O'Hara's Son Roofing (OSR)

O'Hara's Son Roofing, also known as OSR, is a commercial roofing contractor focused on flat roofs. Its listed services cover new construction, reroofing, preventive maintenance, leak repair, specialty roofing and cold storage work, with a stated emphasis on safety and crew protocols.

OSR works with commercial properties across the country and is based on North Avondale Avenue in Chicago. The company lists 24/7 emergency response, and a separate 24-hour leak line for urgent roof leaks. Office hours are weekdays during business hours, and requests can also go through its online quote form.