Gutting second floor bath< what size pipe do I need for the sink and tub/shower? Have a 4" cast iron for the main.

Hi Jaybiss

Toilet gets 3" minimum.

Tub/shower gets 1.5" minimum

Sink gets 1.5" minimum.

How do you plan on venting everything? Is wet venting allowed in your area? If wet venting is allowed this can usually save you time and money...:) If wet venting isn't allowed then every fixture will need an individual vent (toilet gets 2" vent, sink and tub get an 1.5" venmt each) and the vents usually connect into the 2" toilet vent pipe and that connects to other 2" or larger vents or can penetrate the roof by itself.

Let me know...

Mark