Calgary Roof Repair. A roof leak is due to when your roof fails to direct water or melting snow off your home or commercial property. Depending on the size, location and severity of the leak, you will likely need it fixed or a roof replacement. Many leaks can be easily fixed. A leak unnoticed for a long length of time can lead to serious mold issues. It can also do damage to insulation and cause many other more structural issues. Finding the right Calgary Roof Repair Contractor to identify and treat a leak with expertise can be a drawn out process. General Roofing Systems Calgary has expert leak detection technicians. We are on-call 24 hours a day 365 days a year for Emergency Roofing.