: I LIVE IN CANADA AND WOULD LIKE TO KNOW HOW FARE FROM THE WALL I MUST STAY WITH THE TOILET DRAIN Depends—-Finished wall? or rough (open studs)? Finish wall-12-1/2 approx. Rough – 1/2 drywall – 13-1/2 approx. This is if you have a 12 rough-in toilet. If you have a 10 or 14 toilet, adjust accordingly.