Great idea. I just had the same idea a few minutes ago and then searched to see if anybody had tried it. I imagine this was typical way back but lost favour to modern methods.
I live in Mongolia with my Mongolian wife. I'm originally from the UK. We're probably going to buy some land (about 1400m/2) that is forested with mostly Siberian larch. Apparently this is a naturally rot resistant species. We will probably build a ger platform on the land since it's a south-west facing downhill (about 9 degrees) lot. There are a lot of trees we'd need to cut anyway. Why not use the stumps, I thought, and the lumber for decking. This could save a ton of money since lumber prices have gone sky high due to covid and border closures. We'll first need a container for secure storage - gers (yurts) are not in the slightest bit secure - and that will need a leveling method. Then a ger (yurt) platform for 1-2 gers. If the first project is successful, then we can move forward with the platform for gers. Next year we'll probably build a simple house with SIP's which is pretty light too.
One tip I saw for posts in the ground, is to soak motor-oil mixed with diesel into the wood, then let it dry then coat with roofing asphalt. This won't help below ground but it could help to minimize water absorption above ground. Especially on the naked stump face. Mongolia has a dry climate so I'd expect the stumps to outlive me (I'm 58).
Let us know of your progress and I'll do likewise!
