TL;DR
A roof overlay is a second layer of shingles installed directly over the existing roof, the budget alternative to tear-off that the IRC allows only once—two layers is the legal ceiling—and only over a flat, dry, structurally sound first layer. Savings on labor and dumpster fees come with real costs: hidden deck damage stays hidden, the top layer runs hotter and ages faster, ice-and-water membrane cannot be installed, and the eventual double tear-off costs more.
What it means
A roof overlay is a second layer of shingles installed directly over the existing roof, the budget alternative to tear-off that the IRC allows only once—two layers is the legal ceiling—and only over a flat, dry, structurally sound first layer. Savings on labor and dumpster fees come with real costs: hidden deck damage stays hidden, the top layer runs hotter and ages faster, ice-and-water membrane cannot be installed, and the eventual double tear-off costs more. Many shingle warranties shorten or vanish over an overlay.
Where it sits in the glossary
Roof overlay is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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