Drum trap pipe size

Questions, answers and advice for people who own or work on houses built during the 20th century.

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grb
Posts: 1
Joined: Tue Jul 27, 2021 11:20 pm

Drum trap pipe size

Post by grb »

Hello all,

First time homeowner of a 1937 home. I noticed the shower drain was slow, so I got into the access panel behind to find a drum trap. Opened it up and noticed the trap had a different size united inlet and outlet. The inlet looks to be 1 1/2" cast iron and the outlet appears to be much smaller, maybe an inch or so. The water gets backed up there. I've snaked all the way to the stack. The sides of the outlet are clean so it doesn't appear to be buildup. No issues with the sink or toilet (both of which are between the stack and tub). Is this a normal occurrence in older homes? Never seen anything like it but I've only ever worked on newer construction.

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