Spiridian Micallef from Sully Road in Penarth was ordered to pay a fine of £4,664 as well as £200 in costs and a victim surcharge of £100.
Councillor Lynda Thorne, Cabinet Member for Housing and Communities stated;
"The majority of private sector landlords keep their properties to a high rentable standard and these properties play an important role in Cardiff’s housing stock.
The small number of landlords that think that they can provide substandard accommodation which falls below the required standards, need to think again, as we will follow up complaints made and we will precede these matters through the courts.
There is no excuse to rent a property in this condition. It isn’t acceptable and I am pleased that the fine imposed by the court reflects the severity of this case."
A Cardiff landlord has been fined £4,000 after admitting renting five rooms to students which inspectors found had "dangerous failings".