Modelling a duct bank but can't get strip components and end conditions to produce the backfill mesh

Hi,

I have followed the Bentley Video on modelling duct banks to do my own (video here: https://www.youtube.com/watch?v=5Y3a54S-CVM) but I cannot get the strip components to produce the backfill as per the video...end conditions work fine but how has this Bentley guy got the half green mesh on his template?

mine looks like this (sceenshot is annotated):

Thanks,

Mark