POLICE forensics have finished their assessment of the crime scene at St Carthage's Cathedral in Lismore, and firefighters are clearing out the rubbish from the sacristy.
A cherry picker is being used by the diocese to inspect the roof damage.
At noon the SES Lismore Unit arrived to place tarps the damaged roof ahead of the rain predicted over the weekend.
NSW Fire & Rescue Inspector Brad Harrison said firefighters did an excellent job extinguishing the fire so quickly.
Act Insp Fraser Hindry said crews also ensured they preserved the scene as much as possible to allow police to conduct a forensic examination of the scene.