Basement slab pluming... Mistake?

[Brendan Poirier]

I did my basement slab plumbing last winter. Continuing on the project this year and I will be doing the floor tile in the next month or so.

We are on a septic tank so we had to install a sewage ejector pit. The photo here shows the routing of the shower to the left and the washer will be next to the jackhammer. From the main 3 inch line I ran a 2 inch drain to the fork in the slab, then a WYE and a 2 inch drain to each the shower and the washer. Each fixture will have their own 2 inch vent, connecting above the shower and sharing a 2 inch riser to the attic before connecting to the main 3 inch stack for venting.

the 2 inch section running from the WYE to the main is about 5 feet before it goes to 3 inch.

I am now realizing that maybe using a 2 inch pipe to connect the 2 fixtures tot he main 3 inch drain was a bad move and it should have been 3 inch. According to NPC (Canada) , this is allowed as a washer is counted as 2 DFU and the shower as 2 DFU with the 2 inch pipe being able to handle 4 DFU

My main concern is the pipe being overloaded if both were being used simultaneously. If this needs to be fixed, now is the time before I tile the floor.

Looking for some input.

 

[wwhitney]

As it complies with your plumbing code, I wouldn't worry about it. There is one US code that says that after the wye the drain should be 3", but others don't, and I'm not aware of any history of problems.

On the shower venting, is the shower on the other side of the wall on the left side of the picture, with a dry vent takeoff rising straight up into that wall?

Cheers, Wayne

 

[Sponsor]

 

[Brendan Poirier]

shower will be on the closest side of left wall, dry vent rising up to the floor joists, then horizontally to meet the washer vent. they will connect together to rise up to the attic via a single 2inch vent. then connecting to the main 3'' stack for venting

 

[Reach4]

shower will be left side of wall, dry vent rising up to the floor joists, then horizontally to meet the washer vent. they will connect together to rise up to the attic via a single 2inch vent. then connecting to the main 3'' stack for venting

I think you are planning on horizontal dry vent for the shower. https://terrylove.com/forums/index.php?threads/shower-venting-sanitary-tee-laid-on-its-back.66233/ discusses whether that is allowed in Canada (not sure if that was conclusive).

Adding a lavatory could let you use a horizontal wet vent to vent the shower, and everybody likes those.

 

[Brendan Poirier]

I think you are planning on horizontal dry vent for the shower. https://terrylove.com/forums/index.php?threads/shower-venting-sanitary-tee-laid-on-its-back.66233/ discusses whether that is allowed in Canada (not sure if that was conclusive).

Adding a lavatory could let you use a horizontal wet vent to vent the shower, and everybody likes those.

It will have some horizontal runs yes. From what I have read, you are allowed horizontal venting in quebec canada where I am located. Also, the sink will be on the opposite wall so running a vent to it is not possible