Convert toilet drain to 2" washer drain

[hydrostream]

Can i ues a new toilet flange upside down to make a 2"
washer drain? I will use a trap and maybe a indoor vent.
Thanks stream

 

[phishfood]

Is the pipe in the slab 4" PVC or ABS? If so, you could remove the current flange and glue a 3" coupling inside of it, then a bushing into that coupling.

But I would be very cautious about draining a washing machine into a pipe without knowing the venting arrangement of any nearby fixtures. When it drains a washing machine can cause traps of other fixtures to either siphon or bubble if the venting is not done correctly.

I wouldn't recommend bolting 2 toilet flanges together face to face. Longterm, that is asking for leaks.

 

[hydrostream]

That toilet drain goes out of the house and is connected with a Y
to the other main about 10 to 15' from the house. About 5' off
the house both 4" pipes have stacks that stick up from the ground
with turn downs on them like candy canes. Not sure but i think
the pipe at the toilet is cast iron.
stream