Washer Box Install

[Greg12]

I drew a quick schematic of my current main floor laundry plumbing situation (washer currently drains into a laundry sink) and a proposed situation to install a washer box a couple feet over.

In short, is the proposed routing acceptable?

Constraints: This wall is load bearing and is constructed with 2x4s. Also, the washer box needs to be placed in the wall void two 2x4s to the right of the current plumbing stack. Of course, I won’t be able to bore and run 2” plumbing through these two wall studs and attach the proposed standpipe to the current stack, so I figured routing new 2” plumbing directly into the basement and over to the current stack is a viable option while still meeting requirements for washer standpipe height, p-trap above floor, etc.

If this routing is acceptable, are there any other things to consider? I should be able to fit the p-trap and sanitary T between the two studs (it seems it will just meet code in this small space, with the 4” trap weir to stack measurement just being met, and running the 2” pipe above (reducing to 1.5” for venting) and below. Some other details/proposals are in the picture.



This is a visual of what I intend to achieve in the 2x4 wall cavity. I found it online and is just for reference.


I had a plumber come and quote installing a box, and as much as I believe he was worth every penny, the quote was outrageous. I’d rather keep the washer draining into the wash tub - haha. A second plumber came in a bit less costly, but he mentioned routing the 2” pvc in the wall through the studs. I didn’t entertain him for another second. At this point, I’ll gladly tackle the project myself, but want to make sure everything is done to code.

This is probably not important at the moment: I have also considered just installing the standpipe, plumbing for it, and washer box on the current wall instead of recessed in the wall, connecting it directly to the current stack. I’d still do some work to increase the stack in the wall and basement to 2” and reduce above to 1.5 for the current laundry sink. I intend to upgrade the laundry room and put counters over the front load washer, dryer, sink cabinet, cabinets, etc. Everything here would be hidden anyway. Shoot, after typing all of this, I’m now thinking about this option lol.

Thanks in advance! If there are any ideas, I’m all ears! Regardless of the best option, I want everything done right.

 

[CT18]

I believe Michigan code still says a washer stand pipe needs to discharge into a 3" stack. The laundry tub on the 2" is ok

 

[Greg12]

I believe Michigan code still says a washer stand pipe needs to discharge into a 3" stack. The laundry tub on the 2" is ok

Ahh, perfect. I missed that.

I could connect the 2” run to the next stack (3”) shown in the photo in the basement instead of the current stack. The 3” stack is about 9 feet away from the 1.5” laundry sink stack. The 3” stack is for a spare bathroom.

Would this work, and maintain the rest of the drawing?

Thanks for that information!

 

[MicEd69]

I had started typing that suggestion when you just replied. Yes, if you run your washer drain line over to the 3" stack and vent it as you show in your sketch, you will be just fine with your installation. And you do not need to change that existing 1 1/2" vent line to 2" in the basement.

 

[Greg12]

I had started typing that suggestion when you just replied. Yes, if you run your washer drain line over to the 3" stack and vent it as you show in your sketch, you will be just fine with your installation. And you do not need to change that existing 1 1/2" vent line to 2" in the basement

Awesome!

Here’s a new schematic.


Once in the basement, the 2” run will have to make a couple small turns. One to avoid the current 1.5” stack and then another to turn and connect to the 3”. Both 1.5” and 3” stacks are hidden in the same wall on the main level and are in line in the basement.

Thanks, all! Are there any other considerations? Concerns? I’ve read somewhere that some plumbers would not fit the trap and standpipe in the same cavity between two 2x4s. It seems fine (barely meeting minimums), but with things vented as shown, I can’t grasp why this would be avoided. Out of caution? This planning is contingent on this in-wall routing.

 

[MicEd69]

Note that you do have a minimum distance of 4" that is required between your P-trap weir and the vent connection. The sketch below is for the UPC, but that requirement is the same for IPC. Depending on where you are located, I think Michigan's code is based on the IPC. The IPC allows the standpipe to be a maximum of 42" instead of the 30" maximum shown the sketch below. The other minimums and maximum dimensions in the sketch are the same for both codes.

 

[MicEd69]

Oh, and your connection to the 3" stack should be done with a 3"x3"x2" reducing wye, not a reducing sanitary tee.

 

[turdchaser2000]

I believe Michigan code still says a washer stand pipe needs to discharge into a 3" stack. The laundry tub on the 2" is ok

In Michigan the 3” rule is for commercial, Residential can still connect to a 2” stack

 

[Greg12]

In Michigan the 3” rule is for commercial, Residential can still connect to a 2” stack

Thanks for all of the feedback, all!

I can connect to either, but connecting to the 2” stack would be ideal as this to-be 2” stack is directly below the first floor laundry room whereas the 3” stack is another 9 feet over.

If my initial proposed drawing is acceptable, this is what I’ll do!

Question about the wye: what’s the thought on connecting to the 3” with the wye. Would I do the same to connect to the 2” stack? Why not a sanitary T?

 

[turdchaser2000]

Thanks for all of the feedback, all!

I can connect to either, but connecting to the 2” stack would be ideal as this to-be 2” stack is directly below the first floor laundry room whereas the 3” stack is another 9 feet over.

If my initial proposed drawing is acceptable, this is what I’ll do!

Question about the wye: what’s the thought on connecting to the 3” with the wye. Would I do the same to connect to the 2” stack? Why not a sanitary T?

A San tee or wye would be acceptable

 

[MicEd69]

"IPC Section 406, Automatic Clothes Washers, 406.2, The trap and fixture drain for an automatic clothes washer standpipe shall be not less than 2 inches in diameter. The fixture drain for the standpipe serving an automatic clothes washer shall connect to a 3-inch or larger branch or stack."

As I said, I believe Michigan's plumbing code is based on the IPC code, and the above is for residential plumbing.

And the existing 1 1/2" vent line, that would be enlarged to 2", would become a wet vent which would also potentially cause issues and definitely not per the code cited above. Connecting into the existing 3" stack, a sanitary tee would be acceptable, but a wye would be better plumbing practice as it directs the rather high volume of flow from the washing machine down the stack MUCH better than a sanitary tee.

 

[Greg12]

"IPC Section 406, Automatic Clothes Washers, 406.2, The trap and fixture drain for an automatic clothes washer standpipe shall be not less than 2 inches in diameter. The fixture drain for the standpipe serving an automatic clothes washer shall connect to a 3-inch or larger branch or stack."

As I said, I believe Michigan's plumbing code is based on the IPC code, and the above is for residential plumbing.

And the existing 1 1/2" vent line, that would be enlarged to 2", would become a wet vent which would also potentially cause issues and definitely not per the code cited above. Connecting into the existing 3" stack, a sanitary tee would be acceptable, but a wye would be better plumbing practice as it directs the rather high volume of flow from the washing machine down the stack MUCH better than a sanitary tee.

Awesome.

Make 2” Standpipe, trap, and line dropping from first floor laundry into basement all 2” (code is everywhere on the internet and here, so I’ll follow the image on this post - also shared by you) and connect to 3” stack in basement.

For venting, should I alter the plan and keep the new 2” pipe routed into the attic instead of reducing to 1.5”? It sounds like I should connect the new 2” standpipe vent pipe to attic and route directly to the 3” stack in the attic, too, instead of reducing it to 1.5” and connecting to the existing 1.5” in the attic (which then connects to the 3” vent stack).

If this is the right way to do it, that’s what I’ll do. I’ve seen too many plumbing horror stories!

 

[turdchaser2000]

Awesome.

Make 2” Standpipe, trap, and line dropping from first floor laundry into basement all 2” (code is everywhere on the internet and here, so I’ll follow the image on this post - also shared by you) and connect to 3” stack in basement.

For venting, should I alter the plan and keep the new 2” pipe routed into the attic instead of reducing to 1.5”? It sounds like I should connect the new 2” standpipe vent pipe to attic and route directly to the 3” stack in the attic, too, instead of reducing it to 1.5” and connecting to the existing 1.5” in the attic (which then connects to the 3” vent stack).

If this is the right way to do it, that’s what I’ll do. I’ve seen too many plumbing horror stories!

As I said the 3” rule in Michigan is based on the IPc commercial Code. It is perfectly acceptable to connect in residential to a 2” stack. Michigan also has a residential code book that has a few differences from the commercial book. Also I agree the wye would better direct the flow from the machine however technically this would be a code violation as it creates what would be considered an s-trap which may promote siphoning of the trap.

 

[Twowaxhack]

Once it’s vented you can connect downstream at the 3” with a wye or tee. Either would be code approved.

It only needs a 1.5” vent. It’s not wet vented, it’s an individual vent.

Use a 2” trap arm and trap.

 

[MicEd69]

What Twowaxhack said!

 

[Greg12]

Once it’s vented you can connect downstream at the 3” with a wye or tee. Either would be code approved.

It only needs a 1.5” vent. It’s not wet vented, it’s an individual vent.

Use a 2” trap arm and trap.

Thanks, all!

Vent as shown in my diagram using 1.5” into the attic. Run the 2” plumbing from standpipe and trap into basement (shown in pics) and run horizontally (also 2”) and then connect to 3” stack with wye or tee.

 

[Twowaxhack]

Thanks, all!

Vent as shown in my diagram using 1.5” into the attic. Run the 2” plumbing from standpipe and trap into basement (shown in pics) and run horizontally (also 2”) and then connect to 3” stack with wye or tee.

Sounds good to me