Flashing repair and resealing: what it is and when you need it
Updated Sep 2026·National·Repair — metal & components
What is chimney flashing repair?
Flashing repair reseals or replaces the metal that seals the joint where a chimney comes through the roof. That metal is step flashing up the sides, counter-flashing let into the mortar joints, and sealant along the top edge. The work runs from resealing a counter-flashing line to cutting in new metal.
Tar smeared over old flashing is a patch, not a repair, and it fails.
When is it actually needed?
When water appears at the chimney in ordinary rain, when the metal is lifted, split or rusted, and whenever the roof is replaced.
What standard does it answer to?
NATIONAL · IRCNATIONAL · MANUFACTURER INSTRUCTIONS
- The International Residential Code (IRC) — the model building code for one- and two-family homes, adopted and often amended state by state and city by city.
- The manufacturer's installation and service instructions — for a listed appliance or component, they are the specification it was tested to.
What should the invoice or report show?
Ask whether new counter-flashing is being cut into the joint or the old one resealed, and who warrants the roof afterwards.
What does it cost?
- Low
- $300
- Median
- $600
- High
- $1,600
- Unit
- per job
How we researched this · 3 sources
Low, median and high are drawn from 3 published sources (2 published cost guides, 1 company price page), checked Jul 2026. This is a national range, not a quote and not data from listings on this site. Region, roof pitch, access and what an inspection finds all move the real price.
Does your state regulate this?
The IRC is a national model document, not state law: which edition applies to your home, if any, depends on the codes your state and city have adopted. Manufacturer instructions travel with the product: they set its requirements wherever it is installed, separately from the building code. Few jurisdictions name chimney or hearth work in a credential at all; the rule that usually touches a job like this is about the company — a general contractor or home-improvement license or registration where the state has one, sometimes only above a dollar threshold. Our 50-state laws table and licensing by state set out what each state requires.
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Questions about chimney flashing repair
When is chimney flashing repair needed?
When water appears at the chimney in ordinary rain, when the metal is lifted, split or rusted, and whenever the roof is replaced. The work answers to the IRC and the manufacturer's instructions.
Is chimney flashing repair regulated by state law?
The IRC is a national model document, not state law: which edition applies to your home, if any, depends on the codes your state and city have adopted. Manufacturer instructions travel with the product: they set its requirements wherever it is installed, separately from the building code. Few jurisdictions name chimney or hearth work in a credential at all; the rule that usually touches a job like this is about the company — a general contractor or home-improvement license or registration where the state has one, sometimes only above a dollar threshold. Our 50-state laws table and licensing by state set out what each state requires.
What should I ask before agreeing to chimney flashing repair?
Ask whether new counter-flashing is being cut into the joint or the old one resealed, and who warrants the roof afterwards.