3

I am converting my music studio, with no utilities, to a studio apartment. With that said I am having to cut the slab to install the sewer. I am in Los Angeles and am wondering what is the correct procedure to backfill the trench to avoid settling in the long run.

Thanks for your help!!

Best, Matt

enter image description here enter image description here enter image description here enter image description here

FreeMan
  • 48,261
  • 26
  • 101
  • 206
Matt
  • 39
  • 2

2 Answers2

7

You need to use a tamper and tamp each 6"-12" of fill as you go:

enter image description here

It is also important that you have a plan to tie the new concrete to the existing slab, to help prevent independent movement. For mine we drilled horizontally into the edges of the existing slab and used epoxy to set bent rebar rods into it, then tied those to the rebar grid for the new concrete.

Jimmy Fix-it
  • 37,916
  • 35
  • 62
1

Use non-compressible fill - road base - on the inside.

On the outside I'd probably use road base and put some of the broken concrete in the hole avoiding voids.

Fresh Codemonger
  • 14,459
  • 3
  • 24
  • 57