2"
No and yes. Amendment (not from a professional plumber!): If you were simply running the sink drain into the shower drain and if there was not a reduction in pipe size, I would think you would be able to do that. I think the reason you need a trap for the sink has to do with code that requires a trap be no more than 24" from the basin to the trap arm. That being said, the pedestal sink in my house does not have a trap until after it drains below the floor.
Depends on the mateiral you already have (PVC) Galvanized nippe and brass P trap or rough brass connectiong to the trap and then of course what size of drain basin, KS, Slop Sink
Most of the time it is 4 inch.
downstream of a closet bend within 8 ft for three inch pipe and 10 feet for 4 in pipe at least half the size of the drain... unless it is stack vented then it would be full size of the stack right
The standard kitchen sink drain pipe size is 1 1/2 inches in diameter.
The size of a standard sink drain pipe is typically 1 1/2 inches in diameter.
A standard sink drain pipe is typically 1 1/2 inches in diameter.
The recommended size for a sink drain pipe is typically 1.5 to 2 inches in diameter.
A 1.5 to 2-inch diameter pipe is typically used for a sink drain.
The standard size for a sink drain, specifically for a 1 1/4 sink drain, is 1 1/4 inches in diameter.
The recommended drain pipe size for a residential kitchen sink installation is typically 1.5 to 2 inches in diameter.
The standard kitchen sink pipe size for most residential homes is 1.5 inches in diameter.
The standard shower drain pipe size for residential bathrooms is typically 2 inches in diameter.
The standard shower drain pipe size for most residential bathrooms is 2 inches in diameter.
standard size for bathroom sink drain is 1-1/4 standard size for kitchen sink drain is 1-1/2
The standard washer drain pipe size for residential washing machines is typically 2 inches in diameter.