Foam Core PVC
From Open Source Ecology
- Foam core is allowed for DWV applications, but not in pressure applications
- Not as strong as solid core - more deflection - [1]. But that actually makes it last longer, according to wikihow? [2] and this [3] explicitly stating it's longer-lived than solid core.
- Stack Exchange says it can bend more [4], some jurisdictions don't allow it but only in commercial construction.
- There is a significant difference for direct burial. Only 1/2" gravel or smaller is allowed for foam core. [5].
- Foam core is ASTM F891 [6] while ASTM D1785 is for solid core (pressure pipe) [7]