Six high rise blocks of flats have failed fire safety standards, despite passing initial tests in the wake of the Grenfell tragedy.
Lydstep Flats, Llandaff North (3 blocks), Loudoun and Nelson House, Butetown and Channel View, Grangetown, did not meet safety regulations.
After the Grenfell Tower fire in June of last year, where more than 70 people were killed and 70 more injured, the Welsh Government carried out inspections across all high rise buildings in Wales.
Initial tests on the six buildings showed no presence of Aluminium Composite Materials (ACM) - the flammable material used in Grenfell.
Testing of ACM was all that was required by Government.
However, Cardiff Council carried out additional tests after it was recommended by external consultants to establish whether the cladding, which was installed in the 1990's, would meet current regulations.
Now, nine months on, results show, although they do not contain the same cladding used in Grenfell, the veneered, fibrous-hardwood, rainscreen panels used in the buildings do not meet current combustibility standards.
It is likely that the cladding will need to be removed, say Cardiff Council:
Letters have been handed out to residents informing of the latest developments.