Your roof takes a beating from Ontario winters. We replace it right the first time — no shortcuts, no surprises. Owens Corning Preferred certified since 1998. Professional roof replacement is the complete removal and reinstallation of your home's roofing system, including shingles, underlayment, and flashing. In Ontario, a full roof replacement typically takes 1-3 days and costs between $5,200 and $25,000 depending on home size, material choice, and roof complexity (based on 2026 Ontario pricing from Custom Contracting's 3,700+ completed installations).