Uncovered patio made with cob

I am very new and my apologies if I have posted this in the wrong place. I am not only new to this forum/site,  but I am also new to the idea of working with what I have to create a better environment in a pre-existing home that is not in good shape. I am pulling down a deck that is very brittle and rotted. It in its place, I would like to put in a simple and low patio but I am interested in making it out of Cob. I would like to know if is this possible or recommended and if it is, are there instructions anywhere on the site on how to do this? It is a large area, approximately 16x12 feet.  I have watched many videos and read as much as I can online but cannot seem to find a direct answer on whether or not a patio built of this material would withstand the weather changes.  Thank you in advance for any help!

Welcome!

Cob when wet pretty much reverts to mud with some straw in it.

When reading about building with it you will hear again and again about the need for good 'boots, hat, and coat'; dry raised foundation/stemwall, good roof overhangs, and tough plaster or siding, all to keep the cob dry.


Unless you are somewhere really, really, really dry, this plan as it stands is probably a nonstarter...

I can share my experience and see if it helps:
Two summers ago I built 3 large raised garden beds from cob. I live in a semi-arid climate (though that seems to be changing). There has been minor erosion on the top tiers of the beds mostly due to a few heavy rainfalls and a bit of freeze thaw fracturing in places where I should have used a bit more straw in the mix.
To build "good boots" I dug down into the soil about half a meter and filled the trench with rubble, gravel and flat stones. I then dry stacked stone above ground level (about 30cm tall). Cob was laid on top of those foundations and there had been no erosion at ground level, even during the Spring snow melt.
As of yet I don't have a 'hat' on the beds, though I plan on doing a lime plaster for water residency.

What you are proposing is basically an outdoor earthen floor. Do you have the ability to source rubble and stone to build a tall foundation? Or earthbags or suber-adobe?
On top, you could lay flagstones into a lime mortar for weather resistant surface treatment, but even then I'm not sure how it would do with standing water, so you'd want to channel any water off and away. Maybe a linseed oil surface coat as well?

Anyway, just some ideas of how you might experiment with this idea. There are probably less laborious ways to build it (like reclaimed lumber), but please post your results if you decide to move forward!

If you do it right and consider drainage, foundation, and pooling of water you should be able to do it. You may need to resurface it every couple years amd apply bioled linseed oil to prevent water saturation and improve waterproofing. As for instructions, get a book called Cobers Companion by Michael G Smith. Best cob instructions i have ever found.