Can a Sewer Line Be Laid Below the Basement Floor Elevation?

Building Codes

• Before any work is done on your house drain system, the local municipal building codes should be consulted. You should also put a call in to your local sewage authority to ensure the proper permits are granted and procedures are followed. Improperly placing a sewer line can lead to big problems down the road, so care should be taken do it right the first time.

Slope

• An important factor to remember is the need for the sewer line to have a downward slope away from the home. A sewer line can be laid as low as you like as long as this slope is maintained. The slope must be 1/4 inch per foot of horizontal pipe: This means the pipe has to decrease in elevation by 1/4 inch for every foot there is between the house and the main sewer line. Failing to maintain this slope can lead to improper drainage and even sewage backup.

Backflow Prevention

• A sewer line that is laid beneath the basement floor should have a back-flow prevention device installed. These pieces of plumbing will prevent sewage from backing up into the basement and overflowing your drains. They will also ensure sewage is diverted to the clean-out access point, should a clog occur and your line needs to be opened.

Grinder Pump

• A grinder pump is used to transport sewage and waste water up to a drain that is higher than the output level. Such pumps are frequently employed in plumbing basement toilets and sinks when they lie beneath the level of the sewer line. If your household sewer line is lower than the municipal sewer line, a grinder pump may be necessary to pump sewage out of the household pipe and into the municipal sewer.