The Roof Supplement Guide — How to Get Paid in Full on Every Claim
A complete, step-by-step process for supplementing a roof insurance claim — from getting the adjuster's estimate to submitting your request and handling denials.
What is a roof supplement?
A supplement is a formal, written request to the insurance company to revise their estimate upward — adding missing line items, correcting wrong codes, or adjusting under-measured quantities. Supplementing is a standard, expected part of the claims process, not a dispute or complaint.
On a typical residential roof replacement, the gap between a carrier's initial estimate and a properly-scoped job is $2,000–$6,000. Roofers and public adjusters who supplement systematically recover this on every claim. Those who don't either absorb the loss or do the work for less than it costs.
The supplement process — step by step
Get the adjuster's line-item estimate
Always request the full Xactimate line-item breakdown — not just the summary page or total. The line-item detail shows every code, quantity, and unit price. This is what you'll compare against your own scope.
Build your own scope from scratch
Don't start from the adjuster's estimate — build your own scope independently based on your site inspection and measurements. This ensures you catch items they missed rather than anchoring to their version.
Compare line by line
Go through every line item in your scope and check whether it appears in the adjuster's estimate, at the right quantity, and at the right code. Missing items, wrong codes, and under-measured quantities are all supplementable.
Document every discrepancy
For each supplemented item, gather supporting evidence: photos showing the condition, measurements, manufacturer specs, and local building code citations where applicable.
Write and submit the supplement request
Submit your supplement as a written document — not a phone call. Include the specific Xactimate codes you're adding or correcting, the quantities, your justification, and the supporting documentation.
Follow up until approved
Most supplements take 1–3 weeks. If you haven't heard back in 5 business days, follow up in writing. If a supplement is denied, request the specific reason in writing and respond to each denial point individually.
The 10 most common roofing supplement items
These items appear in the vast majority of successful roof supplements. Check every one on every claim.
| # | Item |
|---|---|
| 1 | Starter shingles (RFG 226) |
| 2 | Drip edge (RFG 270) |
| 3 | Ice & water shield (RFG 358) |
| 4 | Synthetic underlayment upgrade (RFG 356) |
| 5 | Steep slope pitch adder |
| 6 | Pipe boots (RFG 290) |
| 7 | Multi-layer tear-off adder (RFG 181) |
| 8 | Shingle grade upgrade (RFG 242 vs 240) |
| 9 | Ridge vent (RFG 310) |
| 10 | Overhead & profit (O&P) |
How to handle supplement denials
Every denial has a specific response. Don't accept a denial at face value — address the stated reason directly.
Find every supplement item in minutes
Appraisly compares your roofing estimate to the insurance company's Xactimate scope line by line — automating the comparison that takes contractors hours to do manually.