A tenant sent the landlord a worried text on Saturday and he responded yesterday.
Props were put up against the flat, at 116 Union St East, as the landlord and his son worked to secure the balcony, which had "dropped a couple of centimetres''.
The landlord's son, tradesman Michael Kinraid, said the work was precautionary and they were making sure it was safe.
"Obviously after Friday ... it's better to be safe than sorry.''
Mr Kinraid was putting in bigger bolts and ensuring the balcony was well supported.
"I've seen them completely full [with people] before [but] we've never really had any problems with them. All our decks are just on top of each other so there's not really any risk of them falling down. We'll just go round and check them all.''
His father owned several flats in Dunedin, he said.
He believed it was not the landlord's fault that the Castle St balcony collapsed and said the students should have been aware it would not hold up.
"You couldn't fit one more person on the deck.''
Otago Property Investors' Association president Wendy Bowman said she had not heard of landlords specifically checking balconies but said the incident would be on the agenda of a "north end'' meeting of landlords.
"We love our tenants, we love our students, we don't want them to be hurt,'' she said.
"Sometimes, there's an accident and we sort of have to work out what we want changed to make things safer. When an inspection takes place, that's when they should be looking for these things.''
Ms Bowman said the more local organisations could get together and talk, the better off both tenants and landlords would be.
"The more that the agencies and the DCC, the university, landlords and other agencies get together, the more we can make it safe for everyone.''
