Hello , Im going to back fill a trench in slab . Should I pour in some concrete in the bottom of the trench here and there to hold up the pipe before backfilling trench with dirt ? Also can I encase part of the abs in concrete if I wrap the pipe first ? Thanks Spanky

Hi Spanky:

I would recommend that you take some wood and temporarily hold up the pipe until you can compact some dirt in and under the pipe. After most of the dirt is compacted and pipe is well supported you can pull the wood supports and compact in more dirt to fill the voids. If you use concrete to do this and then leave the concrete it would almost be like leaving rocks directly under the pipes... certain to crack/break the pipe over time.

In terms of encasing the ABS pipe in concrete, it is not a common practice to have plastic pipe in concrete as it expands and contracts at such a different rate than concrete that it usually leads to cracks in the concrete, but if you encase it in a strong wrap of insulation, for example, you may be able to pull it off just fine... maybe?

What is this ABS pipe connected to? Let me know...

Mark

Hello , Its hooked up to a shower and a floor drain.. Thanks