Mastering Roof Inspections: Asphalt Composition Shingles, Part 11

by Kenton Shepard and Nick Gromicko, CMI®



The purpose of the series “Mastering Roof Inspections” is to teach home inspectors, as well as insurance and roofing professionals, how to recognize proper and improper conditions while inspecting steep-slope, residential roofs. This series covers roof framing, roofing materials, the attic, and the conditions that affect the roofing materials and components, including wind and hail. 



Let’s move on to diagnosing problems with asphalt shingles.

Generally speaking, people from three different industries are likely to be inspecting asphalt shingles:  insurance claims adjusters; roofing contractors; and home inspectors.

Home inspectors are supposed to be neutral, third parties who have no financial interest in the conditions they find on the roof. Insurance companies and roofing contractors can both be affected financially by the results of the inspection, and they may have conflicting motivations.

Because of the many factors that can affect the condition of asphalt shingles, it’s not always clear whether a defective condition or functional damage exists. Conditions are not always obvious or either right or wrong.

Let's define the conditions that indicate functional damage or defective installation in asphalt shingles, as well as the criteria used during an inspection to determine whether functional damage exists.

Learning to diagnose roof conditions correctly will help those inspecting shingles to identify the source of the damage.  It will also make it easier for inspectors from different industries to come to the same conclusion when they’re each looking at the same condition.


Because inspections are so often connected with insurance claims, much of the criteria defined here is based on the standards of the insurance industry. Even if an inspection is for a sales transaction, if damage is found and the roof is under warranty, the transaction may be affected by an insurance claim.

For insurance purposes, “damage” is divided into two categories:  functional damage and cosmetic damage.

Functional Damage 

Functional damage is damage that insurance companies will pay for.  It’s also called covered damage or payable damage.

Functional damage is that which either diminishes the ability of the roof to shed water, or shortens its long-term service life. This is called “premature failure.”

Cosmetic Damage

Cosmetic issues are visual issues, such as discoloration, problems with color blending, or damage that doesn’t meet the definition of functional damage.  Some examples of cosmetic damage are general, uniform granule loss, or marring of the shingle surface.

With asphalt shingle roofs, insurance companies typically don’t pay for cosmetic damage.


Learn how to master a roof inspection from beginning to end by reading the entire InterNACHI series: Mastering Roof Inspections.

 Take InterNACHI’s free, online 
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