Trying to replace an old tub with a new shower. It had a 1-1/2" drain, and there's still a portion of that left that can't be easily replaced with 2".
In the attached picture, the shower is going to be on the left, where the small osb board is. The 1-1/2" drain is on the right in front of the toilet drain. It goes under the floor another 2'-6" before it turns down to the basement.
My question is, if I put in as much 2" as possible and then reduce right by the existing, do you think I'll have problems with water backing up in the shower?
In the attached picture, the shower is going to be on the left, where the small osb board is. The 1-1/2" drain is on the right in front of the toilet drain. It goes under the floor another 2'-6" before it turns down to the basement.
My question is, if I put in as much 2" as possible and then reduce right by the existing, do you think I'll have problems with water backing up in the shower?