Manholes with depth from lid to invert of the outlet from 1.8m up to 3.0m and with nominal internal diameter (NID) from 1200mm to 2100mm:
Type B1: Precast base with VC/RC connections;
Type B2: In-situ base with PE sewer connections
Refer drawings WW210 and WW211 and their Tables for riser diameters
Note: Larger diameter manholes shall be provided depending on the number and size of branches, change of direction and the need for adequate benching.