New built ranch with full basement, septic tank, 4" pipe to septic thru side wall and 4" pipe out back wall for grey water. only thing to septic is 3 toilets and kitchen sink, everything else going to grey water pipe. the house is 63' long with one toilet on far end up against back wall,12.5" rough in from plate. the 4" to septic runs in parallel to back wall. so I'm running a 3" pic schd 40 from far toilet all the way across back wall . there are 3 basement windows across the back wall also i don't want to block them by the 3" pipe. I have plenty of altitude as the 4"septic out pipe is 48" down from the bottom of the floor joists. The joists run perpendicular to the 63' back wall. I thought of running the 3" from far toilet along back wall but then it would be crossing the basement windows which doesn't make sense. From the toilet to the septic out pipe is about 57'. using 1/8" drop per foot thats 7.125".
QUESTIONS ARE:
IS 1/8" drop /foot and good slope for 3" pipe? Ive read both 1/8" and 1/4".
Would it be better to go from toilet flange with a 4" to 3" elbow, then run a section of 3" so it would be perpendicular to the back wall so the long 3" run is maybe 3-4' off the back wall then use a long turn elbow and then the long run parallel to the back wall. There is a kitchen sink I will bu running into the long run an an additional toilet down stream farther closer to the opposite end wall where the 4" septic out pipe is.
Sorry this is so long winded. Im sure a sketch would be better I'll try to attach one also.
Thanks a bunch I really appreciate any help.
View attachment house plans.pdf
QUESTIONS ARE:
IS 1/8" drop /foot and good slope for 3" pipe? Ive read both 1/8" and 1/4".
Would it be better to go from toilet flange with a 4" to 3" elbow, then run a section of 3" so it would be perpendicular to the back wall so the long 3" run is maybe 3-4' off the back wall then use a long turn elbow and then the long run parallel to the back wall. There is a kitchen sink I will bu running into the long run an an additional toilet down stream farther closer to the opposite end wall where the 4" septic out pipe is.
Sorry this is so long winded. Im sure a sketch would be better I'll try to attach one also.
Thanks a bunch I really appreciate any help.
View attachment house plans.pdf
