Xactimate Chimney Flashing: Base, Counter, and Cricket Supplements Explained

The adjuster approved a full roof replacement. They wrote shingles, underlayment, starter, ridge cap, and drip edge. Then they got to the chimney, typed in "R&R chimney flashing" as a single line item, priced it at 85 dollars, and moved on. You're standing on a roof with a 48-inch-wide masonry chimney that needs base flashing, step flashing up both sides, a counterflashing reglet cut into the mortar joints, and a cricket because the chimney exceeds 30 inches in width. That single 85 dollar line is missing roughly 1,200 dollars of real scope.

Chimney flashing is one of the most commonly underpaid details on residential roofing claims. Adjusters compress four or five distinct line items into one generic entry because they don't understand how the components work together or what the building code actually requires. The result is a claim that pays for a roof replacement but not a chimney flashing replacement, even though both are required for a warrantable, code-compliant install.

This guide breaks down each chimney flashing component, shows you the Xactimate line items for each, explains why full R&R is required any time the roof gets replaced, and gives you the supplement language that gets approved.

The Four Components of Chimney Flashing

A proper chimney flashing system is not one piece of metal. It is four distinct components working together to prevent water intrusion at one of the most vulnerable roof penetrations on the home.

Component 1: Base Flashing (Front Apron)

The base flashing, also called the front apron, runs across the downslope face of the chimney. It extends up onto the chimney face several inches and out onto the roof deck, woven into the shingle courses. It sheds water running down the roof away from the chimney base.

Component 2: Step Flashing (Sides)

Step flashing is a series of L-shaped metal pieces, typically 5 inches by 7 inches, installed one per shingle course up each side of the chimney. Each piece laps the one below it by at least 2 inches, creating a continuous waterproof barrier as the roof rises along the chimney sides.

Component 3: Counterflashing (Reglet)

Counterflashing is the upper layer of metal that caps the step flashing and base flashing. It's set into a reglet (a groove cut into the chimney mortar joints) and sealed. The counterflashing overlaps the step and base flashing to direct water away from the chimney-to-roof joint. Without a reglet cut, a surface-mounted counterflashing is a temporary fix at best.

Component 4: Cricket (Saddle) When Required

A cricket (sometimes called a saddle) is a small peaked structure installed on the upslope side of the chimney to divert water and debris around the chimney rather than letting it pile up against the back wall. The IRC requires a cricket on any chimney wider than 30 inches measured perpendicular to the slope.

Xactimate Line Items for Each Component

Xactimate has specific line items for each chimney flashing component. Writing them individually rather than using a single generic entry is the difference between an accurate estimate and a shortpaid one.

Notice that RFG CHIM (small chimney flashing package) is the generic entry many adjusters rely on. This line item is fine for a simple 16-inch-wide furnace vent chimney with no cricket. It is not fine for a 48-inch-wide masonry fireplace chimney with a required cricket and reglet-cut counterflashing. The components should be written line by line to match real scope.

For a deeper dive on step flashing specifically, including when adjusters miss it on walls and dormers, see Xactimate step flashing (RFG FLASH).

Why Full R&R Is Required With a New Roof

One of the most common adjuster pushbacks: "The existing chimney flashing is fine. We'll reuse it." This is wrong on almost every claim, and here's why.

Reason 1: You Can't Lift Shingles Without Disturbing Flashing

Step flashing is woven into the shingle courses. When shingles get torn off, the step flashing comes with them. You physically cannot remove the old roof without bending, tearing, or otherwise destroying the existing step flashing. Reusing it is not a viable option, even if you wanted to.

Reason 2: Counterflashing Is Often Sealed and Aged

Counterflashing that's been in place for 15 or 20 years is typically set in mortar or caulk that has degraded. Removing it cleanly enough to reuse almost never happens. And if the reglet is being recut (because the old one is compromised), the counterflashing must be replaced anyway.

Reason 3: Like-Kind-and-Quality Applies to Flashing

If the carrier is paying for a new roof, the flashing is part of that roof system. A new shingle roof over 20-year-old flashing is not like-kind-and-quality restoration. It's a compromised install that voids manufacturer warranties and sets up a future leak claim.

Reason 4: Manufacturer Specs Require New Flashing

Most shingle manufacturers explicitly require new flashing metal at all roof-to-wall and roof-to-chimney transitions as a condition of their warranty. GAF, CertainTeed, Owens Corning, and others publish this requirement in their installation instructions. An adjuster cannot override a manufacturer spec when writing a like-kind-and-quality estimate.

Supplement talking point: "Per GAF installation instructions and IRC R903.2, all flashing metal at roof-to-wall and roof-to-chimney transitions must be new when the roof is replaced. Reusing existing step flashing and counterflashing is not consistent with manufacturer warranty requirements or with like-kind-and-quality restoration standards."

Crickets Over 30 Inches (IRC R1003.20)

This is the single most commonly missed line item on chimney flashing supplements. IRC Section R1003.20 requires a cricket or saddle on any chimney more than 30 inches wide measured perpendicular to the roof slope.

Exact Code Language

The International Residential Code R1003.20 states that "Chimneys shall be provided with a cricket where the dimension parallel to the ridgeline is greater than 30 inches (762 mm) and does not intersect the ridgeline. The intersection of the cricket and the chimney shall be flashed."

Plain English Translation

If the chimney is wider than 30 inches on the upslope side, and it's not built into the ridge, a cricket is required by code. This is not optional. It is not a contractor preference. It is a code requirement that applies anywhere the IRC (or a state amendment of it) is adopted, which is most of the country.

What a Cricket Costs in a Real Estimate

A cricket is not a single Xactimate line item in most cases. It's a combination of framing lumber, sheathing, ice and water shield, shingles, and flashing. Build the cricket as a subassembly of its component parts when writing your supplement.

Real-world example: 44-inch-wide masonry chimney, no cricket on original install (common on older homes).

Cricket framing (2x4 and 2x6 lumber): $145

Cricket sheathing (1/2 inch OSB, 10 SF): $38

Ice and water shield underlayment: $62

Shingles over cricket (1 square minimum): $285

Valley metal at cricket-to-roof junction: $95

Subtotal: $625. Plus O&P at 20%: $125. Total cricket supplement: $750.

That's 750 dollars on a line item the adjuster didn't even include. On a roof with a large chimney, the cricket alone can be the biggest single supplement opportunity.

How to Measure and Scope the Chimney

Accurate measurements are what turn a supplement from a guess into a defensible request. Here's what to document on every chimney.

Field Measurements

• Chimney width (parallel to ridge): Measured in inches. Determines cricket requirement.
• Chimney depth (perpendicular to ridge): Measured in inches.
• Step flashing run (each side): Measured in LF from base of chimney to upslope corner.
• Base flashing width: Typically matches chimney width plus a few inches of overlap on each side.
• Counterflashing perimeter: Total LF around the three or four sides of the chimney that intersect the roof.

Photo Documentation

• Full chimney with roof in frame
• Close-up of each flashing component showing existing condition
• Mortar joints showing whether existing counterflashing is reglet-set or surface-mounted
• Upslope side of chimney with or without existing cricket
• Tape measure in frame for width measurements

When a supplement includes field-measured dimensions and photo documentation, the approval rate jumps dramatically. For more on building complete supplement documentation, see how to supplement a roofing claim.

Unit Pricing and Real-World Supplement Numbers

Here's what the individual components typically price at in 2026 Xactimate residential databases. Prices vary by region, but these ranges cover most markets.

Comparing Adjuster Line vs. Proper Scope

Adjuster wrote: R&R chimney flashing, 1 EA at $85. Total: $85.

Proper scope:

Step flashing, 16 LF x $10.50 = $168

Counterflashing, 14 LF x $15.50 = $217

Reglet cut, 14 LF x $11.00 = $154

Base flashing / front apron, 1 EA x $65 = $65

Cricket (44-inch chimney), full subassembly = $625

Subtotal: $1,229. Plus O&P at 20%: $246. Total: $1,475.

Supplement value: $1,475 minus $85 paid = $1,390 in missed scope on one chimney.

That's a single supplement opportunity on a single roof feature. Most homes with masonry chimneys have this same gap between what the adjuster wrote and what the scope actually requires.

Supplement Language That Cites IRC

Here's the exact template we see work on chimney flashing supplements. Adapt with your specific measurements and manufacturer references.

Supplement Request: Chimney Flashing Full R&R

The current estimate includes a single line for "R&R chimney flashing" at $85, which does not reflect the scope required to replace the chimney flashing system on this roof. The masonry chimney measures 44 inches wide by 26 inches deep and requires the following components:

1. Base flashing (front apron): 1 EA
2. Step flashing: 16 LF both sides combined (RFG FLASH)
3. Counterflashing: 14 LF around chimney perimeter (RFG CFLASH)
4. Reglet cut into mortar joints for counterflashing seating: 14 LF
5. Cricket / saddle on upslope face per IRC R1003.20 (chimney exceeds 30 inches in dimension parallel to ridge)

Per GAF installation instructions, all flashing metal at chimney-to-roof transitions must be replaced with new material when the roof is replaced. Existing step flashing cannot be salvaged due to its integration into shingle courses that are being removed.

IRC R1003.20 requires a cricket on any chimney wider than 30 inches measured parallel to the ridge. The subject chimney is 44 inches wide, triggering this requirement. A cricket is not present on the existing install and is required on the new install to achieve code compliance.

Requested additions are itemized above with supporting measurements, photos, and manufacturer spec attached. Please add to the claim with regional pricing plus O&P as applicable.

What Makes This Supplement Work

• Specific, field-measured dimensions
• Each Xactimate line item listed individually
• IRC code citation with exact section number
• Manufacturer spec reference
• Justification for why reuse is not possible
• Clean, professional tone with no argument or drama

For more examples of effective supplement language, see our Xactimate supplement list and how to read an Xactimate estimate guides.

Common Adjuster Objections and Responses

Here are the four objections you'll hear most often on chimney flashing supplements and how to respond to each.

Objection 1: "The Existing Flashing Was Fine"

Response: "The existing flashing was integrated into the shingle courses that are being replaced. Physically removing the roof requires disturbing the step flashing. Per manufacturer installation instructions, new flashing is required at all roof-to-wall and roof-to-chimney transitions when the shingles are replaced."

Objection 2: "The Cricket Wasn't There Before"

Response: "IRC R1003.20 requires a cricket on any chimney wider than 30 inches measured parallel to the ridgeline. The subject chimney measures [X] inches. Code compliance on the new install requires a cricket regardless of whether one was present on the original install. This is a code upgrade that falls under ordinance and law coverage if the policy includes it, and it is required scope in jurisdictions that have adopted the IRC."

Objection 3: "Your Counterflashing Price Is Too High"

Response: "The counterflashing line reflects regional Xactimate pricing for material and install, plus the reglet cut into mortar joints which is a separate labor item. Surface-mounted counterflashing is not warrantable under manufacturer specs and does not meet like-kind-and-quality standards when the original installation included reglet-cut counterflashing."

Objection 4: "We Can Write It as a Single Line Item"

Response: "The single line item RFG CHIM does not account for the individual components or the cricket. Writing each component separately is consistent with Xactimate scope standards for a residential chimney of this size and configuration. The supplemented itemization reflects actual scope and materials."

These responses work because they're grounded in code, manufacturer specs, and industry-standard practice. They aren't opinions or negotiation. They're documentation of what the install actually requires.

For a wider view on what other line items get missed on storm claims, see our line items adjusters miss roundup and the adjuster estimate review checklist.

Putting It All Together: Chimney Flashing Supplement Workflow

Here's the step-by-step process for supplementing chimney flashing correctly on every claim.

1. Measure the chimney. Width (parallel to ridge), depth, and step flashing run on each side.
2. Determine cricket requirement. If chimney is wider than 30 inches and doesn't intersect the ridge, cricket is required by IRC R1003.20.
3. Photograph existing condition. Include close-ups of each flashing component and mortar joints.
4. Check the estimate. Look for individual line items for base, step, counterflashing, reglet, and cricket. If they're compressed into a single generic line, flag it.
5. Write the supplement. Itemize each component with field measurements, manufacturer spec citations, and IRC code references.
6. Attach documentation. Photos, measurements, manufacturer spec pages, and code citations.
7. Track approval. If objections come back, use the scripted responses above.

Every home with a masonry chimney has meaningful supplement opportunity on the flashing scope. On smaller chimneys with no cricket requirement, the supplement may be 400 to 600 dollars. On larger chimneys with cricket requirements, it can easily exceed 1,500 dollars. Over a year of storm claims, that's real money left on the table every time the chimney gets glossed over with a single 85 dollar line item.

The claims that get fully paid are the claims that get fully documented. Chimney flashing is one of the clearest examples of why line-item-level review matters on every single estimate.