Hello group

We live on the 2nd floor of a 3 floor condo building. The washing machine
is drained by the hose being stuck into a pipe that diagonally sticks out of
the wall about 4-6 inches above the top of the machine. The problem is that
no matter what we try, the water backs up in that pipe and comes pouring out
the top when the machine drains. We've tried clamping sections of the hose
to try and slow the volume of water draining but we almost need to clamp it
off completely otherwise it still overflows. We've tried using lesser and
lesser amounts of detergent thinking maybe it's the suds that are building
up in the pipes and backing the water up but it makes no difference. We've
had several machines in here over the years and the problem happens with
each of them. Every couple of months we're able to compress and tape part
of the machine drain hose and get it set just right so it drains without
overflowing. However it keeps coming back.

Anybody have any ideas that don't involve ripping down walls floors and
ceilings or paying a plumber $500 to dig through the system?