One way to build a suitable superstructure would be to do so in discrete, pod-like units - placed end-to-end/side-by-side with space between them to accomodate raft flexing. Flooring between units to be fixed to one unit but free floating over the next - bridging the gap required for flexing. If required to provide for a closed external wall the the same idea could be employed here(ie: the walls would look something like the scales on a fish from the outside).
Yes, from a modern standpoint but totally unfeasible for a bronze aged people whose "knowledge" was a flat earth, a water canopy, the sun & moon as lights and the feasibility to reach Heaven by building a tower.
There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969
Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008
If your local flood was big enough to cover the known world of the time, it would most certainly have had to cover Ararat, just as the text implies.
Try this. What if the flood story was actually the composite of 2 or more earlier stories that got intertwined. This would explain both a local flood & the "Ark" resting on Mt Ararat. There is some evidence of a large meteor or asteroid striking off the coast of Madagaskar about 5000 years ago. A Tsunami could have pushed this boat up on Ararat. The second story is of a boat, carrying animals getting caught in a severe rainstorm. The composite story gives the whole story a world wide flood scenario considering that the story teller's view of the world would appear that a local flood covering all he could see would be, at least to him, the whole world.