Hello all. Thanks for any help with this in advance!

I would like to retro-fit a washing machine in my ground floor condo.
My plan is to install a 2" stand-pipe and p-trap then run my 2" pipe 8' long, then turn 90 degrees then another 6' to a 2" combo stack that serves my lav and my upstairs neighbor's lav. I was planning on sloping 1/4" per foot, and connecting ~8" above the finish floor, just under where my lav connects. I'm concerned that the 14' run is too long or is it ok since I will have an air gap at the standpipe? I plan on buying a front loading washer or laundry center. I am aware that 2004 Florida plumbing code requires 3" for the stack at washers. I will not be pulling a permit...

Also, if the distance is OK, would I need a clean-out at that 90 degree turn?

TIA!

Well first off I would eliminate the 90 with a long sweep or two 45s. Next you can not use the washer stand pipe as a vent. It's on the wrong side of the trap for that. The job will have to be vented ,permit or not. I realize you're not pulling a permit or will not have it inspected but in order to not have a bunch of clogs and blockages it would pay you to stick close to code.
Code calls for a vent within 5 feet of the trap for a 2" drain line. The good news is that you can install a AAV,(Air Admitance Valve) downstream next to the trap and skate on running a vent to the roof. A little tip since you will have a unusually long horizontal drain line. Tie a sock or a lint catcher over the end of the washer discharge hose. You'll thank me for that advice later. Good luck, Tom

Thanks SpeedBall!
I was planning on using a sock or nylon. Attached is the solution based on how I understood your post. I should have no problem with a long sweep or two 45s.

How can I adequately support the cast iron stack while I rotozip out for my splice? I'd hate to assume that it's supported fully at the floor-ceiling above...

That other trap! Is it a floor drain? The diagram looks OK to me with the possible exception of that unvented trap. When I have to cut into a cast iron stack that I think may fall I use a raiser clamp,(see image) and two bumper jacks. Purchase a raiser clamp in the pipe size the stack is and Buy 2 NO-Hub Bands,(see image). Now rent a set of Ratchet Cutters from your local Rent-A-Center and mark out the edge of the fitting you wish to cut in. Now go back and increrase each of your marks by 1/8". This will allow for the neoprene gaskets in the bands. Place the raiser clamp above the top cut and bumper jacks on either side of the clamp. Now take up a strain with the jacks. Careful! There's a lot weight on that clamp make sure the jacks are in steady and won't slip out. Make the top cut first and then the bottom one. Now slip the metal band over the bottom pipe,now the gasket and roll it back. Do the same up top and slip the fitting in place and snap up the gaskets. Tighten the metal bands and you're home free. Best of luck, Tom

It's the lavatory. Actually it's 2 lavatories on a 1 1/4" line. Do you think they'll be fine, or will they need an AAV too?

Home depot didn't have the pipe clamp, doubt they will have the AAV, guess I'll have to drive around to find these and to find the cutter. That would be a lot better than roto-disc!

Thanks for your help!

"It's the lavatory. Actually it's 2 lavatories on a 1 1/4" line. Do you think
They'll be fine, or will they need an AAV too?"

Every fixture that has a trap MUST be vented.
Pipe clamps may be found at most plumbing shops.
Good luck, Tom