Quick Answer: Calgary commercial roof inspections should happen twice yearly (spring and fall) plus after every hail event with stones 25 mm or larger. A standard inspection costs $400 to $1,500 for buildings under 30,000 square feet and $1,500 to $4,500 for larger properties. Inspectors check membrane condition, drainage and ponding, penetrations, flashings, perimeter details, and substrate moisture. Documented inspections protect manufacturer warranties, support insurance c
