Washer Machine Outlet Box Plumbing

Users who are viewing this thread

Andrewkay

New Member
Messages
4
Reaction score
0
Points
1
Location
California
Hello,

Looking to re-plumb my garage laundry setup and install a nice recessed washer outlet box and add a drain line for a utility sink. My house was build sometime in the 60's and so I noticed the existing drain and vent line is 1.5" copper, but apparently current code is for 2" PVC (for at least the drain portion). The drain line continues as copper under the crawlspace and leads quite a distance to the main cast iron drain going to the sewer. Would it be sufficient to plumb 2" PVC in the wall and then use a reducer to hook up to the existing copper line in the crawlspace or do I absolutely need to re-plumb the whole drain network underneath to all 2" PVC ?

Because of the odd stud spacing I have it looks like I would have to move the drain and vent line to accommodate for the in-wall 2" plumbing needed for the outlet box. In the SketchUp illustration I have attached, I utilized an air admittance valve, but I hear those may not be allowed in the Bay Area, California where I live. Is this true? I figure if I can't use the AAV, I could use a 45 elbow to connect to the vent further up the wall using a PVC to copper reducer coupling (currently the vent line is where that outlet box is in the 'ideal' layout I have illustrated).

As far as the utility sink drain, I'm told that those need to be about 18" off the ground, but my issue is the actual floor of the garage extends about 13.5" past the 2x4 bottom plate of the wall framing. Would I need to drop the whole plumbing setup closer to the ground to achieve that? I was worried the washer would encounter draining issues if the outlet box was positioned too close to the top of the washer machine (as pictured, the washer machine is on the floor of the garage for reference).

Thank you very much for your time!

laundry.jpg


This picture is ideally how I'd like the project to turn out. The outlet box is for PEX; im going to cut off the existing copper water supply lines and use sharkbite fittings to connect the copper to PEX.

IMG_1544.jpg


Here is what it looks like currently. The two water supply lines are sandwiching the drain and vent 1.5" copper line. This plumbing is in the largest stud space in the SketchUp picture above.

IMG_1540.jpg


This is under the crawlspace. Looks like a 45 elbow. I read that I would need a long sweep 90, is that correct?
 

Terry

The Plumbing Wizard
Staff member
Messages
29,942
Reaction score
3,458
Points
113
Location
Bothell, Washington
Website
terrylove.com
45's or long 90's are good for waste below the floor. A long 90 is basically two 45's put together.

I doubt that you can put a cross at the correct height for both the washer and the laundry tray.
Is this being inspected? If so you may need to run 2" for the waste portion and 1.5" for the vent. Inspectors are not fans of AAV's for washers, though they do work.

If you plan on using the existing 1.5" for the waste, the only place I can see bumping up to 2" would be above the washer trap for the standpipe.

I prefer to vent the washer and the laundry tray separately.

washer_rough_b.jpg
 

Andrewkay

New Member
Messages
4
Reaction score
0
Points
1
Location
California
Thank you for getting back to me so fast, Terry. I have a few follow-up questions:

(1) When you say, "the only place I can see bumping up to 2" would be above the washer trap for the standpipe", is this because that area receives most of the high pressure flow from the washer drain, and less so further down the plumbing chain? Or is it simply because the outlet box drain hole is 2"? I'm just worried if I don't retrofit everything to 2" I'll run into drain issues later down the line.

(2) Is it better to get an outlet box with built-in water hammer arrestors like the one you have pictured there? I seem to notice a lot of noise coming from the current washer water supply pipes.

(3) Is it appropriate to have bends in the vent piping? I mentioned in my original post that I may need to reposition the drain and vent as I have limited stud real estate to accommodate the new piping setup that I'm looking to do.

(4) It obviously sounds best to get the project inspected. What reasons would someone have to not get an inspection?

Thank you,
Andrew
 

Terry

The Plumbing Wizard
Staff member
Messages
29,942
Reaction score
3,458
Points
113
Location
Bothell, Washington
Website
terrylove.com
Washers used 1.5" drains in the 60's. Since I started plumbing in the 70's it's always been 2.0" for me. If I'm retrofitting to a box with existing 1.5" I like to at least increase the standpipe sizing so that there is some buffer there. I doubt that meets any code, but it's better than a 1.5" standpipe.

I always install boxes with the hammer arrestors. I think it's easier on the machine and the hoses.
 

Jeff H Young

In the Trades
Messages
8,753
Reaction score
2,164
Points
113
Location
92346
Thank you for getting back to me so fast, Terry. I have a few follow-up questions:

(1) When you say, "the only place I can see bumping up to 2" would be above the washer trap for the standpipe", is this because that area receives most of the high pressure flow from the washer drain, and less so further down the plumbing chain? Or is it simply because the outlet box drain hole is 2"? I'm just worried if I don't retrofit everything to 2" I'll run into drain issues later down the line.

(2) Is it better to get an outlet box with built-in water hammer arrestors like the one you have pictured there? I seem to notice a lot of noise coming from the current washer water supply pipes.

(3) Is it appropriate to have bends in the vent piping? I mentioned in my original post that I may need to reposition the drain and vent as I have limited stud real estate to accommodate the new piping setup that I'm looking to do.

(4) It obviously sounds best to get the project inspected. What reasons would someone have to not get an inspection?

Thank you,
Andrew

1 I think increasing stand pipe would be ok as terry suggested and My guess he said the only place he sees is because You cannot choke a drain line down you can drain a small pipe into a bigger one and not the opposite. (there may be an exception on the stand pipe) but remember it must be to code
2
either type is fine. but you must install
3 as many bends as it takes its just a vent dont knock yourself out . I would never install an AAV on a job if its under an hour or 2 to put a real vent
4 All the questions in your original post plus many more could be adressed by the inspector( failed inspection correction notice) You have to go through the trouble to get permit, pay MONEY, and Have some guy come out and perhaps not even look at anything or Ream you a new one for everything under the sun or even be wrong and tell you you need to change this or that. You can be delayed for days or who knows how long with this Covid BS waiting for inspection . If pulling a permit Inspector may/ SHOULD require you to update to a 2 inch waste all the way. but dought he will crawl under house.
All these reasons might make you choose to DIY and Do it HOw you want and not pull a permit but the Right Way is to pull a permit . The law is it requires a permit. Have I done jobs like this without a permit ? maybe Have I done many many jobs way bigger than this without a permit? maybe. My guess Is quality work done will cause less trouble than shoddy work whether permited or not. selling house later if you do a lot of crap work like a house flipper does you may have a problem by a sour home buyer especialy if prices go south . One thing about permits thats good is it creates more revenue for the tradesman but forces us to be on point with codes reducing short cuts but keeping costs up.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks