A roofing insurance supplement is a written request for additional payment on a claim, based on items the insurer's original scope left out or underpriced. Writing one well isn't about arguing — it's about comparing the adjuster's scope against what the job actually requires and documenting the difference so clearly that approving it is the easy answer.
Step 1: Review the Adjuster's Scope Line by Line
Start with the insurer's estimate, not your own. Go through every line item and match it against your measurements, your photos, and the manufacturer's installation requirements. You're looking for three things: items that are missing entirely, quantities that don't match the actual roof, and unit prices that don't reflect current local material and labor costs.
Step 2: Find the Gaps
Most supplements come from a short list of recurring gaps. Check these first:
- Code-required items the scope skipped, like ice and water shield, drip edge, or updated ventilation — cite the specific code section your jurisdiction has adopted
- Quantities that don't match your measurements (roof area, ridge/hip length, valley length, penetrations)
- Detach-and-reset or tear-off items tied to the roof but scoped under a different trade (gutters, satellite dishes, solar mounts)
- Steep-slope, high-roof, or multiple-layer tear-off charges left off the original scope
- Overhead and profit (O&P), when the job involves three or more trades or otherwise meets the carrier's own threshold for coordination
O&P is one of the most misunderstood line items in a supplement. If you're not sure when it applies or how to justify it, we cover the mechanics in our post on overhead and profit on roofing claims
Step 3: Document Everything Before You Write a Word
A supplement lives or dies on documentation, not adjectives. For every item you're adding, attach proof:
- Photos showing the specific condition (rotten decking, missing flashing, inadequate ventilation)
- Measurements from your own report, sourced from an aerial or on-roof measurement tool
- The exact code citation and jurisdiction, quoted directly rather than paraphrased
- Manufacturer installation instructions when the requirement comes from the shingle or system warranty rather than code
- Current material and labor pricing from a source the adjuster can verify
Adjusters often use a general line-item pricing tool that doesn't reflect every local requirement. That's exactly why certain items get left off scopes over and over. We break down the most common ones in commonly missed items in roofing supplements
Step 4: Write the Supplement
Keep the document itself simple: claim number, date of loss, and a line-by-line list of additions. For each line, state what's being added, the quantity, the unit price, and a one-line reason with a reference to the attached photo or code citation. Avoid opinion language — "appears damaged" or "in our experience" won't move an adjuster. A code section number or a measurement discrepancy will.
Step 5: Submit and Follow Up
Send the supplement to the adjuster with all backup attached in one package, not as a series of follow-up emails. Give it a specific ask: approval of the listed items, or a written explanation of what's being denied and why. Follow up on a set schedule rather than waiting on the insurer to respond first — claims move faster when someone is tracking the timeline.
Step 6: Escalate If Needed
If an item is denied without a clear reason, ask for the specific basis in writing. From there, you can request a re-inspection, involve the homeowner's agent, or point to the carrier's own published guidelines if the denial conflicts with them. Escalation paths and appraisal rights vary by state and by policy, so treat this as general information, not legal or financial advice — when a claim stalls, a public adjuster or attorney familiar with local rules is the right resource, not a contractor's estimate alone.
See how supplement conversion works
The whole process is really just three habits repeated on every claim: compare the scope to the real roof, back up every gap with a photo or a code citation, and keep the paper trail organized enough that anyone reviewing it later can follow your logic in under a minute.