A Christchurch truck has taken an unscheduled detour early this morning, ploughing through an intersection, and drainage ditch before coming to rest in the side of a building.

The truck left behind holes in the road, and a mass of broken branches from surrounding trees, while a piece of the truck's cab left at the scene suggests it was operated by Mainfreight.

The driver escaped uninjured but left a large hole in the side of Snell Packaging and Safety.

Police say there's no obvious cause of the accident that happened just before 1.30am this morning in the industrial section of Waterloo Road.