would the double sided reflectix be enough?

 

[surfmore72]

Wait... Is the bubble wrap the air gap?!   Here this whole time I was thinking it wasn't (still allows conduction through the plastic)...

 

[highdesertranger]

plastic is a poor conductor. think of hot and cold conductive transfer like electricity. if something is a good conductor of electricity it is also a good conductor of hot and cold. if something is a poor conductor of electricity it is also a poor conductor of hot and cold. highdesertranger

 

[surfmore72]

plastic is a poor conductor.  think of hot and cold conductive transfer like electricity.  if something is a good conductor of electricity it is also a good conductor of hot and cold.  if something is a poor conductor of electricity it is also a poor conductor of hot and cold.  highdesertranger

Not quite sure why that thought had escaped me!

 

[DannyB1954]

I disagree with the electrical / heat comparison. Although it may coincide in some cases, it will not in others. Pure water does not conduct electricity, but moves heat rather easily. Plastic is not a great heat insulator unless it traps air within it like foam. A plastic bottle does nothing to keep a beverage hot or cold. Glass does not conduct electricity, but it is a terrible heat insulator. Everybody does their best to cover windows to either keep heat in or out. They make double and triple pane windows because the gas between the layers insulates, not the glass.

I am probably also going to be at odds with common knowledge about vapor barriers. If there is a waterproof layer and water does get behind it, (from say condensation), how is it then to quickly evaporate? In my view if it can get wet easy, it can get dry easy. Since the inside of a vehicle is usually dry, one is better off not having anything that can keep moisture from evaporating when it does get wet. Take some wet rags and put them in a plastic bag, see how fast they dry. Put that moisture behind a water barrier panel and next to metal, you will get rust, or mold.