Roof replacement costs in Thornhill typically range from $8,000 to $20,000 for a standard single-family home, depending on roof size, pitch, materials, and tear-off requirements. Asphalt shingles are the most common choice and the most affordable. Metal roofing, while more expensive upfront at $15,000 to $35,000, can last 40 to 70 years. Always get at least two written quotes.
Common signs include shingles that are cracked, curled, or missing in multiple areas; granules accumulating in gutters; visible daylight through the attic; water stains on ceilings or interior walls; and a roof that is more than 20 to 25 years old. A professional roof inspection can confirm whether repair or full replacement is the right call.
Ask for proof of WCB/WSIB coverage and general liability insurance, as roofing is a high-risk trade. Request a detailed written quote specifying the materials, manufacturer, and warranty terms for both shingles and installation labour. Ask whether the old roofing material will be removed and disposed of, and whether the quote includes ice and water shield along the eaves.
Most residential roof replacements in Thornhill are completed in one to two days for a standard home. Larger or more complex roofs with multiple peaks, valleys, or steep pitches can take three to five days. Weather plays a major role, particularly in Thornhill's climate, so your contractor will need dry conditions. Ask for a start date and estimated completion window in writing.
Requirements vary by municipality. Many cities require a permit for a full tear-off and re-roof but not for an overlay or minor repairs. Your roofing contractor should know the local requirements and handle permit applications on your behalf. Skipping a required permit can cause problems when you sell your home and may void your shingle manufacturer warranty.
