Recently I started a thread to get advice on how to move a flange for a toilet so that I can wind up with a 12" rough-in when I'm done. It's problematic since I can't really work with the ABS under the floor. It wasn't done properly and has the drain for the tub, the sink and the toilet all going into the same toilet drain. See photos below. To do it correctly would cost around $5K, according to a quote we got from a plumber recently.
To summarize from my previous thread I removed three layers of linoleum, two layers of fir planking and am now down to the bare joists. I cut away the flared portion of the flange and as you can see the hubs for both the ABS align with the hub of the offset flange. Meaning, they are both four inches in diameter. Also, now that so many layers of flooring has been removed I am wondering if I can shave off a bit of the hub from both the ABS drain pipe in the floor along with removing part of the hub from the offset flange to help bring it down lower. The hubs on both measure 1.5" in length. If I can remove an inch off of each hub to eliminate two inches and be left with just one inch to work with this would help a lot.
I thought I could buy some ABS piping that could fit inside both the flange hub and ABS hub in the floor. It would basically be a one inch ring connecting both hubs from the inside.
Once I put my 3/4" plywood over the joists, cement sheet rock and possibly a leveling compound followed by 1" hexagon porcelain tile I am confident that I can get the metal ring of the offset flange to sit flush against the new final height of the floor.
But I am wondering if my idea is bad one or if anyone can suggest better ideas. I really want to use the offset flange to not only give me about an extra inch from the back wall but also want to place it diagonally to allow an extra inch away from the side wall. It's a bit too close to the side wall. This is a 2" offset flange, by the way.
I've also included a very bad drawing to help provide a visual as far as getting my idea across without any confusion.
A summary with pics:
After sawing off the flared portion of the flange I am left with this: I am going to attempt to carefully grind away the rest of the flange that is bonded on the inside of the ABS in the floor to be able to re-bond the new ABS "ring" I will cut to size to connect the new offset flange in place.
Another angle where you can see all the the other ABS drain lines that connect to the toilet drain line: ^ This is why I simply can't just extend the horizontal portion of the ABS under the floor to give me a 12" rough-in. I' have to redo all the drain pipes that connect to one drain. It would be a real pain.
After sawing away the old flared portion of the flange I can see that only about a half inch of ABS from the old flange made a permanent bond with the ABS drain pipe in the floor. So this is why I am wondering if I can make the hubs a half inch in length and create a "ring" with ABS to fit inside each one to make this work.
Hope to hear back and get some input, thanks!