hi again , i was round a friends last night who showed me a renderd wall which he had put finish over , he has now got a huge bubble on his wall.
as i am shortly about to go on a plastering course he asked my advice which i couldn't give .
in this instance (should i ever come across it again in my time) should you do a repair job on just the bubble by knocking it off and patching it up, or re- do the whole wall . and (secondly) what an earth could have caused this , a dirty wall , a bad bag of finish ,
please help as i need all the information i can to get a head start when i go to collage .