Hey Guys, Hope you are enjoying AND reflecting this memorial day. I have a question concerning an install I am doing for a friend. I am not a plumber, but strive to have my work reflect a professional's touch. Anyhoo, my question pertains to a horizontal 2 inch waste line, in a residential home. I will try and describe the scenario as best I can, I can add pics later if warranted, or requested. I am dealing with a 2 inch waste line that runs horizontal about 11 ft in a relatively shallow and tight bulkhead. It drains into a 3 inch stack via a wye. Feeding into this 2 inch waste is a 2 inch shower drain(not vented)6 ft from stack, and a washer drain end of line 11 ft from stack(vented with AAV). After doing some research, it looks as though this may not meet code, and probably not best practice, as I consider most codes to be the minimum required. My thinking was the lack of venting from shower drain and the AAV as a washer vent would effectively reduce the fixture capacity of the 2 inch horizontal line. I was under the impression that the fixture load was assuming all fixtures had atmospheric vent. I am of the mind set that the horizontal drain line, where the shower drain inlet feeds should be upsized, but the space is very limited. Nor do I see a practical way to vent the shower. Is that two inch horizontal drain line adequate? Should I vent it separately through the roof? Any and all insight, and advice is greatly appreciated. I hope I'm not making a mountain out of a mole hill, I just like things to be done in a thoughtful manner. Much obliged