It is common for your plumber to use the word “back pitched sewer” but what does this actually mean? First it is most important to understand what it means to have pitch on your sewer line. The term pitch is the difference in elevation of your sewer line connection at the city sewer and your home.
To obtain proper pitch your house trap needs to be higher then the point where you sewer line connects to the city sewer, the sewage must run on gravity and needs proper pitch in order to flow down towards the sewer. A good rule of thumb to go by is that the sewer should have a 1/4″ of pitch per foot. For example, if your sewer line running from the house to the street includes a total of 20 linear feet then the sewer line should have a total of 5″ of pitch.
If there are any obstructions that do not allow for sufficient flow or if the elevations in-between the house and city sewer are not great enough you may have to entertain an alternative method.
One method includes raising all of the plumbing on the inside of your home which can serve as a large job pending the details of your internal plumbing. Another option is to install an ejector pump inside the home which would force the sewage upward towards the sewer line exiting your home. When possible we suggest to avoid relying on mechanics for sewage flow as it is always best to use gravity. Unfortunately in some cases you may not have a choice.
There are many other variables to consider when measuring for proper pitch, it is important to consult with a NYC licensed master plumber and discuss your issue as well as any the suggested resolution.