How to Read a Roofing Estimate: Line-by-Line Guide

A roofing estimate can be confusing with its industry terminology and varying levels of detail. Understanding what each line item means helps you compare bids accurately and spot missing items that could lead to surprise charges. Here is a breakdown of what a complete roofing estimate should include.

What a Complete Estimate Should Contain

A professional roofing estimate should be detailed and transparent. Vague one-line quotes like "Reroof: $12,000" are red flags. Here are the key sections:

Section 1: Tear-Off and Removal

  • "Remove existing roofing (X layers)" — Cost to strip old shingles down to the deck. Should specify the number of layers being removed. Expect $100–$175 per square.
  • "Dumpster / disposal fee" — Some contractors include this in tear-off; others list it separately. A 20-yard dumpster costs $300–$600.
  • "Haul-away" — Debris removal fee if not included in dumpster cost.

Section 2: Deck Repair

  • "Replace damaged sheathing (per sheet)" — Cost per 4x8 sheet of OSB or plywood. Should quote a per-sheet price so you know the rate if more damage is found than expected. Typical: $50–$100 per sheet installed.
  • "Deck inspection" — Note that full deck condition cannot be assessed until the old roofing is removed. A good estimate includes a per-sheet rate for any additional repairs needed.

Section 3: Underlayment

  • "Synthetic underlayment" — Full-roof coverage under the shingles. Should specify the brand and type (e.g., GAF FeltBuster, CertainTeed DiamondDeck).
  • "Ice and water shield" — Self-adhering membrane at eaves, valleys, and penetrations. Should specify where it will be installed and how many feet up from the eave.

Section 4: Roofing Material

  • "Architectural shingles (brand/line/color)" — The main roofing material. Should specify exact brand, product line, and color. Example: "GAF Timberline HDZ, Charcoal." Priced per square installed.
  • "Starter strip shingles" — Installed along eaves and rakes under the first course.
  • "Hip and ridge cap shingles" — Covers the ridge and hip lines. Should be the matching product.

Section 5: Flashing and Accessories

  • "Drip edge" — Metal edging along eaves and rakes. Should be included — it is code-required in most areas.
  • "Valley flashing" — Metal or woven/cut valley treatment. Should specify the method.
  • "Step flashing" — Where the roof meets walls. Should be new, not reused.
  • "Chimney flashing" — Counter flashing around chimneys. Should specify if it includes replacing lead or aluminum base flashing.
  • "Pipe boot / vent flashing" — Rubber boots around plumbing vent pipes. Always replace with the new roof.

Section 6: Ventilation

  • "Ridge vent" — Continuous vent along the ridge. Should specify brand and linear feet.
  • "Soffit vents" — If intake venting is being added or replaced.

Use our Roof Ventilation Calculator to verify the ventilation quantities on the estimate.

Section 7: Other Costs

  • "Building permit" — Should be included. If missing, ask who is responsible.
  • "Steep-slope charge" — Additional cost for pitches over 7/12 or 8/12. Legitimate surcharge of 10–25%.
  • "Multi-story charge" — Additional labor for 2+ story homes.
  • "Warranty" — Should specify both manufacturer and workmanship warranty terms.

Red Flags in Roofing Estimates

  • No brand/product specified: "Architectural shingles" without a brand lets the contractor use whatever is cheapest.
  • No underlayment listed: It is probably included but not itemized — or worse, they plan to skip it.
  • No ice and water shield: Required by code in cold climates. If missing, ask specifically.
  • No drip edge: Code-required in most jurisdictions. A surprising number of contractors skip it.
  • "Reuse existing flashing": Flashing should be replaced with a new roof. Reusing old flashing is a top cause of leaks within 5 years of a reroof.
  • Lump-sum pricing: Without line items, you cannot compare bids or verify what is included.

How to Compare Bids

  1. Create a spreadsheet with every line item from the most detailed bid
  2. Fill in prices from each contractor for each item
  3. Identify items that some bids include and others do not
  4. Ask contractors to clarify or add missing items
  5. Compare the total with missing items equalized

Use our Roof Replacement Cost Calculator to generate a benchmark estimate for comparison.

Frequently Asked Questions

Should I always choose the lowest bid?

No. The lowest bid may be missing essential items, using inferior materials, or reflect uninsured labor. Focus on the bid that provides the best combination of complete scope, quality materials, proper warranties, and reasonable pricing. A bid 10–15% below average may be fine; 30% below average is a warning sign.

What if the contractor finds more damage during tear-off?

Good estimates include a per-sheet price for deck repair and a process for approving additional work. The contractor should contact you before proceeding with unquoted repairs. Get this process in writing before work begins.

Are verbal estimates acceptable?

Never. Always require a written estimate with detailed line items, signed by the contractor. Verbal quotes provide zero protection and lead to disputes over scope and pricing.