I'm in the process of tying rebar for a slab floor and never even gave much thought to the spacing of the tie wire. I do know that ideally you would tie it together every where it crosses. The re-bar is spaced 12" apart on a 32 x 32 slab. I'm thinking that all the way around the perimeter, everywhere it is overlapped together and then every 4 or 5 feet should be adequate and that the idea is to keep it from shifting when concrete is poured... does anyone know of code or rule of thumb for where to tie rebar? This will be a 4" slab for a hydronic radiant heated floor