DWV for new basement bath and laundry

[Theory]

Hi Guys,

I just moved into our first house last week and we are re-doing the basement and adding a half bath. I've attached a sketch showing the old and the new.

Due to the laundry/bath config there will be a long run around a wall to the main drain,~15'-20'. I was hoping if I used the right fittings and venting setup this would work: 2" drain shared by the laundry stand pipe and the lav sink.

Do you see any major concerns?

I appreciate the help. I've been trying to wrap my head around venting/draining for the last week trying to figure out the setup. It was very hard to find a spot to accomodate the dryer vent, and plumbing venting which is why I'm not left with many options.

Here is a nice link to Bert Polk's plumbing tips

[Hammerlane]

Are you eliminating the laundry sink? I do not see it in the new diagram

[Theory]

That's correct. Eliminating the sink with the 1.5" drain, installing a 2" stand pipe for stackable laundry.

[Hammerlane]

In the new drawing, is that a washing machine standpipe you have to the right of the sink on the first floor..

[Theory]

That's correct. I was hoping if I used the appropriate fittings and vents I could use a 2" standpipe drain tied in with the lav sink. If this is a problem I will plumb a 2" drain all the way to the 3" stack for the washer and a 1.5" drain for the lav sink...

[Hammerlane]

There was a thread similar to yours a few weeks ago where someone wanted to drain both sink and washer standpipe on same branch drain. The washer flowing past the sink drain is NOT the ideal configuration. I saved the persons finished configuration where he remedied and tied the standpipe and sink into the stack at different heights.

[Theory]

So with the distance, I can basically copy the above except adding an additional vent for the sink. (I'll use a 2" drain for washer, a separate 1.5" drain for the lav sink, each with their own vents that tie into each other with the toilet as shown in the drawing)

Also, just to confirm, a 2" vent is REQUIRED for a toilet?

[Terry]

Also, just to confirm, a 2" vent is REQUIRED for a toilet?

A 2" would be required within 72" with UPC plumbing code.
I don't know what the Ontario code is.

[Theory]

A 2" would be required within 72" with UPC plumbing code.
I don't know what the Ontario code is.

Hi Terry, a 2" vent for the toilet is required when the vent is longer than 72" the 3" according to UPC? Just want to clarify!

I should search some more and find out about max. vent lengths for my plan...

[hj]

The confusing part is that the left hand drawing shows the horizontal drain ABOVE the floor, but the right hand one has it BELOW the floor. Usually, when a main drain is above the floor it is because the main SEWER is NOT low enough for it to be under the floor. Or do you have enough headroom to raise the entire basement floor that much? IF so, or if you are breaking the floor to install the drainage, you drawing is MUCH too complex, (i.e., there are much easier ways to do it).

[Theory]

The right hand drawing is an accurate representation of how the main sewer drain is, 3" horizontal, 90 up through the floor with a cleanout, coninuing up the the main floor bath. I should have fixed the left hand drawing to show this better instead of just pointing the arrow.

I was planning on breaking the concrete to install the basement toilet drain/vent, however the horizontal drain for the lav sink and the separate drain for the washer stand pipe will be routed through the new walls draining into the main 3".

I will attempt a cleaner drawing, this drawing was mostly an attempt to see if I had the draining and venting done properly, but I can see it would be easier to get advice if I clarify the drawing showing horizontal/vertical better and lengths.

It was a first try!

[Theory]

Trying to use some 3D software this is pretty close to what my existing plumbing situation is. I did not included the existing laundry because I already know it's very wrong and it's a little complicated to draw.


I'm currently attempting to add the new plumbing setup I've sketched above.

[cacher_chick]

Your new drawing shows no fixture vents. The lav appears that it may be be too far from the stack to run it without a re-vent.

Here, you can wet vent a WC, but not the laundry. (if that is what i'm looking at.)

[Terry]

I don't think a laundry or washer can be wet vented anywhere.
In some codes, they require a 3" on the vertical waste for a washer after the vent.

[Tom Sawyer]

Yep the IPC now requires the laundry to dump into a 3" or larger stack and you can not wet vent laundry trays or washing machine stand pipes.