Roger Chaisson and two teens he knew had been smoking pot and wandering around the uptown, before breaking into the building at 127 Charlotte Street beside Trinity Anglican Church but left when they saw police cars outside only to return a short time later.
They began lighting pieces of paper and cardboard which set a wall on fire and spread.
Chaisson told police they tried to put it out but to no avail and then ran from the building.
Chaisson also pleaded guilty to damaging the lock on his jail cell door and violating a previous probation order. The court was told he has grade 9 education and has been drifting through life with no direction wanting only to take drugs.
Another of the accused, 19 year old Samuel Nolan has been declared unfit to stand trial.
