A large number of firefighters remain on the ground working to slow the spread of the fire, which continues to burn in a southeasterly direction towards Barden Ridge.
RFS spokesman Greg Allan said some properties had not escaped unscathed.
"We have had reports of impact on properties in west Menai and Barden Ridge but our crews at the moment are solely focused on fighting the fire," he told AAP.
Residents in the suburbs of Voyager Point, Pleasure Point, Sandy Point and Illawong, Menai and Bangor were warned of the danger of ember attacks as many scrambled with hoses and buckets to protect their houses.
Daniel Borg, who lives on Hall Drive in Menai alongside bushland, admitted it was concerning to see how close the flames came.
"It was pretty scary," he told AAP when finally opening a beer, thankful his house came with sprinklers on the roof.
NSW Police announced a task force had been set up to investigate whether the fire, which began in the vicinity of Leacocks Reserve in Casula, was deliberately lit.
Conditions are expected to aid the firefighting effort today, with winds about half the strength they were yesterday.
The temperature may remain a cause for concern, according to the RFS Deputy Commissioner Rob Rogers.
"Still quite a difficult day ahead," he told the Nine Network. "I think we've got a long way to go before we're out of the woods."
Residents in Voyager Point, Pleasure Point, Sandy Point, Alfords Point, Barden Ridge, Illawong, Menai and Bangor were told to be prepared to activate their bushfire survival plans should conditions change.
Heathcote Road remains closed between Macarthur Drive and New Illawarra Road while Old Illawarra Road at Barden Ridge has reopened.
- AAP
