What factors go into a roof replacement quote?
Short answer. A roof replacement quote is driven by roof size in squares, pitch, complexity, how many layers come off, decking condition, the shingle line and accessories, flashing and ventilation work, permits and disposal, and the warranty behind the job. Two quotes for the same house usually differ because they include different items in those categories.
The main quote factors
- Size and shape: total squares, plus how many hips, valleys, dormers, and roof planes the crew must cut around.
- Pitch: slopes steeper than about 7/12 slow crews down and require more safety equipment.
- Tear-off: one layer or two, and whether old roofing hides problems like plank decking with gaps.
- Decking: how damaged sheathing is handled. Good quotes state a per-sheet price so there are no surprises.
- Material system: the shingle line, synthetic underlayment, leak barrier in valleys and around penetrations, drip edge, starter strip, and ridge cap. Using the manufacturer's matching components keeps upgraded warranties available.
- Flashing: new step flashing at walls, properly reworked chimney flashing, and new pipe boots instead of reusing old ones.
- Ventilation: ridge vent, box vents, or a correction of mixed exhaust systems, balanced with soffit intake.
- Access and protection: landscaping, driveways, and tight lots change setup and cleanup time.
- Permit, dumpster, and disposal: local permit rules vary by city and county.
- Warranty: the length and terms of the workmanship warranty and which manufacturer warranty is registered.
How to use this list
Hand each bidder the same list and ask them to address every line in writing. Missing lines are either included without saying so or excluded, and you need to know which. For more detail, see how roofers measure a roof and roofing warranties explained.
If the replacement follows a storm, the insurance estimate becomes a major factor: the scope should match what the adjuster approved, with supplements for anything missed.