How to Compare Roofing Bids

This is the biggest cost variable. Tear-off ($1–3/sqft extra) removes existing shingles, exposes the deck for inspection, and gives the new roof a clean start. Overlay goes over existing, saves labor, but hides problems and shortens the new roof's life. Bids must specify the same approach to be comparable.

Architectural shingles span GAF Timberline HDZ (benchmark) to generic big-box brands. The price difference is 30–40% on materials, but more importantly, the warranty tier changes dramatically. Each bid must name the manufacturer and product line. Comparing "architectural shingles" without the brand is comparing unknowns.

Legitimate bids include: synthetic underlayment over full deck, ice and water shield at eaves/valleys/penetrations (cold climates), new metal drip edge, new flashing at all chimneys/walls/pipes, and ridge vent. Get a per-component breakdown from any bid that does not itemize these. Missing even one item can be a $500–$2,000 change order.

At least 30% of roofs have rotted decking discovered during tear-off. The time to price this is before signing — not after the old roof is off. Each bid should include a per-sheet rate for decking replacement. If one bid excludes this and others include it, add the likely cost (estimate 5–10 sheets at $50–$75/sheet) to the low bid for fair comparison.

GAF Master Elite, CertainTeed ShingleMaster, and OC Platinum Preferred contractors unlock enhanced warranty programs with 10–25 years of labor coverage. A basic installer gives you material-only warranty. Ask each contractor their certification level — it affects the warranty you receive, not just the installation quality.

Standard roofing payment: 10–15% deposit, materials payment on delivery (so you can verify them), final payment after completion. Demand for full payment before materials arrive is a red flag. Also: verify each contractor has a local address and license registered in your state — not just a phone number.