4" is fine if you use 3000lb concrete for slab on grade. 8-10" is for
foundation walls.
wrote in message
ups.com...
My contractor has specified a 4" thick slab on grade for a new garage
floor. Is this the accepted thickness? I've read that driveways should
be 5" thick and house foundations 8-10" thick. The plans *do* call out
reinforcement.

Comments?