The image below is a view from the first floor of the 2nd floor bath drain and supply system that sits in roughly the center of the upper floor.
We're building a new home in Canton, MI, and the plumbing was just roughed in by the plumber, but this drain arrangement looks odd to me.
Let's assume first that the drain from the Toilet is actually sloped 1/4" per foot (I have to go back with a ladder to check it). That horizontal run continues off the image for another 16ft before it comes to the soil stack at the outer wall of the house.
But, my main issue is the way they tied the Tub and Sink into the toilet. It seems to me that the Wye they put in should attach such that the tub and sink enter from the TOP of the drain line, not the side. With such a long drain across the house to the stack, I am concerned about waste in the toilet backflowing into the smaller pipes leading back to the sink and tub.
Also, not shown above the floor: The sink is vented in a wall, so I would imagine this makes a "wet vent" for the system--is that right?
Lastly, the entire system they put in has ONE pipe sticking out of the roof of the 2nd floor. I saw a 4" pipe through the attic to outside, but it immediately is reduced to about a 2" pipe, which then splits off all over the house horizontally to all the rooms needing venting. There is no 4" continuous stack from the basement up to the roof. After the pipes get up from the basement to the first floor, they get smaller and continue up to the attic to join this "manifold" in the attic before popping through the roof.
Any comments would help as you never know how well the city inspector looks at some of these things before signing off.
We're building a new home in Canton, MI, and the plumbing was just roughed in by the plumber, but this drain arrangement looks odd to me.
Let's assume first that the drain from the Toilet is actually sloped 1/4" per foot (I have to go back with a ladder to check it). That horizontal run continues off the image for another 16ft before it comes to the soil stack at the outer wall of the house.
But, my main issue is the way they tied the Tub and Sink into the toilet. It seems to me that the Wye they put in should attach such that the tub and sink enter from the TOP of the drain line, not the side. With such a long drain across the house to the stack, I am concerned about waste in the toilet backflowing into the smaller pipes leading back to the sink and tub.
Also, not shown above the floor: The sink is vented in a wall, so I would imagine this makes a "wet vent" for the system--is that right?
Lastly, the entire system they put in has ONE pipe sticking out of the roof of the 2nd floor. I saw a 4" pipe through the attic to outside, but it immediately is reduced to about a 2" pipe, which then splits off all over the house horizontally to all the rooms needing venting. There is no 4" continuous stack from the basement up to the roof. After the pipes get up from the basement to the first floor, they get smaller and continue up to the attic to join this "manifold" in the attic before popping through the roof.
Any comments would help as you never know how well the city inspector looks at some of these things before signing off.
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