Drain from Outbuilding

[Bluenose]

I have an outbuilding I use as a woodworking shop in Massachusetts. I have in stalled a laundry sink and put in a 2 inch drain back to the house and into the main sewer. An inspector has told me that I must have a 4 inch drain from the outbuilding to the house. I asked a licensed plumber his opinion and he said it would be no different than putting a sink somewhere in the house and having to run a 4 in drain frim the new sink to the the main drain.
Do you have an answer or opinion?

 

[John Gayewski]

I have an outbuilding I use as a woodworking shop in Massachusetts. I have in stalled a laundry sink and put in a 2 inch drain back to the house and into the main sewer. An inspector has told me that I must have a 4 inch drain from the outbuilding to the house. I asked a licensed plumber his opinion and he said it would be no different than putting a sink somewhere in the house and having to run a 4 in drain frim the new sink to the the main drain.
Do you have an answer or opinion?

They may have a minimum size four a building drain. The requirement likley has nothing to do with the performance of the drain and has more to do with them wanting a minimum size as a matter of uniformity. That way when you buy a building you know you buying a building that can accept normal plumbing. And normal building standards have been applied.