if your dish gets struck by lightning believe me, you wont be worrying about the house electrics, itll be a good builder youll be needing, ive got a pic somewhere from when i first started with sky and we went to a service call (before digital) for no signal after a storm, pulls up to half a house where the customer told us he had no signal cos his dish had melted just before his wall blew up after being struck.
what you could do then is using a small jubilee clip type thing connect a cable to the outer body of the f connector on the LNB (remember to make it water proof after though) and run a small cable from this to the LNB arm (if its metal). when it rains then this will also discharge any static in the cable (but your pic will be affected more in this way during electrical storms, which is why you now only find an earth point on dodgey twin LNBS used by sky lol)
what you could do then is using a small jubilee clip type thing connect a cable to the outer body of the f connector on the LNB (remember to make it water proof after though) and run a small cable from this to the LNB arm (if its metal). when it rains then this will also discharge any static in the cable (but your pic will be affected more in this way during electrical storms, which is why you now only find an earth point on dodgey twin LNBS used by sky lol)