rice hull insulation, condensation, vapor barriers inside metal walls?

I put this in tiny house because i'm expecting this to go into a tiny house of some sort, but this could apply to anything.

So i'm planning my tiny house - it could be a semi trailer, sealand container, school bus, or a maybe 12 foot wide A-frame on skids. (the width being set by something road legal with a simpler permit if I could get it up onto a flatbed to be moved)

Even if it's the A-frame i'm strongly thinking of METAL walls - simple cheap corrugated iron, like in africa.  This isn't a 30 year house, this is a "last me until I can get the real house built" thing for let's say 5-10 years hopefully worst case after which we decide what to do with it.

If I build an A-frame i'm wanting to use loose rice hulls as infill insulation.  Using "the wisdom of stick built houses" (see my other post) I just want outer corrugated iron, drywall, sawmill cut lumber, and filling the space between pouring in rice hulls after we've run some basic wiring and such thru there.

If this was inside the trailer/skoole/container it's the same - METAL outer wall, drywall inside, rice hulls poured down inside.


I'm worried about condensation issues in minnesota cold.  Rice hulls are supposed to be moisture and I think mold resistant, but that doesn't necessarily mean i'd want them getting randomly wet without drying out.  Since rice hulls isnt one solid piece like styrofoam i'd think the temperature would have a bit of a gradient inside the multiple inches of wall, crossing the dew point somewhere in the middle, I don't know if there would be condensation outside, inside, or just get the middle a bit moist.  I dont know if vapor barriers would have a point - or should still be used.  Any insights to share?

How will you pour the rice into the A frame and not lose any ?
Would recycled polystyrene sheets be easier?

hello, i have not used rice hulls but i did try this idea out using chopped miscanthus grass ,and  then vermiculite granules but unless you can totally seal off the entire product from moisture against the sheeting , it will draw condensation in where ever you miss  sealing it and leak water down the sheeting behind the hulls. You can see in the use or the practice  of the method used by several companies ,that spray a polyurethane foam onto sheets  in a retro fit of stopping condensation drips off the sheets of iron   ,or the sheets that are sold with a 50mm thick layer of foam bonded onto them at manufacturing , not that i would advise the poly foam . I have used a diy method by making up a hempcrete style mix and by  making a spaced out shuttering system ,to then loosely pack this up against the sheeting and the shuttering . Hope this makes sense ,cheers ,tony