On 02/01/2019 22:52, RJH wrote:

It's more the 'client' - he's quite impatient and has a habit of looking
for fault when it isn't necessarily there. A sort of irritatingly
enquiring mind looking for shortcuts.

Set ground rules. If he doesn't obey them just don't go for a few weeks
til he rings up. Then warn him. Be as awkward as he is. Don't give him
an inch. It's the only way. I'm speaking from 45 years' experience
installing for private customers.

Bill