adding a bathroom above garage, need to know if the number of bends on the drainage pipe which take use to the soil stack 30 ft away matter? as for right now how i am figuring is from the toilet have a 4" pipe go 2 ft then have a long 90 then 4' ft horz then another long 90 to 8' vert then another long 90 to 25' horz then another long 90 to the soil stack. is this alright as long as i stay at 1/4 per foot pitch? Do i have to worry about all the 90, can i use regular 90s . Thanks
usually when you are going from horizontal pipe to vertical pipe a regular 90' fitting may be used. When going from vertical to horizontal a long sweep 90' may be used. if exceeding 75 ft in pipe a cleanout should be thrown off before the 75 ft is exceeded. you can use the removeable toilet as a cleanout point.
Before you start buying material for your project check to be sure the stack is 4". Most residential stacks are 3" and you can not transition into 3" from 4". 3" is easier to work with and would be just fine for your project. If you do have a 4" stack you could easily transition the 3" into 4".