They were also dismantling the weapons.
"We're still searching" for more weapons, Constable Angela Butler told AFP.
Butler said investigators will soon search for more bombs in a two-by-three-meter (six-by-10-foot) cement bunker in the backyard about two meters beneath a stone patio that was stocked with food and water.
"Officers are in the most intensive area now," she said.
A suspect in a 1978 cold case murder who turned himself in to police on July 11 triggered the search of the house and the evacuation of 57 residents from 22 homes in the neighborhood.
The body of the murder victim, Michael Traynor, who would have been 60 years old this month, was discovered in October 1978 in bushes off a main rural roadway, one month after his disappearance.
Suspect Donald Feldhoff, 54, was scheduled to appear in court later Wednesday. He informed police about the stash of explosives, said Butler.
"There's no indication why the suspect amassed so many bomb materials," she said, adding: "It's now before the court."
His father, William Feldhoff, 75, has also been charged with accessory after the fact.
Since the pair's arrest last week, police have uncovered "lots of wiring around the house, and devices connected to the wiring that you could describe as booby traps," Butler said.
The Royal Canadian Mounted Police bomb squad was called in to help dispose of the explosives. Officers in heavy protective gear painstakingly removed materials from the house and robots detonated explosives behind stacks of sandbags.
Some of the bigger bombs were taken away in a "containment vessel" to be safely exploded elsewhere, Butler commented.
Two shotguns and three rifles, including a civilian model of an MP5 military submachine gun, were also seized from the house.