Asphalt Shingle Curling - Signs of Shingle Wear

  • CURLING ASPHALT SHINGLES - CONTENTS: Asphalt roof shingle curling photographs & explanation. Curled shingle edges Curled asphalt shingle corners, Diagnosing the causes of early asphalt shingle roof failure: curling, granule loss. Types & photographs of organic felt asphalt roof shingle defects & failures
  • POST a QUESTION or READ FAQs about curling asphalt roof shingles: causes & cures
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Curling asphalt shingle roofs:

This article describes shingle curling as a sign of wear on asphalt shingle roofs and discusses how to identify & explain the most-common asphalt roof shingle failures. We illustrate different asphalt shingle curling patterns, types & causes, and we discuss how to decide if a curling-shingle roof can be repaired or if it needs replacement.

We also illustrate early roof shingle failure on a 6-year old installation. Our page top photo shows shingle edge down-curling. Other photos on this page show shingle corner curling.

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Curling Asphalt Shingle Explanation & Photos

Curled, worn-out organic asphalt roof shingles

Shingle curling defects occur on both organic-mat or fiberglass-mat asphalt roof shingles, though we see them more often on organic-mat shingles.

Curling roof shingles (as shown here) will show a curling-under at the edges of the shingle tab, first at the lower edge and sometimes also at the two sides of the shingle tab. The page top photograph of curled roof shingles shows a worn-out roof that needs replacement as soon as possible.

[Click to enlarge any image]

Making the distinction between "curled" roof shingles as shown on this page and "cupped" roof shingles as shown on the previous page may be a bit of a nuance of mostly academic interest since both conditions are signs of an older, worn roof.

But we have found that stepping on and breaking the edge of a curled roof shingle might cause less damage than that caused by walking on a cupped shingle roof where larger pieces of shingle break off under the feet of a thoughtless "roof inspector".

In fact we have seen a "failed" roof that was not leaking until the fellow who was asked to inspect it walked across this fragile surface.

From a ladder at the roof edge one could clearly see the virtual footprints of broken shingle edges where the "inspector" had walked. It's best to stay off fragile roof surfaces to avoid converting a "near end of life" condition to a "failed, leaking" condition.

Curling and cupping may occur together on the same roof, or shingles may appear to be curled-only (or fishmouth-curled-only as you'll read next). We don't see cupping without some curling.

Fishmouthed roof shingle fail(C) Daniel Friedman

As we advised about cupped roof shingles, when inspecting a a curled-shingle roof we would also be careful to stay off of it, particularly in cold weather since as with cupped or fish mouthed shingles they are more likely to break when stiff and cold.

And as we said earlier, if you have to walk on such a roof, move carefully, avoiding stepping on the raised or cupped shingle sections.

The badly curled, failing asphalt shingle roof shown at left was observed on a home in Arizona - certainly not a freezing climate, but nonetheless, walking on this roof will only cause further damage. These shingles are worn out and need replacement. [Click any InspectApedia image to see an enlarged version.]

It is rare that it's cost justified to repair a badly curled-shingle roof, but if it's absolutely necessary, perhaps as a stopgap measure while waiting for a whole new roof, when making curled shingle roof repairs, either work from adjacent surfaces which are in better condition, work your way down the roof from damaged areas back to the ladder, or prop a ladder up off of the roof surface and work from that scaffold as is sometimes done with slate or other fragile roof surface repairs.

Six Year Old Roof Shingle Curling & Granule Loss Diagnosis & Commentary

Fishmouthed roof shingle fail(C) Daniel Friedman

Question about early asphalt roof shingle failure:

Fishmouthed roof shingle fail(C) Daniel Friedman

I live in Wisconsin and had my roof replaced (total strip down) about 6 years ago. Now my shingles are curling up or fish mouthing. I do not know what you call it but it looks terrible . Can you help me out? A friend said to check on the internet for something with Owens Corning.

I believe they are 30 yr shingles. I do not have any of the paper work but when they put them on they said they only use premium shingles. Check out the rain gutter. It is 3/4 full of shingle fragments and granules. The rest of the roof shingles still look good. Any help would be great. - Louis Tolley, Adams WI

Fishmouthed roof shingle fail(C) Daniel Friedman

Answer and advice on diagnosing a failing fishmouthed shingle "new roof" job:

Fishmouthed roof shingle fail(C) Daniel Friedman

The roof shingle wear pattern in your photos is easily mistaken for "fishmouthing asphalt roof shingle" but what we see in your photos is not "fishmouthing" but rather shingle curling, combined with extreme granule loss.

The definitions of shingle cupping, curling, and fishmouhing are given at ASPHALT SHINGLE FAILURE TYPES where we include photos of each of those wear patterns. It's worth getting the terms correct if for no other reason than to waste time arguing about the condition of a roof and its remaining life. More, while shingle curling and cupping are normal wear patterns on older asphalt shingle roofs, in some patterns, and certainly in the fishmouth pattern, there is a suggestion of an underlying moisture or roof venting problem that needs attention.

Comparing Shingle Fishmouth Patterns with Shingle Curling Patterns

Fishmouthing asphalt shingles appear as an upwards curve in the center of shingle tabs, usually where the center of a fishmouthed shingle tab crosses over the shingle butt joints in the course below. See the fishmouth shingle photos above on this page.

Shingle tab curling, such as shown in your photos, occurs at the corners of shingle tabs, not in the center of the tab. See CURLING ASPHALT SHINGLES.

How old is This Roof Wear-Out?

Regardless, your roof photos show severe wear and curled shingle tabs that we see at the end of roof life - your photos of this worn roof slope show that every single shingle tab is curled up from a corner – that combined with the significant granule loss would be very unusual on a six-year-old roof. We comment further and provide some roof failure diagnostic questions just below.

From looking at the photographs, and recognizing that we are not looking at the entire roof, some comments and questions arise that should help sort out this "early roof failure" mystery:

Fishmouthed roof shingle fail(C) Daniel Friedman

Fishmouthed roof shingle fail(C) Daniel Friedman

Six-Year-Old Roof Shingle Failure Diagnostic Questions

Watch out: First off - don't fall off the roof while you are up there looking around.

Don't walk on these fragile, damaged asphalt shingles - they'll break and leak.

Go back to look at your information on your 6 year old re-roof job with the questions listed below. If you have no records and no documentation of who did the roof, what was the contracted scope of work (all slopes or just some) we can still figure this out by inspection of the whole building.

Usually when we have inspected early roof failure cases like this it turns out that there was a misunderstanding (or less often, dishonesty) - the roofer did not re-shingle all slopes, maybe just one of them, but the owner thought they all were being done.

Also see our shingle curling photos and comparison with shingle fishmouthing shown at EARLY ROOF FAILURE DIAGNOSTIC QUESTIONS [live link given just below].


Continue reading at EARLY ROOF FAILURE DIAGNOSTIC QUESTIONS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


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