Fishmouthed roof shingle fail(C) Daniel Friedman Causes & Types of Asphalt Shingle Roof Failures

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Asphalt roof shingle failure guilde:

This article series tells readers how to identify & explain the most-common asphalt roof shingle failures and how to obtain asphalt roofing shingle failure claims assistance.

Common asphalt shingle failure factors include improper storage and handling of the asphalt shingles before installation, improper nailing, improper flashing (which pertains to any roofing material), and defective asphalt shingle product material leading to thermal splitting, cracking, blistering, staining, and in some cases curling or cupping shingles.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

What are the Types of Failures That Occur on Asphalt Shingle Roofs?

Shingle cracks in cutouts (C) Daniel Friedman

Storm damage from wind and hail occur and need to be distinguished from defective asphalt shingle product or asphalt shingle installation errors.

Cupping and curling due to age can be distinguished from "fishmouthing" (shown in the photo above) caused by inadequate attic venting and building moisture.

Readers are also invited contribute roof failure information to the web author for research purposes. See the page top or bottom CONTACT link.

In general, roof "failures" or complaints separate first into these general categories:

  1. Cosmetic roof covering complaints, such as shadow lines, superficial blistering (maybe becomes a wear issue), uneven surfaces, improper randomizing of shingle bundles leading to color patches on the roof.


  2. Functional roof covering defects that result in active leaks or an anticipated reduction in the life of the roof shingles compared with the shingle warranty period or shingle life anticipated by the manufacturer.

    Keep in mind that the life of any roofing product on a particular building is greatly influenced by factors beyond the material itself, such as
    • Correct roof product installation according to the manufacturer's instructions and roofing industry standards for roof deck preparation, underlayment, placement, nailing, flashing, and even wear from traffic on the roof during and after installation.
    • Roof slope, color, and orientation to sun and weather
    • Effects of nearby trees
    • See ASPHALT SHINGLE LIFE / WEAR FACTORS for our complete list of factors that affect the life of a roof

Photo Guide to the Differences Among Asphalt Shingle Cupping, Curling, & Fishmouthing

Are these shingles curled, cupped, fishmouthed, or a combination of all three? By my [DF] definitions of these shingle failure and wear patterns, the shingles below are curled - the tab corners are "up". Indeed viewed obliquely (below right) one might mistake this for a "fishmouth" pattern but it's not.

Below our asphalt shingle roof damage photos illustrate types of shingle damage or wear in this order: cupped shingles, curled shingles, fishmouthed shingles.

Cupped roof shingles (C) Daniel Friedman Fishmouthed roof shingle fail(C) Daniel Friedman Fishmouthed roof shingles (C) Daniel Friedman

[Click to enlarge any image]

Watch out: as you can see at our third photo at above right, these defects may occur together on a roof. To the right of the chimney we see fishmouthing as well as some shingle cupping. Surely this is a fragile roof. Stay off.

Question: My Cracked Roof Shingles are a Product Defect but No One Told Me When I Was Buying the House

Asphalt shingle thermal splitting (C) Daniel Friedman

I am having a roofing issue and would love your opinion/suggestions on how to proceed.

I purchased a home in Jan. of 2010. The home was inspected by a licensed inspector prior to the purchase.

I recently had a roofing contractor come out to look at an issue I have with some siding. From the ground, the roofer noticed that the shingles were part of the GAF class action lawsuit from 1999. He got up on the roof and confirmed his suspicions. He also took photos of cracked and damaged shingles.

[Our photo at left of thermal splitting on an asphalt shingle roof is an example but it is not the very roof discussed in this question - DF]

I got some information about the roof from my realtor. The roof was replaced in the early part of 1999 with those GAF shingles. The house was sold in December of 1999.

I'm thinking that the class action/recall information never made it to the new owners or they chose to ignore it. Either way, we have a badly damaged roof, our inspector failed to note any of it, and 11+ years have passed since the class action lawsuit.

I am in the process of trying to file a claim with GAF, but I'm afraid that at best, I'll get a pro-rated amount (obviously just a fraction of an entire new roof).

My question is: do I have any recourse against the previous homeowner? the inspector?

I'm at a loss, so any ideas would be very helpful. Thanks very much - J.M.

Reply: How Do We Decide If a Home Defect Should Have Been (Could have Been) Disclosed?

Thermal splitting asphalt shingle (C) Daniel Friedman

First, you should obtain an accurate assessment of the roof condition, it's estimated remaining life, and whether or not the damage you report is significant - in writing, by a neutral professional.

At CRACKS in FIBERGLASS SHINGLES we discuss asphalt shingle cracking and product failures that indeed were known to be happening around the time you bought the home.

While we still see an occasional asphalt shingle roof with thermal splitting (the cracks in the article we cite above), most of those roofs have been replaced by now.

If when you bought your home in 2010 its roof was covered by asphalt shingles that were 15 years or so old, and more if the shingles were visibly cracked or damaged, the inspector might have warned you that there was little or no reliable roof life remaining, independent of the product failure question.

You might have legal recourse over a home inspection adequacy or an owner or realtor disclosure issue, but that's a legal question to take to an attorney familiar with real estate law.

The attorney will want to review your contracts and any other documents presented at the time you purchased the home.

In our OPINION, IF there was visible evidence of a significant defect or dangerous condition at the time of your home inspection, the inspector should have told you about it.

Shingle cracks in cutouts (C) Daniel Friedman

Watch out: if conditions prevented the home inspector from direct access onto the roof or at least a look from a ladder set against the roof edge, shingle damage, cracks, and splits such as that shown in own photo (above left) could have been difficult or even impossible to spot. Inspecting the roof from the ground, even with good binoculars, can't show all roof damage types and conditions.

And keep in mind that there are good reasons that an inspector is never required to walk on a roof surface, such as accessibility, safety hazards and/or fragile roof conditions.

The asphalt shingle crack shown at left is located in the upper portion of an asphalt roof shingle, visible at the cutout between shingle tabs of the shingle course overlaying the split shingle. This crack would be just about impossible to see without a very careful on-roof inspection.

Additional on-roof photos of some hard-to-see shingle cracking problems are


In our OPINON, if you can show that the prior seller knew about the condition, s/he may have been obligated by real estate fraud law to tell you about it; though in some states the seller can pay a modest fee - in NY it's $500 - in exchange for being allowed to disclaim any representations about the condition of the home at the time of purchase.

So particularly when such a disclaimer is going to be made, a thorough home inspection by a competent home inspector, and by one who has absolutely no conflicts of interest, is essential to protect both buyer and seller from a future dispute.

More examples of types of roof shingle wear or damage are

at ASPHALT SHINGLE LIFE / WEAR FACTORS and still further examples will be found in the More Reading list below see the ARTICLE INDEX where we list detailed articles describing just about every type of asphalt shingle roof failure.


Continue reading at ASPHALT SHINGLE INSTALLATION or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.



Or see ASPHALT ROOF SHINGLES - home, for all articles about asphalt roof shingles

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