>>7702620>Eventually anything other than a stone slab would disintegrate no?Everything disintegrates if you're using it as a roof.
Scandis used birch logs for their roofs. That layer of sod on top is used to hold the logs in place like a layer of glue/mortar. So you just replace the roof as the logs age, like any other wooden roof. Green top is supposed to help the logs against draught and doubles as an okay insulator on cold days.
I like that the practice is coming back, at least among the hippy dippy eco-home community.