While the fire was considered suspicious, Cpl. Lori Canning said charges are not anticipated because a cause could not be determined.
A man, believed to be the owner of the building, was helped by neighbours before being taken to hospital and treated for smoke inhalation.
The shed was destroyed, along with a car inside and a pickup truck outside the burned structure. Losses were estimated to be around $40,000.
In addition to the Bay St. George RCMP, the Kippens Volunteer Fire Department and the Stephenville Fire Department also responded to the blaze, reported at about 6:30 p.m.
The fire scene was guarded throughout the night and fire investigators carried out their work the following day.