On Feb 10, 1:36*am, "MiamiCuse" wrote:
I had some plumbing work done to relocate some drains, broke the 4" concrete
slab and the trench was 2' x 8', but the main drain was located in a
different location and in order to reconfigure properly, the plumber
eventually made a trench 4' x 12' in size. *This is a pretty big trench and
I don't think I can just put back the sand, compact it, throw in a layer of
moisture barrier and pour new concrete.

Do I need some sort of rebar or wire mesh? *If so any recommendation on
procedures?

Thanks,

MC

If you are talking about a floor slab, I think you are correct.
Even if the existing slab was not reinforced, I would assume the new
soil is not fully compacted.
I would do my best to compact the soil that is placed in the trench.
The slab you put over it will not be 'structural' and will break up if
the soil subsides.
Dowel into the edges of the existing slab and add some 'pencil rods'
to help the new slab span the disturbed earth.
T