I would like to put my washer and dryer on the second floor, almost directly above the current location.

I plan to install a laundry box with a 2" standpipe approx 35" high and use a p-trap.

Under the washer, I will install a pan and drain it to the outside of the house.

On the second floor, I have access to the vent pipe. Can I tee into the vent pipe at floor level for the drain, then tee up off the vertical drain line back into the existing vent line?
Will this work?

Is there anything else I should worry about?

TIA,
Colin

If you are moving w/d right above, chances are that the dedicated washer vent pipe is going directly up. Cap off drain inlet at the old location. Go upstairs, cut vent above the floor, install 2x2 saninary T, install P trap and 36" of 2" stand pipe.

Now, this was the best scenario. You have to inspect the existing washer vent you want to connect into. Make sure it is a straight run. If it has any bends in it, they should be long 90's or 45's. Also, make sure there isn't other vent connected to it below the point of upstairs' drain connection.

You may have 1 1/2" washer vent. You will need 2" existing vent if you want to use it for upstairs' drain. You can continue with 1 1/2" vent up from the new 2" the point of drain inlet upstairs.

Hi Milo,
The vent line is not directly above the existing drain. It comes up through the wall then tee's out to my master bath sink group, then ells out 24" horizontally then ells vertically thru the roof. all the ell look like long ells. The bath group appears to have it's own vent in another part of the roof.

Do I need to run a vent line back into the existing stack for the washer?

all the piping is 2".

What worries me is that vent T for your MB sink group. Here is why: We usually install vent fittings pointing upwards, towards the roof. That means, anything flowing downwards will have tendency to split the flow and enter other vent groups via T's and Y connections.

So, in your case: if you run your upstairs washer through that pipe, water will get to your T for your sinks and will enter sink vents as well. Now, if that sink vent T is installed vertically that you may get away with it. If it is installed horizontally, you will probably have to rework it, meaning, you will have to make the drain connection below this T.

Yes, you need to install 2" vent for your washer. You can reconnect with existing vents someplace in the attic.

Hi Milo,
After careful examination, my initial observations were a little off.

It looks like my existing laundry standpipe and laundry sink are tee'd together (2") and then the vent goes upstairs as 1 1/2" through the roof.
The MB group is on its own.

I guess my next move is to cut the drywall and change the 1 1/2" vent to 2".
I understand you as saying I can just convert from where my new laundry standpipe connects down to the original tee location to 2" and leave the vent above as 1 1/2".

Thanks in advance for your advice.

I understand you as saying I can just convert from where my new laundry standpipe connects down to the original tee location to 2" and leave the vent above as 1 1/2".
Yes, That's what he was saying. You may keep the downstairs sanatary tee and simply cap off the branch Good luck, Tom

Thanks to Milo and Speedball1.

I cut open the wall, replaced the 1 1/2" vent line with 2" pvc.

Just working on getting the water supply lines now. Should go pretty easy with pex. I have grown to love that stuff, especially when fishing up through small openings.