Minimum slope 1/8 per foot…solids move best at 1/4 per foot… do not exceed 1/2 per foot or the liquids will run ahead of the solids, and they will clog up your pipe. Check your local code regarding the vent…Good luck!: adding toilet and shower to basement. using 3 plastic pipe connecting to existing 3 iron pipe. need to know how much slope per foot i should have. maximum distance about 8.
