I have to run 4" drain pipe for the washer that is on the second floor, but, the building being old and all, I wouldn't want to rip the floors, instead, I was thinking of running the drain on the outside of the house and then go back in at the basement level. It would be preferable as the pipe would be hidden with other exterior pipes and would not look ugly or out of place. This is for state of CT, so to prevent winter freezing, I was told to go with 4" PVC instead of the 3" recommended by washer manual. Any suggestions? Drilling through the floor to run the pipe on the inside is not possible, so, what options do I have?