Clay plaster as structural sheathing in a tiny house on wheels?

Anyone know of examples of clay plaster being used as structural sheathing on a conventionally framed tiny house on wheels?? I know of people using clay finishes on the interior, but what about outside the framing?

I’m thinking about it.. I wanted to do Hempcrete but sourcing the materials is still a challenge.

I also wanted to do post and beam but seems too heavy for the trailer.

So I’m going with conventional stick framing but really am trying to find alternatives to plywood that will still provide structural shear. I’ve looked into MgO but am not going to go with that choice...

So I just read how clay plaster can be structural and I’m very interested. But will it be too heavy?

I think the plaster will crack as soon as you move the house. Also, weight is a serious concern.

I've seen two portable clay plaster structures. The first was in the UK and I cannot for the life of me find it again, but the other was done by the Canelo project. https://caneloproject.com/projects/tiny-house/

I haven't seen it in person, but it is a beautiful structure.

My immediate thought would be that the plaster would crack with any sort of towing, but Athena Steen is so experienced, she would know best.

Athena is the expert that settles the issue. I knew her on the strawbale listserv in the early to mid nineties. I rest my case.

It is not clear to me that Athena puts this structure on the road the way some "tiny home on wheels" folks would.   They may have only expected to use it's "on wheels" aspect to resituate "on property"...  

This is a totally reasonable use-case.

Regarding the OP seeking sheer strength from this... my own experience with clay plaster suggests that it would be hard to get much if any shear strength that way.   Perhaps using expanded metal lath (as for plaster) secured to framing would provide good shear strength in itself, but anything less (chicken wire, hemp fabric, etc) would probably not provide much, and very likely not enough to prevent mechanical damage to the plaster embedded in it.

I have ideated on natural building materials for mobile structures and have accepted that A) I'd need to use something more positive for shear (criss-cross strap/wire in every wall) and I'd plan to re-surface any earthen plasters after a significant move.   I have considered staggered 2x4 wall-joists with clay-straw infill and clay plaster finish internal and externally.  But as pointed out above I think I'd probably go for expanded lath over the straw-clay infill to give the plaster as much rigid support as possible.

I'd love to hear anyone else's experiences/experiments here!  

I would be hesitant to drive down the road with a palster surface on a structure. I have used Polymer Plaster on a section of strawbales that were used as a garden wall. In that case I wasn't concerned with the structure being able to breath but with no overhang (roof) the polymer plaster is unaffected by weather and the visual appeal is there. I acquired the Polymer Plaster from a painting company that had extra from a shopping complex project and took it rather than have them dump it in the landfill. That surface would stick to a THOW and with a mechanical anchor lath/wire I think would travel well. It's characteristics would have a far greater shear strenghth than conventional or earthen plasters in my experience.

Steven writes:

...I'd plan to re-surface any earthen plasters after a significant move. I have considered staggered 2x4 wall-joists with clay-straw infill and clay plaster finish internal and externally

Wonderful exploration! The ability to rework the mud -- wet, scrape, shore-up and re-plaster -- is what makes earthen building materials so easy to renew. After the move, just wet down the surface and replace that mud: good as new.
The clay-straw infill idea gives me pause. Given that you will have structural integrity with the 2x4 framing and expandable lath (or chicken wire, or some other biodegradable netting), would you consider using straw without clay as the infill? Straw-only may reduce travel weight and improve insulation. What is the benefit of clay-straw over plain straw for this application?

My hesitance about over the road travel and a traditional plaster coating would be the safety of others on the road. An on property move wouldn't worry me. Being able to repair the coating would be simple. Smacking a cyclist or anyone with a chunk of plaster wouldn't be a good thing.

Excellent point Robert: safety first!
Given that this is a tiny house, my first inclination is to wrap the building before moving it. Given that this is permies, coming up with a biodegradable alternative to plastic wrap seems like a terrific brainstorm.

@amy: Yes to probably allowing for straw-only.  This all started with a semi-portable shed building that I wanted to insulate with no significant internal shear-sheathing... the clay-straw would provide it's own support and could clay-plaster right over.  I don't know how much work has been done in reducing clay-content to the minimum, just enough to prevent settling in the straw?

@robert - I agree with not driving down the road shedding chunks of mud plaster.   Where I live, unfortunately (true of many rural locations) there are lots of road-hazards falling off of vehicles... mostly people headed to the landfill without proper tarping, but also gravel trucks and of course mudbogging offroaders throwing chunks of mud (wet and/or dry) as they return to "civilization"...

I do think if I had a (low-speed on-property) moveable structure covered in mud plaster I'd agree to the principle of wrapping it before taking it on the highway (if ever). I'd probably give it a tight wrap with a tarp, though the wind-whipping such yields might aggravate plaster breakdown... maybe bird-netting or chicken wire  would be better,  nothing bigger than a pebble getting loose?