Planning & EstimatingQuestion 317 of 360
During planning, what is the main reason to record the invert elevation of the sewer point of connection before designing the underground drainage?
a.To pick the fixture color
b.To confirm there is enough fall from the building's lowest fixture to the connection so gravity drainage will work
c.To size the electrical service
d.To choose the paint
Explanation
The invert elevation is the inside-bottom level of the pipe at the connection; comparing it to the building's lowest fixture confirms there is adequate fall for gravity drainage at the required slope. If the fall is insufficient, the plan may need a sewage ejector or a redesign. Verifying invert and slope up front prevents a system that cannot drain by gravity.
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