Need Building Code for Shower P-Trap in CA

[buzzzzoff]

I need the building code that requires an owner to have a Shower P-Trap in California.

[LiQuId]

its in the plumbing code not the building code, and all fixtures must be served by a vent and a trap is the jist of it

[buzzzzoff]

I was renting a house built in the 1920's and they claim it was not required back then. Is that true?

[LiQuId]

it is possiblle but any renovations would require the building be brought up to code. as far back as 1920's it would have been sufficiant to install a building trap, beyond that i dunno