So early on I tried making a bridge over water by laying slabs over the gap, and quickly discovered that even though the edge of the bridge (where they’d be building) was always easily accessible, they found it necessary to build ladders through the water up to the slabs anyway. It was incredibly limiting and maybe a little impossible, which I took as a gentle hint that I wasn’t supposed to bridge water that way.
Since then I’ve run into the same situation doing a number of things that seem like reasonable building projects, though. Manually created roofs and balconies both suffer the same problem, which can make even a small amount of floor/ceiling space extremely time-consuming to build.
I honestly can’t tell if this is an intentional balancing mechanic or if it’s just the hearthlings making very poor decisions. Does anyone know?