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This website 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. Our page top photo shows shingle edge down-curling. Other photos on this page show shingle corner curling.
Also see our shingle curling photos and comparison with shingle fishmouthing shown at EARLY ROOF FAILURE DIAGNOSTIC QUESTIONS. These shingle curling defects occur on organic-mat or fiberglass-mat
asphalt roof shingles. Readers are also invited contribute roof failure information to the web author for research purposes.
web author for research purposes.
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.
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.
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.
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
Question about early asphalt roof shingle failure:
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
Answer and advice on diagnosing a failing fishmouthed shingle "new roof" job:
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.
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:
The roof slopes in your photographs are totally worn out
This does not look like a six year old roof
Your comments suggest that other roof slopes are fine.
Before we assume that the wear difference is due to the building, roof ventilation, weather exposure, or a similar cause, let's conside that the roof is reported to be just six years old - actually we wonder if that's quite right.
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.
What type of shingles were installed in your re-roof job six years ago (your photos of failing shingles look like organic base not fiberglass base)
Are the same type of shingles present on all roof slopes?
Were all the roof slopes re-roofed or just some slopes? Sometimes only the worst or actively leaking roof slope is replaced, especially if the homeowner is squeezing for the lowest re-roof price, money is tight, or the roofer feels that there are five or more years remaining on other roof slopes
Did anyone actually inspect the roof before and after the job, other than the roofer?
Do all of your roof slopes look the same? That is, is the shingle wear the same on all slopes?
Are all roof slopes exposed to similar wind and weather conditions ? Usually not - which slope(s) show the most shingle wear?
Are you sure the roofer actually replaced shingles on all of the slopes?
Did you actually see that work being done?
If you remove or lift one of these bad shingles at the roof edge, do you see raw roof deck below or other old shingle layers?
Other asphalt shingle roof wear indicators and conditions (besides fishmouthing) are discussed beginning at ASPHALT ROOF SHINGLES.
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.
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Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. (727) 595-4211 mark@BestTampaInspector.com
Hankey and Brown home inspectors, Eden Prairie, MN, technical review by Roger Hankey, prior chairman, Standards Committee, American Society of Home Inspectors - ASHI. 952 829-0044 - hankeyandbrown.com
Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Architectural elements: the technological revolution: Galvanized iron roof plates and corrugated sheets; cast iron facades, columns, door and window caps, ... (American historical catalog collection), Diana S Waite, available used out of Amazon.
Green Roof Plants: A Resource and Planting Guide, Edmund C. Snodgrass, Lucie L. Snodgrass, Timber Press, Incorporated, 2006, ISBN-10: 0881927872, ISBN-13: 978-0881927870. The text covers moisture needs, heat tolerance, hardiness, bloom color, foliage characteristics, and height of 350 species and cultivars.
Green Roof Construction and Maintenance, Kelley Luckett, McGraw-Hill Professional, 2009, ISBN-10: 007160880X, ISBN-13: 978-0071608800, quoting: Key questions to ask at each stage of the green building process Tested tips and techniques for successful structural design
Construction methods for new and existing buildings
Information on insulation, drainage, detailing, irrigation, and plant selection
Details on optimal soil formulation
Illustrations featuring various stages of construction
Best practices for green roof maintenance
A survey of environmental benefits, including evapo-transpiration, storm-water management, habitat restoration, and improvement of air quality
Tips on the LEED design and certification process
Considerations for assessing return on investment
Color photographs of successfully installed green roofs
Useful checklists, tables, and charts
Problems in Roofing Design, B. Harrison McCampbell, Butterworth Heineman, 1991 ISBN 0-7506-9162-X (available used)
Roofing The Right Way, Steven Bolt, McGraw-Hill Professional; 3rd Ed (1996), ISBN-10: 0070066507, ISBN-13: 978-0070066502
Slate Roofs, National Slate Association, 1926, reprinted 1977
by Vermont Structural Slate Co., Inc., Fair Haven, VT 05743, 802-265-4933/34. (We recommend this book if you can find it. It
has gone in and out of print on occasion.)
Roof Tiling & Slating, a Practical Guide, Kevin Taylor, Crowood Press (2008), ISBN 978-1847970237, If you have never fixed a roof tile or slate before but have wondered how to go about repairing or replacing them, then this is the book for you. Many of the technical books about roof tiling and slating are rather vague and conveniently ignore some of the trickier problems and how they can be resolved. In Roof Tiling and Slating, the author rejects this cautious approach. Kevin Taylor uses both his extensive knowledge of the trade and his ability to explain the subject in easily understandable terms, to demonstrate how to carry out the work safely to a high standard, using tried and tested methods.
This clay roof tile guide considers the various types of tiles, slates, and roofing materials on the market as well as their uses, how to estimate the required quantities, and where to buy them. It also discusses how to check and assess a roof and how to identify and rectify problems; describes how to efficiently "set out" roofs from small, simple jobs to larger and more complicated projects, thus making the work quicker, simpler, and neater; examines the correct and the incorrect ways of installing background materials such as underlay, battens, and valley liners; explains how to install interlocking tiles, plain tiles, and artificial and natural slates; covers both modern and traditional methods and skills, including cutting materials by hand without the assistance of power tools; and provides invaluable guidance on repairs and maintenance issues, and highlights common mistakes and how they can be avoided.
The author, Kevin Taylor, works for the National Federation of Roofing Contractors as a technical manager presenting technical advice and providing education and training for young roofers.
The Slate Roof Bible, Joseph Jenkins, www.jenkinsslate.com,
143 Forest Lane, PO Box 607, Grove City, PA 16127 - 866-641-7141 (We recommend this book).
Solar heating, radiative cooling and thermal movement: Their effects on built-up roofing (United States. National Bureau of Standards. Technical note), William C Cullen, Superintendent of Documents, U.S. Govt. Print. Off (1963), ASIN: B0007FTV2Q
"Weather-Resistive Barriers [copy on file as /interiors/Weather_Resistant_Barriers_DOE.pdf ] - ", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
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