Waste Pipes Grading

7.4.8.1. (1):

"Every drainage pipe that has a size of 3" or less, and every fixture drain shall have a downward slope in the direction of flow of at least 1:50."


There are two main methods which can be used for grading pipes:


  1. 9-inch level

A straight piece of wood 12 inches long with a 1/4 inch strip of wood attached to one end can be used to set the 9-inch level on. A correct level reading will indicate that the waist pipe or drain has grade of 1:50 (1/4 inch to one foot).


  1. Adjustable Grade Level

This type of level is especially designed for grading waste pipes. It has an adjustable level which can be moved to the required grade and then locked in place.



  1. It can be also suggested to use surveyor's level to grade waste pipes and drains.



Calculations on Grading Waste Pipes and Drains

For 3" waste pipes and drains

grade = 1/4 ( Imperial Measurement Units)

or

grade = 1/50 (Metric System)