Assalam-o-alaikum
I have to design a room(To block Radioactive Rays) with 6-ft thick concrete walls all around , 6-ft thick concrete base and 6-ft thick concrete roof slab as well.
Room Size (clear space) is 20' x 20' .
As far as 6-ft walls and base is concerned, it makes some sense but is it possible to pour a concrete roof slab 6ft thick?