I have a new washing machine that is connected to a 1 1/2in drain on my second floor. When the washer starts pumping the water out, the 1 1/2in drain cannot keep up with the speed of the water being drained. I have read that 1 1/2in used to be the standard for washing machines but now 2in is standard. As this is an older home, replacing the pipe is not an option without tearing out walls in my kitchen which is right below the laundry room. Is there another solution for this?