Washing machine waste line


I am building a laundry room within my basement. The plumbing was roughed-in the floor by the builders (toilet, shower and sink). Using the existing 2" sink drain, I put a 2" in T fitting for a washer drain and a 1.5" T for a bathroom sink and laundry room sink; there is also a 1.5" vent above.

The 2" washer drain is at 1/4" slope, passing through 5’ of wall and then making a 90* turn and running another 5’. I then have a P trap with a 20" standpipe.

I can not find anywhere in the Virginia code on the max length of the P trap arm/waste line, only says 1/4" slope for 2" or smaller line. Is a 10’ run a no-go period, would placing a vent half way through into - straight up and into the existing vent be good, install a AAV be good… Or good as is?

Another question: hot always on left… When running my water line parallel with eachother, then T and continue going across then 90*, and also going down at the T. When going down, hot ends up on the right hand side. Will this pass inspection as long as I correct this with the water lines into the valve faucet (cross braided water lines)

You might want to hire a plumber. Something don’t look right with your layout. The dryer box should be down at floor level, bit I see it would conflict with that plumbing so something might have to be switched around. You are limited to a distance to the vent also with the drain for the washer.
You might get a response from a plumber here on the board to help you out.

the dryer vent needs to be at its height for a stack able front load. Dryer is on top

per code, I can not find anything on max run, thats what i am trying to figure out. Code only says to vent every 8 feet for 2" pipe

Got ya. As far as the vent goes you should check with your AHJ for where you are.

Thank you sir, I finally got a hold of the inspector and it looks like the whole project is a no-go. No items are to be added to the bathroom rough-in. Due to it being a wet vent, only a sink, shower and toilet can tap into the drain. Alternative is to rip out the concrete, cap off the lines to disable future use of the builders rough-in. Also, per Virginia code, my drain line can be any length it wants to be, just needs to be vented every 8 feet.

You need to throw an inch and a half revent in after you pick up that P-trap you’re running a heck of a long distance without a vent. You have a short sweep fitting as a horizontal to horizontal transition that is illegal. Hot should be roughed in on the left on both sides. Keep the inlet of your washer box at 42 inches and the revent should be 6 inches higher. That test tee in the vent is weird. Plumbing is easy right?



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That works much better. Turn your tee 180° so that the sweep of the vent goes with the flow of the drain.

I believe Virginia just follows IPC 2015. Yes that looks fine make sure you run at least an inch and a half vent to the laundry box. It looks like you don’t have a shower you have a tub roughed in the concrete. Check with your plumbing inspector and make sure you can dump all those sinks into that one drain I believe that is your vent for your water closet and tub.

the rough in was for 1 sink, i changed it to a T for to sink rather than one (sink on each side of the wall), if allowed. How would you add a vent in the laundry room?

I would draw out a neat isometric drawing and submit it to your plumbing inspector. Draw out all of the vents and drains along with the size of pipe. If you’re not familiar with drawing an isometric it’s pretty simple there should be lots of information available online. Just remember horizontal drains on your isometric are 30°.

The vent for the laundry tub can either be ran in a small soffit that you will frame or drill through those floor joists properly. I hope you plan on replacing those studs that you drilled out.

for a 10 foot run, I have a vent in the middle. is that not enough for a vent on that drain?

i do plan to replace the studs.

That should be fine

can 2 sinks run into the wet vent?

I’m going to say no because I don’t see a separate vent for that tub. Again contact your plumbing inspector. Make a nice isometric neat drawing and he will edit it for you.

Thank you for all of your help. Ill send this off to them.