cordwood disks over earth floor

I've read about putting tile or rock over earth floors, but what about cordwood rounds? The thought is 4 to 6 inches of gravel packed, waterproof membrane, a 4 to 6 inch layer of cob with inset floor heating, a layer of mortar mix used for grouting cordwood floors, then the cordwood rounds.

Any flaws with this system? Any ways to improve on it? ... Is it even doable?

I have done it, but there are a few issues.

The first is that the wood has to be well dried because if not, it will shrink and cause loose cookies, and a gap around them. Because of that same reason, the bark should be removed. It will just fall off when the wood shrinks from drying. Another issue is that cracks form in the cookie after it is dried. This can be fixed by filling in the wood with wood filler though, or my favorite wood filler...Bondo. It says right on the can, "can be used for wood".

This was a very common flooring back in the old days when machinery had babbit bearings and used lard for bearing grease in factories. The wood, having the end grain up, would readily soak in the grease making the floor less dangerous to walk on. To make it they used wood with limited commercial value: here it being eastern hemlock.

If I was to do another floor like this, I would take my logs and saw them into consistent beams first so that they were square in shape...say 10 x 10 inches just to make laying the floor easier. My first floors were made out of round cookies. Then I would cut those beams into 4 inch thick pieces. Because of their shape being square, I would not have to infill around them, but rather could place them right up against one another, using screws toe-nail fashion into the next so that that they were secure. I would then sand the tops of the floor with a floor sander to get the floor smooth. I would apply a finish to prevent the floor from being stained, but that is personal preference.