Waste plumbing size

[Ryan Stouffer]

Does anyone know if there are any codes on the size of the waste plumbing underneath bathroom sinks. I inspected a home today and the the waste plumbing diameter was 1-1/4 inch. It seemed a bit small. I think they are usually 1-1/2.

Thanks,

Ryan

[Michael Garrity]

I -1/4" is the min

[Michael Garrity]

until it reaches another fixture then the size increases