An overlay is when new architectural shingles are installed directly over the old layer, while a tear-off means completely removing the old shingles before putting on new ones. Overlays can save time and money because the old roof doesn’t need to be hauled away, and less labor is involved. However, this method adds extra weight to your roof deck and can hide potential problems like rotten wood, which might cause leaks or structural damage later. Tear-offs allow for a fresh start, making it easier to inspect and fix any damage, but it’s more costly and disruptive. Simple DIY checks before deciding include inspecting your roof from the ground or a ladder to see if the shingles are badly curled, cracked, or missing granules. If the existing roof is in rough shape or if you’ve already done one overlay in the past, a tear-off is usually the safer bet.
When considering a roofing project, knowing the limits of a DIY inspection is essential—you can look for curling shingles, signs of sagging, or obvious wear, but you won’t catch what's beneath the layers. Calling a professional roofer is best if your roof is over 15-20 years old, or if you see leaks or damaged vents and flashing. When you speak with a contractor, ask, “Based on my roof’s current condition, would you recommend an overlay or a full tear-off, and why?” Also, inquire about how an overlay might affect your shingle warranty and the structural integrity of your roof. Contractors should provide clear answers on building code compliance because some areas restrict overlays to prevent added weight risks. Getting these details upfront helps make a choice that keeps your roof secure and your home protected over the long haul.