A condominium fire that displaced hundreds of people in Langley, B.C. earlier this month was caused by "smoker's material," officials revealed Monday.

The blaze broke out the morning of Dec. 11 at Paddington Station complex, located near 56th Avenue and 201A Street. Dozens of firefighters spent around eight hours battling the flames, which moved from a fourth floor unit into the attic, eventually causing a number of ceilings to collapse.

A little over a week later, the City of Langley said investigators determined the fire started because of "improper disposal of smoker's material" on a balcony.

"Smoker's material needs to be disposed of in proper ashtrays. Potting soil often contains peat moss which is combustible," Fire Chief Rory Thompson said in a statement.

Officials said 18 balcony fires have been reported in the city over the last five years, half of which required firefighters' help to put out. All nine of those were caused by smoking, and usually by butting out cigarettes in planters.

It's possible the fire wouldn't have spread if the building had sprinklers on the balconies and in the attic, according to Chief Thompson, who advocates for such measures in all multi-story residential buildings.

Thompson also urged renters to buy tenant insurance, as building owner's insurance only covers the structure, not the contents of individual units.