Hi, I'm adding a shower and was goint to use the rolled rubber they sell at
home depot, but someone mention I need a HOT MOP to seal the shower
otherwise it would leak.

I called a plumber and he said he never used the hot mop, only the rubber.

Do I need or not the HOT MOP and if I do, how much does it cost to get
someone to pour it.

I'm in orange county, CA.

Thanks,

Ruben