Originally Posted by pauliplumber
Why were drum traps so popular back in the day?
Is there any advantage over a P trap?
You have to realize what was at the end of a tub on legs.
An exposed waste 1-3/8". The tee that went up to the overflow
also went below the floor to a waste line. There was no trap abovethe floor, if a P trap was installed below the floor it was a major task to disconnect the waste to clean it out or replace it. The inventors of the day made a trap Drum Trap which prevented sewer gas from entering the room, but also allowed a clean out flush with the floor.
IMHO THAT WAS THE REASON FOR THE DRUM TRAP.
PS You can still buy them today in PVC/ABS from NIBCO although
the lid would not be flush with the floor.