As I mentioned in my first post, I will split the tasks which I need to work on.   I hope I am posting at the most relevant location, this post would be about the "insulation" of a granite house crawl space. The crawl space is about 30 cm deep. I have been advised to install/lay a heave gauge vapour barrier and put sand on it as an extra protection against vapour (joist wet root). When I started to read up on it, I came across a few different solutions: heave gauge