I know its legal, I know sky gods can pull it off BUT, the one that sets my teeth on edge is a right base join in a left hand circuit that is in use and is used pretty constantly by student pilots.
Its only legal if you have ATC and they clear it. If not, its a breach of Rule 12
Flight in the vicinity of an aerodrome
12 (1) Subject to paragraph (2), a flying machine, glider or airship flying in the vicinity of what
the commander of the aircraft knows, or ought reasonably to know, to be an
aerodrome shall:
(a) conform to the pattern of traffic formed by other aircraft intending to land at that
aerodrome or keep clear of the airspace in which the pattern is formed; and
(b) make all turns to the left unless ground signals otherwise indicate.
(2) Paragraph (1) shall not apply if the air traffic control unit at that aerodrome otherwise
authorises.
One of the problems is that the only published procedure for a standard overhead join depicts the aircraft approaching from the live side of the airfield. Exactly what the sequence of events should be if approaching from the dead side is undefined.
The live side is where the procedure begins, therefore you put yourself on the live side to commence the procedure. You can go around in the overhead in accordance with Rule 12 as many times as you like before commencing the procedure and whilst trying to fathom out the content of the signal square and work out where you are going to go. An "overhead join" commenced on the Dead side is actually a Crosswind Join because you are not complying with the Standard procedure and the place you join the circuit is on the Crosswind leg.