Despite bad weather conditions and inaccessibility, fast-acting volunteers have successfully contained a bushfire to the west of Joadja.

Already engulfing more than 1500 hectares, the Joadja blaze rates as one of the State's largest fires yet volunteer efforts have ensured the fire threat to people and property remains low.

Incident controller David Phillips said by yesterday afternoon, fire control hoped to break the back of the fire giving volunteers the chance to move from a containment strategy to a more aggressive fire fighting program.

"Over the weekend we had about 250 people in the field working to put in close to 45 kilometres of containment lines," Mr Phillips said.

"Our biggest problem so far is the constant changing winds which have impeded much of our back-burning work."

Assisted by three helicopters, Rural Fire Service crews from the Wollondilly and South Coast were aided by easing weather conditions.

Mr Phillips said he was confident the blaze would soon be under control.