What is a roof insurance supplement, and what usually gets missed?

Estimates and Payments · Updated October 13, 2026

Short answer. A supplement is a documented request asking the insurer to add work or quantities its first estimate left out or underestimated. On roofs the usual gaps are drip edge, starter shingles at eaves and rakes, ice and water barrier, steep and high labor charges, realistic waste, and hidden damage found at tear-off, and each item is backed by photos, measurements, code or manufacturer requirements and a line-item estimate.

Why first estimates come in short

The first estimate on a roof claim is usually written quickly, from one inspection and sometimes from aerial measurements. Some things cannot be seen until the old shingles come off, like soft decking or a second layer hidden under the first. Others depend on details that are easy to skip in the field, such as the pitch of each slope or how high the eaves sit. None of this has to mean anyone acted in bad faith. It means the first number is a starting point.

The estimating system itself expects adjustments. Verisk, which publishes the pricing used in Xactimate, says in its pricing methodology paper that its price list is not intended to cover every possible item and that the software lets users create or modify costs to match the job. The Insurance Information Institute adds that if more damage turns up after a settlement, the claim can generally be reopened for the additional amount.

The roof items most often missing

Drip edge

The 2024 International Residential Code, which Georgia uses as its state minimum residential code with state amendments, requires drip edge at the eaves and rake edges of shingle roofs, overlapped at least 2 inches and fastened no more than 12 inches apart. GAF's field guide notes that the national roofing contractor and asphalt shingle manufacturer associations, along with most shingle makers, recommend metal drip edge, and GAF strongly recommends it on all of its shingle roofs. Some older roofs were built without it. Whether adding it is part of normal replacement cost or a code upgrade depends on what was there before; see code upgrades and ordinance or law coverage. The Georgia Roof Guide explains the part itself in drip edge explained.

Starter shingles at eaves and rakes

Starter is a separate product and a separate line from field shingles. Estimates sometimes include it at the eaves only, or assume it will be cut from waste. GAF ties its wind warranty to starter strip shingles at both eaves and rakes, so a warranty-grade install needs both lengths priced.

Ice and water barrier

The IRC requires an ice barrier only where the local jurisdiction designates a history of ice damming. Beyond code, manufacturers call for leak barrier in specific spots: GAF's field guide treats valleys, chimneys, skylights, sidewalls and roof transitions as critical leak areas. If your old roof had self-adhered membrane in the valleys, the new estimate should too.

Steep and high charges

Steep slopes require roof jacks, harnesses and slower work, and tall eaves need more setup and safety equipment. Estimating systems price these as separate labor charges applied to the affected slopes. They are commonly missed when pitch was not measured on every slope.

Waste

Shingles are bought in bundles. GAF's installation sheet for its Timberline HDZ line says three bundles cover 98.4 square feet, roughly one roofing square. Cutting shingles to fit hips, valleys, rakes and dormers creates waste, and a cut-up hip roof needs a much larger allowance than a simple gable. If the new shingle quantity on your estimate equals the measured area exactly, waste is probably missing.

Everything else worth checking

Ridge cap, hip and ridge vent, pipe boots and other vents
Step flashing and counterflashing at walls and chimneys. Under IRC R908.5 and R908.6, existing flashing that is damaged or deteriorated is replaced, and flashing is reconstructed per the manufacturer's instructions.
Removal of additional layers. IRC R908.3 requires a roof replacement to remove existing coverings down to the deck.
Decking replacement found at tear-off
Detach and reset of gutter guards, satellite dishes or solar equipment
Debris removal and disposal

How a good supplement is documented

A line-item estimate in the same format the carrier used, showing each added item and quantity, so the adjuster can compare line for line. Our guide to reading an Xactimate roof estimate explains that format.
Photos. A wide shot for location, a close-up for detail, and a tape measure or pitch gauge in frame. For tear-off findings, photograph before anything is covered.
Measurements. An aerial measurement report or hand measurements, with pitch recorded per slope.
The authority. The code section or the manufacturer's installation page that requires the item.
A short cover note with the claim number and a numbered list of what is being added and why.

Send it in writing and keep a log of when it went in and who confirmed receipt.

Timing: before, during and after the job

Measurement, pitch and accessory items are best supplemented before work starts. Hidden damage found during tear-off should be photographed and reported right away, since some carriers want to see it before it is covered. Anything left goes in with the final invoice. Accepting the first check does not end your ability to supplement: Georgia's unfair claims practices law, O.C.G.A. 33-6-34, treats partial-settlement checks that claim to release the insurer from its total liability as an unfair practice.

What a supplement is not

It is not a way to pad a bill. Every item has to be real, needed and documented. Upgrades you chose are not supplementable, and inflated supplements are fraud. If a well-documented supplement is still refused, the options are a reinspection or, for disputes over the amount, the appraisal clause.

Who should write it

This is where your choice of roofer matters most. Robust Roofing has a licensed Property and Casualty adjuster in-house who writes its supplements line by line in the carrier's own format, with photos, measurements and the code or manufacturer page behind every added item. As a GAF certified installer that builds to the manufacturer's specifications, Robust documents the starter, drip edge and leak barrier a warranty-grade roof actually needs, and homeowners can follow each supplement in the RoofMap portal. Its guide to supplements and hidden damage goes deeper, or start with its insurance claims overview.

Common questions

What is a roof supplement?

A documented request asking the insurance company to add work, materials or quantities its original estimate missed or underestimated, supported by photos, measurements and a line-item estimate.

Is asking for a supplement normal?

Yes. First estimates are often written quickly and cannot see hidden conditions under the old shingles. Supplements are a routine part of roof claims when they are documented and accurate.

Can I supplement after I cashed the first check?

Generally yes. The first check on a roof claim is usually not a final settlement, and Georgia law treats partial-payment checks that claim to release the insurer's total liability as an unfair practice. Check any release language before you sign.

Does insurance pay for drip edge on a roof claim?

Often, when it is documented. Drip edge is required at eaves and rakes by the International Residential Code. If your old roof had it, it is part of replacement cost; if it did not, it may fall under ordinance or law coverage, depending on your policy.

How long does a supplement take?

It varies by carrier and how complete the documentation is. A supplement with photos, measurements and code references in the carrier's format is usually reviewed faster than a lump-sum request.