My personal experience in construction is to use the chairs. Yes, the pull it up as you go method is OK, but as you get going with the pour I always worry about the reinforcement ending up in the bottom of the slab without support. What size bar is that? #4?
If for some reason you miss pulling up a few spots, then you've wasted your money and time on putting the rebar in and it does nothing for the concrete strength. This is also a PITA with WWF.
If for some reason you miss pulling up a few spots, then you've wasted your money and time on putting the rebar in and it does nothing for the concrete strength. This is also a PITA with WWF.