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?
In my experience a 2" drain line, 2" P-trap and 2" stand pipe coming up off the trap of at least 18" high has been the code for most areas for as long as I can remember. I would suggest that they hire a licensed master plumber to come down, look at the job and find the most cost effective solution for that particular job since there is no standard for each house that needs the plumbing to be upgraded.
Ed Del Grande is a three-time Master Plumber, GBCI LEED green associate, and contractor. He was born and raised in a family-owned plumbing business. He holds three current Master licenses in pipefitting, fire protection, and plumbing.