interior wall strugles

[Carolina_coast99]

I know this has been discussed many times here but I am still trying to wrap my head around the potential issue of condensation on interior aluminum covered walls.
the reason I bring up is because I love the way interior walls/design on airstream trailers look. I want to go that direction when I begin my build but I am also doing everything I can to avoid any water issues...
how does airstream (or any camper/trailer) reduce/remove the issue of condensation forming on the interior walls in general? or does it actually form on these campers no matter...? I don't know. are there any airstream owners- current or past- who may tell me?
I plan to have a fair amount of insulation on my walls before the finishing skin is installed. (1/2" xps between the 1" ribs then 1 1/2" closed cell spray foam on walls/ 1" xps on ceiling between ribs and then 2" spray foam/ 2-3" spray foam under floor between joists)
any experience or information is surely appreciated

[tony.latham]

...how does airstream (or any camper/trailer) reduce/remove the issue of condensation forming on the interior walls in general?

My first teardrop had solid plywood walls. It had a condensation issue on cool nights. My teardrops since then, have had insulated walls (and ceilings). Just like your insulated house, no condensation issues.



Tony

[McDave]

The condensation happens where warm moist air and cold meet. If that is in the air you get fog. If that is on metal or glass either frost or droplets. If the interior wall is close to the same temp as the inside air, no condensation. It sounds like you will have plenty of insulation and little to none cold air infiltration. Look into " vapor barriers". Most rigid polyIso sheets have a foil face or two to act as a barrier. Also, if you are using propane heat you should vent to allow excess moisture out. If you have a full house of people sleeping in there moisture from respiration can also build up so a vent is wise.

McDave

[Ottsville]

The two above hit it on the head, insulation and air flow. Keep in mind that if you have metal framing that your interior cladding is attached directly to you will have a thermal bridge there and condensation will collect on the walls where the framing is.

[Carolina_coast99]

thanks to all of you for breaking that topic down for me to be able to understand better. im sure I had read something of the similar during my research but it never clicked. now I get it...……..I think- haha.

im not using propane for heat. i plan to have a duct-less HVAC system (mini split).

my xps foam board has no foil facing/backing.
here it is:
https://www.homedepot.com/p/Owens-Corni ... /207179253
should i look into putting one over the foam and underneath the aluminum skin?

is this product something of the right idea for a vapor barrier...?
https://www.lowes.com/pd/Blue-Hawk-100- ... lsrc=aw.ds

[tony.latham]

should i look into putting one over the foam and underneath the aluminum skin?

Nope.

T

[McDave]

Agreed. XPS is a different product than the poly iso foil faced. XPS is resistant to moisture/vapors. You do not want to trap any moisture inside the wall. Just tape the edges or spray foam any gaps. I believe for max insulation benefit a 1/2" air gap between outer skin and XPS is recommended. You might want to verify that per manufact. installation instructions.


McDave

[Carolina_coast99]

Beautiful.
thanks guys.