I am about to remodel my bathroom which is very small. The biggest problem I have is the concrete slab is not level and because of this over the years we have had several tolets broken. The only way to level it is to basically raise the toilet a few inches so we can have a level place for the tolit to sit. I know we will need to extend the sewedge pipe up and have a plumber set up for that what I need is how do I make the form and how tall should it be? How do I make the form and does it need to be reinforced with something?