The City of Cape Town fire department's post-incident report into the blaze that ravaged Parliament has confirmed that the National Assembly sprinkler valve was not serviced since 2017 and was closed at the time of the fire.

The report also confirmed that the fire doors were latched open, which assisted in the spread of the fire.

"During my walk around of the affected areas I found that the National Assembly sprinkler valve was not serviced. [The] service date was in 2017 and this needs to be done every three years and the valve appeared to be closed.  If properly serviced, this valve should have been locked with a chain in an open position and a block plan would have been available showing [the] system layout. The lifts continued to operate, despite a "break glass" unit at one lift being activated," Station Commander JJ Williams said.

Public Works Minister Patricia De Lille told Parliament on Tuesday that the sprinkler system was "fully functional" by October 2021.

Williams added that the roof smoke activated at the National Assembly.

Divisional Commander Wayne Visser also stated in the report that the emergency staircases were poorly ventilated with minimal natural vents to the outside. No mechanical venting of the staircases was observed.

"It is unclear which apportion of the building was actually fitted out with sprinklers. The required layout block plan at the valve set was illegible," Visser added.

The report also raised concerns about wall panelling and décor materials that contributed to the fire.

The fire was contained after a two-day battle. It was initially declared under control on Monday but flared up again after it was fanned by strong winds.

Flames broke out in the Cape Town precinct shortly before dawn on Sunday and spread to the National Assembly, causing the roof to collapse and threatening artworks and artefacts in the building.

Cape Town Mayor Geordin Hill-Lewis said he received the post-incident report and added that it was handed over to Speaker of the National Assembly, Nosiviwe Mapisa-Nqakula

"The report is a useful insight into what firefighters saw on the ground. But this report does not substitute a full professional forensic investigation into the cause of the fire and whether any system failures exacerbated the spread," he said.