Roofing Supplements: From Field Inspection to Approved Scope

Satellite estimates vs field measurements

Most adjuster roof estimates start with EagleView or Hover satellite measurements. These reports are convenient but routinely miss 5-15% of actual roof area. They undercount waste factor on complex roof lines, miss small dormers or bump-outs, and can not account for the actual pitch measured from the decking.

Your field measurements are the ground truth. Measure every plane, every valley, every hip. Use a pitch gauge on the decking, not the shingles.

A satellite report that says 28 squares on a roof that actually measures 32 squares is $1,200 to $2,000 in missing material and labor right there. When you submit your supplement, include your field measurements alongside the satellite report with a clear comparison showing the discrepancy. Adjusters understand that satellite measurements are estimates.

If your field numbers are documented with photos showing the tape measure on the decking, they'll adjust.

Shingle matching and discontinued colors

When the adjuster specs a shingle color that has been discontinued, you have a matching argument. Insurance policies require repairs that match the pre-loss condition. If Owens Corning Driftwood is no longer manufactured and the existing roof is Driftwood, the entire roof may need replacement to achieve a uniform appearance.

This is not an upgrade. This is a matching requirement. Document the existing shingle color with close-up photos in natural daylight.

Contact the manufacturer to get written confirmation that the color has been discontinued. Check whether a close match exists in the current product line. If the closest match is visibly different, photograph both samples side by side.

Some adjusters will approve full replacement immediately when you provide the manufacturer discontinuation letter. Others will push for the "closest available match" and require you to demonstrate the visual difference. Either way, the documentation starts with proving what is currently on the roof and confirming it is no longer available.

Code-required underlayment and ice/water shield

Building codes have changed significantly in the last 10 to 15 years. If the roof being replaced was installed under older codes, the replacement must meet current code. This is a legal requirement, not a preference.

In most jurisdictions, current code requires synthetic underlayment instead of 15-pound felt paper. The cost difference is $0. 50 to $1.

50 per square foot, which on a 30-square roof adds $1,500 to $4,500 to the job. Ice and water shield is required in cold climates along eaves, typically extending 24 inches past the interior wall line. In areas with freeze-thaw cycles, this is code, not optional.

Drip edge at eaves and rakes is required by IBC and IRC codes. If the existing roof did not have drip edge, the replacement must include it. Pull your local building codeYour Walls Are Open. Now the Inspector Wants $5,000 in Upgrades.Nobody warned me about this one. When the drywall came down on my claim, I thought we were just replacing what got damaged. Then the building inspe...
Read more → requirements before you submit the supplement.

Reference the specific code section in your scope line. "Install synthetic underlayment per [City] Building Code Section 1507. 1.

1, required on all re-roofing projects" is far more effective than "upgrade underlayment.

Flashing at walls, chimneys, and valleys

Step flashing at walls and chimneys is one of the most frequently missed items on roof supplements. When you tear off the shingles and expose the step flashing, you often find corroded, bent, or improperly lapped pieces that need full replacement. Each piece of step flashing is a separate installation at every course of shingles where the roof meets a vertical wall.

Counter flashing at chimneys requires cutting a reglet into the mortar joint and sealing with appropriate sealant. Valley flashing takes a beating from water concentration and often needs replacement even when the adjuster only scoped shingle replacement. Document every piece of flashing with close-up photos showing the condition.

Corroded step flashing that's paper-thin won't protect the wall intersection for the 20 to 30 year life of the new shingles. That argument is straightforward and adjusters generally approve it when the photo evidence is clear.

Decking replacement for rotted sections

You won't know the decking condition until the shingles and underlayment come off. Rotted or delaminated plywood decking is common on roofs with long-term leak issues, especially around valleys, chimneys, and areas where ice dams form. OSB decking that has been exposed to moisture delaminates and loses structural integrity.

You can identify it by pressing with your thumb. If the surface gives or feels spongy, it needs replacement. Photograph every sheet of damaged decking from above, showing the extent of the damage.

Measure the square footage and note the material type and thickness. Standard replacement is 7/16-inch OSB or 1/2-inch CDX plywood at $1. 50 to $3.

00 per square foot installed. On a roof with 200 square feet of rotted decking, that's $300 to $600 in additional scope. Some adjusters want to see the damaged decking in person before approving.

If your adjuster is responsive, call them out to the site before you cover it up. If they are not responsive, detailed photos with measurements will support the supplement.

Interior damage from roof leaks

Roof leaks cause interior damage that belongs on the same claim. Water that enters through a compromised roof travels down rafters, soaks insulationFiberglass, Blown-In, or Spray Foam: What R-Value Means for Your ClaimInsulation is rated by R-value: resistance to heat transfer. Higher R-values mean better insulation. When your repair opens wall or attic cavities,...
Read more →, stains ceiling drywall, and can damage walls and flooring below. Check the attic for wet or compressed insulation, water staining on rafters, and active drip paths.

Inside the living space, look for ceiling stains, bubbling paint, and soft spots in the drywall. Interior repairs on a roof claim commonly include drywall replacement (ceiling and sometimes upper walls), insulation replacement in the attic, painting to match existing finish, and light fixture replacement if water damaged the electrical. These items are often scoped as a separate interior section of the estimate.

If the adjuster only wrote a roof estimate with no interior line items, submit the interior scope as a supplement with photos showing the water path from the roof penetration to the interior damage.

Permits and the supplement opportunity

Most jurisdictions require a permit for a full roof replacement. Permit fees vary from $150 to $1,500 depending on the municipality and the scope of work. This is a legitimate cost that belongs in the estimate.

Many adjuster estimates leave permits off entirely. Beyond the fee itself, permit requirements often trigger code upgrades that generate additional scope. When the building inspector reviews the permit application, they may require upgraded ventilation, additional ice and water shield, or specific underlayment materials.

These code-triggered items are supplementable because they are required by the authority having jurisdiction, not by contractor preference. Include the permit fee in your initial estimate or first supplement. Reference your local building department requirements.

If the adjuster pushes back on permit costs, provide the fee schedule from the building department website. It's a hard cost with a published rate, which makes it one of the easiest supplement items to get approved.