Question on SDR 26 sewer line running under house

On a very steep mountainous lot where heavy-walled SDR 26 gasketed sewer line is required outside of house by local town, we continued SDR 26 line under house footing and under future slab before sweeping up to connect to Schedule 40 drain line rough-in under rest of slab. Bedding is gravel.

State inspector has raised concerns about SDR 26, but based on rated burial depth (many 10s of feet) and well established integrity of gasketed fittings, intuitively SDR 26 should be okay. I believe some localities across country approve SDR 26 for sewer lines under buildings, but inspector claims under UPC 2006 must be Schedule 40 under slab.

Understand SDR 35 is not okay as it has thinner wall, but with thick wall of SDR 26 and associated stiffness, seems like SDR 26 with gasketed fittings should be bullet proof and arguably as good or better than foam core Schedule 40 drain lines under slab which are in common use locally.

Any experience / suggestions? Thanks!

What we think will mean nothing, it's what the inspector wants. Both he and you must go by the code in your area.

John

I'm allowed to stub outside the foundations with ABS, but not licensed for side sewers.

Likewise, the side sewer guys aren't licensed to be inside the foundation.

Does it make sense? Huh? Maybe not, but it's what we do.

I can ever work on the "city" sewer in the street or easement, as long as I have adequate insurance. I do not lide SDR for ANYTHING. Since its i.d. is LARGER than sch 40 pipe and fittings, it would still create a slight obstruction at every fitting.