I've never run across this symbol before. It is on a hand drawn (heaven help!) foundation plan I have been asked to redraw in a CAD program.
On the left side is a 12"W x 24"D, Reinforced Conc. Turn down Slab. On the right side is 4" Reinforced Conc. Slab. with 6x6 1/10 WWM on 6 mil vapor barrier over crushed gravel.
I am assuming it means there is a 1'-10" elevation difference between the two slabs, with the lower side on the left. Is this correct?
Thanks!
MichaelCAD