PVC SDR 35 or 28

[SMIAH]

Some regulators here ask for wastesewer pipe to be SDR35 PVC while drainage has to be SDR28 PVC.
I saw both to be SDR28 and some other ask for SDR28 for wastesewer and 35 for drainage.

I'm not sure to see where this all comes from. Any clues?

 

[bimr]

That does not make any sense.

Both products are made with the same raw materials. The SDR28 is a little stronger pipe than the SDR35 and would be an upgrade over the weaker SDR35.

I recommend that the SDR28 be used because the difference in cost is minimal.

 

[jgailla]

+1 for the thicker pipe. I had a contractor tell me that they ordered SDR 26 even when SDR 35 was specified because they had fewer problems during installation.
SDR 26 should be more common than SDR 28.