Police and fire investigators are set to probe how the fire started once the two-storey building on Green Street has been made safe.
Part of the main road in the town, the A689 westbound, remains closed and gas and electricity supplies nearby were shut off as a result.
Initially two engines from Stranton with the incident command unit along with appliances from Headland, Billingham and Stockton stations were dispatched.
A spokesman for Cleveland Fire Brigade said at 3.54am that firefighters focused two hose jets on the snooker centre’s roof void. The emergency services had scaled down their presence by 7.45am this morning.
“Stockton Street remains closed today while a structural engineer examines the damage to the building, which is thought to now be structurally unsafe,” said a spokeswoman for Cleveland Police.
"Members of the public are being asked to avoid the area if possible, however cordons do remain in place for public safety reasons."
She added: "Police and fire officers will begin an investigation into how the fire started once it’s been deemed safe to do so. The fire is currently being treated as unexplained."
Anyone with information is asked to contact police on the non-emergency 101 number.