What Is a Supplemental Roofing Estimate, and Who Asks?

Updated 2026-10-24 · Sources checked

"Why would I be on the hook for dry rot?"

A commenter in a roofing thread asked that, and it is the fear behind the supplement question.

A supplement is a request to add items the first estimate missed to the claim you already have open. It is a request, not a promise. In Texas, if the damage is worse than the adjuster first thought, you or your contractor can talk to the adjuster about raising the estimate¹.

Quick answer:

Lay the adjuster's estimate next to the roofer's and mark every item that appears on only one of them.
Photograph each problem with the date, and keep every receipt and invoice.
Ask your insurer how to send a supplement and how long you have.
Hold off on signing anything until you have the roofer's written, line-by-line estimate.

On this page

What is a supplement, and is it different from disputing the claim?
Why the insurer's estimate can come in short
Who asks for a supplement, and what proof does it need?
Is there a deadline?
Checklist: compare the two estimates line by line
Red flags before you sign
Quick questions

A gap between the two numbers is a question to put to your insurer, not a final answer.

What is a supplement, and is it different from disputing the claim?

Yes, it is different. A supplement adds to the estimate. A dispute says the estimate itself is wrong.

In Florida, a supplemental claim is a claim for additional loss or damage from the same peril that the insurer has previously adjusted². Wherever you live, your policy has its own terms.

If you disagree with the adjuster's estimate or the amount offered, that is a different step: in Texas, tell the insurance company why you disagree¹. Our guide to the roof insurance adjuster walks through what can come after.

Why the insurer's estimate can come in short

Your roofer may point to items like decking (the wood boards under the shingles) that turn out to be damaged once the old roof comes off. A forum reply puts the gap simply:

"The insurance estimate is different than the cost of replacing / rebuilding."

Ask the roofer for a photo of each item, so you can check the extent of the damage yourself.

Drip edge, the metal strip along the roof's edge, is another item that can show up. Drip edge and similar metal flashings should be installed as local building code, industry recommendations or the manufacturer require³, so a roofer may list it as code work.

Code work is where the money surprise can sit. The standard HO-3 homeowners policy excludes costs caused by laws that regulate construction⁴, and an Ordinance or Law endorsement is the add-on that covers the extra cost of meeting new building codes. Take a house near the ocean that a new building code would require to be rebuilt on stilts: that would add $30,000 to the cost of rebuilding⁴. That is a coastal rebuild, not a roof job. Your numbers will differ.

In California, unless your policy has language covering the added cost of code changes, you may pay non-reimbursable expenses to rebuild to present codes⁵. Whether your policy has that language is for your policy to say.

Who asks for a supplement, and what proof does it need?

In Texas, you or your contractor can talk to the adjuster¹ about raising the estimate. A roofer may send the paperwork, as the same commenter put it:

"You should replace it, but have your roofer send your insurance company the supplemental invoices."

Proof is what makes the request more than an opinion. In Washington, be ready to provide receipts, photos and similar proof of your loss⁶. Ask your roofer which of these they will attach for each item.

Wondering who pays if rotted wood turns up that the estimate left out? What roof rot means and what to get in writing.

Is there a deadline?

Florida: a supplemental claim is barred unless notice was given to the insurer, as the policy's terms require, within 18 months after the date of loss².
California: if more damage is discovered later, you can reopen the claim and request additional compensation⁵.
Anywhere else: read the notice terms in your policy and ask your insurer how long you have⁷.

Checklist: compare the two estimates line by line

In Texas, get multiple bids from contractors and compare them with the adjuster's report before settling the claim⁸. Use these steps wherever you live.

Mark each line that is on the roofer's estimate but not the adjuster's.
Label each one: decking, flashing or drip edge, code work, or something else.
For each, ask the roofer why it is needed and whether it was visible before the tear-off.
Questions for your insurer: how a supplement is sent, what documents it needs, and whether your policy has an Ordinance or Law endorsement⁴.
Gather your dated photos, receipts and both estimates in one folder.

Want more help reading two estimates side by side? How to compare roof estimates when the totals don't match.

Red flags before you sign

Some roofers inflate the paperwork. In Texas, one way a contractor covers your deductible is an estimate higher than the actual cost to repair⁹, with the extra insurer money used to cover it. There, a contractor who asks you to sign something before giving you an estimate of repairs¹⁰ is a sign of a scam.

Ask the roofer for a line item bid that prices each supplement item separately, and ask them to agree that no extra work starts without your signed change order. You can send this:

Please list each supplement item on its own line: what it is for, where it is on the roof, and its price. Please send a photo of each item and tell me how you will submit them. I will not sign until I have this.

If a roofer pushes you to sign today or won't put this in writing, that is an answer too: weigh it against the bids that do. If the roofer hands you a form so they can handle the claim for you, ask what it lets them do and what you would owe for an item that is turned down. Ask for a copy before you sign.

Claim Letter Decoder: the numbers on your insurer's letter

Type the numbers from your insurer's estimate or settlement letter. You'll see the arithmetic behind the payment, what to ask in writing, and a message you can send. Nothing you type leaves this page.

Your browser isn't running scripts, so here is the general version, with a worked example from Montana instead of your numbers.How the payment is figured

Actual cash value: an actual cash value policy pays the amount needed to replace the item minus depreciation.¹¹

Montana's example: $20,000 to replace the roof, minus $10,000 (50% depreciation), leaves $10,000; the 2% deductible on $250,000 of coverage is $5,000; with actual cash value only, the homeowner pays $15,000 after insurance.¹⁸

A percentage deductible is figured on the amount the house is insured for: at 2 percent on $100,000, $2,000 is deducted from any claim payment.¹²

With replacement cost coverage: in Missouri, the company first pays the actual cash value and releases the withheld depreciation once repairs have actually been made. In North Carolina, the company generally reimburses it once the work is done and receipts are submitted.^15,16

With actual cash value only: depreciation is factored into your final payout, rather than replacement cost value.¹⁹

What to ask in writingPut these to your adjuster or insurer in writing, and keep their answers with the letter.

Does my policy pay replacement cost on the roof, or only actual cash value?

Which documents release any held-back depreciation, and by what date? In Missouri, many policies specify a replacement cost timeframe of 12, 18 or 24 months.¹⁵

If the estimate left out items, or more damage turns up during the work, how do I add them to this claim?

Your policy and your insurer's letter decide what is paid.

Quick questions

What is the 25% rule for roofing? In Florida, the rule covers a roof built, repaired or replaced to the 2007 Florida Building Code or later¹¹. When 25 percent or more is repaired, replaced or recovered, only that portion has to meet the code¹¹. Ask your roofer which code your roof was built under and whether the rule applies.

How do you estimate what a new roof will cost? No one can give a fair figure from a distance, because it depends on what the roofer finds under the old roof. Ask which items are firm and which depend on what turns up once the old roof is off.

Can I cash the check and still ask for more later? Yes. With an on-the-spot settlement, you can accept the check⁷. If you later find other damage, you can reopen the claim and file for more⁷. Your policy and state set the time limit.

What if the insurer turns down part of a supplement? Ask the roofer before work starts who pays for an item the insurer does not approve, and put the answer in the contract.

Sources

1. Texas Department of Insurance, Home insurance guide

2. Florida Legislature, Florida Statutes section 627.70132: Notice of property insurance claim

3. Insurance Institute for Business & Home Safety, Metal Flashing

4. Insurance Information Institute, Am I Covered?

5. California Department of Insurance, Residential Property Claims Guide

6. Washington State Office of the Insurance Commissioner, Filing a homeowner insurance claim

7. Insurance Information Institute, Settling insurance claims after a disaster

8. Texas Department of Insurance, Help after a storm (Repairing your home)

9. Texas Department of Insurance, Is it OK for a contractor to waive my deductible?

10. Texas Department of Insurance, Do you know the signs of a contracting scam?

11. Florida Legislature, Florida Statutes section 553.844: Windstorm loss mitigation; requirements for roofs and opening protection

Also cited by the Claim Letter Decoder tool on this page:

11. Triple-I (Insurance Information Institute): How is the settlement amount determined?

12. Triple-I (Insurance Information Institute): Understanding your insurance deductibles

13. Texas Department of Insurance: What to know about deductibles

14. Texas Department of Insurance: Home insurance policies: Replacement cost or actual cash value?

15. Missouri Department of Commerce and Insurance: Missouri Department of Commerce and Insurance continues to provide post-disaster consumer support, addresses questions on supplemental claims and recovery process

16. North Carolina Department of Insurance: Actual Cash Value vs. Replacement Cost Value

17. Texas Office of Public Insurance Counsel (OPIC): What is a deductible?

18. Montana Commissioner of Securities and Insurance: Insurance may not cover a hail-damaged roof

19. Triple-I (Insurance Information Institute): How Your Roof Influences Your Home and Business Insurance

20. Texas Department of Insurance: Insurance and your roof: What to know when buying a policy or filing a claim

21. Iowa Insurance Division: Consumer Connection: Roof Coverage Options

22. Maryland General Assembly (Maryland Code, Insurance Article): Maryland Code, Insurance, section 19-213

23. North Carolina Department of Insurance: Windstorm and Hail

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