I am planning to install a new full bath in my detached garage. Currently I have gas, water and a small drain pipe for a laundry sink but I do not have the 4" sewer line required for the toilet. I need to add this sewer line for the toile and I have no idea of what would need to be done or what the proper way of doing it would be. Do I ran a long 4" pipe from the existing ones under my current baths all the way to the garage? or do I need to tap the main line somewhere? I have attached a picture of my house from the top indicating the location of the current and new bath to be installed.
I will have a plumber come by on Monday to provide me an estimate on the work.