Tear-off vs overlay

Replacing a roof two ways: strip it to the deck first (tear-off), or nail the new roof over the old one (overlay, also called a roof-over or re-cover). Overlay quotes come in lower. They are not the same job.

The price difference

Tear-off and disposal of one layer typically accounts for roughly $1.00–$2.00 per sq ft of the installed price — on a 2,000 sq ft roof, an overlay can quote $2,000–$4,000 lower. Our standard ranges assume tear-off; an overlay quote below the range is not automatically a bargain, it is a different scope.

What tear-off gets you

• The deck is inspected. Rotten or delaminated sheathing is found and fixed — the #1 hidden cause of "new roof, still leaks".
• New underlayment and ice-and-water shield go down on a clean, flat surface.
• Flashing is replaced properly instead of layered over old flashing.
• Full manufacturer warranties typically apply; many shingle warranties are reduced or voided over an existing layer, and most manufacturers allow only one overlay, ever.

When an overlay can make sense

• The existing roof is a single layer, lies flat, and the deck is verifiably sound (attic inspection, no soft spots).
• Budget is the hard constraint and the plan is to sell or re-roof properly within the overlay's shorter life.
• Local code allows it — many jurisdictions cap roofs at two layers total, and some ban overlays on certain structures.

When it does not

Two existing layers, curled or brittle shingles, any sign of deck rot, sagging, or a premium material going on top (metal, tile and slate should never be overlaid — the weight and fastening assumptions fail). An overlay also adds the old roof's weight to the structure permanently.

The rule of thumb

If you plan to stay in the house, tear off. The saving is real but small against a 25–30-year asset, and the tear-off is the only moment anyone ever sees your deck. If a contractor pushes an overlay without an attic/deck check, that tells you something about the contractor.