Solarpunk

Yes and no. There are grades, variations of acidity and oxidative state of medium through the year. It's heavy. It warps differently from everything else with temperature variation. Most of all, it is expensive.

I was also considering glass or clay overlapping tiles. Would be cool to cast huge ceramic panel, but it will crack, unless soil matrix holds it together. Shingles under sod might get roots growing through.

Another possible approach would be to allow leaks deliberately, then leave porous medium below the locking level with airflow access - so that any leaked water would be carried away with warmer air rising from habitation levels or even rhtough ventilation system or stove exhaust.

So much to study.