I have a leak where my drain pipe goes into floorslab. Only leaks when washer is in spin cycle. Not a very big leak but continuous. Would like to seal leak. Any suggestions?

PVC pipe?

Is your set up like this one? (see image) When the leak occurs take a folded piece toilet paper and starting at the top of the stand pipe wipe the pipe down past the trap. Any moisture on them paper? Let me know, To,