Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ROOFING INSPECTION & REPAIR
AMERICAN CEMWOOD ROOFING
BEST ROOFING PRACTICES
BUILT UP ROOFS
CATHEDRAL CEILING VENTILATION
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY FLASHING Mistakes & Leaks
COLD WEATHER ROOF TROUBLE
DECKS, ROOFTOP CONSTRUCTION
EPDM, RUBBER, PVC ROOFING
EXTRACTIVE BLEEDING on SHINGLES
FIRE RETARDANT PLYWOOD
FLASHING on BUILDINGS
FLAT ROOF MOISTURE & CONDENSATION
GREEENHOUSE / SOLARIUM ROOF LEAKS
HEAT TAPES & CABLES for ROOF ICE DAMS
ROOF ICE DAM LEAKS
MASONITE WOODRUF FIBERBOARD ROOFING
NOISE CONTROL for ROOFS
PLASTIC ROOFING TYPES
PVC, EPDM, RUBBER ROOFING
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF DORMER TYPES - PHOTO GUIDE
ROOF INSPECTION SAFETY & LIMITS
ROOF JOB PROBLEMS, RESOLVING
ROOF LEAK DIAGNOSIS & REPAIR
ROOF NOISE TRANSMISSION
ROOF REPLACEMENT SNAFUs
ROOFING FELT UNDERLAYMENT REQUIREMENTS
ROOFING MATERIALS, Age, Types
ROOFING TILE SHAPES & PROFILES
ROOFING UNDERLAYMENT BEST PRACTICES
SADDLE CONSTRUCTION at CHIMNEYS
SNOW GUARDS & SNOW BRAKES
STANDARDS for ROOFING
STRESS SKIN INSULATED PANELS
TEST LABS - ROOF SHINGLE
TREES & SHRUBS, TRIM OFF BUILDING
TRUSSES, FLOOR & ROOF
UNDERLAYMENT REQUIREMENTS on ROOFS
VENTILATION in BUILDINGS
WALK-ON ROOF SURFACES
WARRANTIES for ROOF SHINGLES
WORKMANSHIP & ROOF DAMAGE
Cupping asphalt shingles: this article series describes cupped asphalt roofing shingles and how to identify & explain the most-common asphalt roof shingle failures. These cupping shingle defects occur on both organic-mat and fiberglass-mat asphalt roof shingles, but are more common on organic mat asphalt shingle roofs.
We describe the difference between shingle cupping & shingle curling - which can be important in diagnosing the cause of early roof wear or damage. And we warn against walking on cupped shingle roofs. Readers are also invited contribute roof failure information to the web author for research purposes. web author for research purposes.
Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.
Definition of Asphalt Shingle Cupping
Cupping asphalt roof shingles, particularly on organic or felt-based asphalt shingles, are a normal wear pattern that shows up with shingle age.
Cupped asphalt shingles are show in our page top photo and in others on this page. In our photo (left) the top arrow in the photo at left points to the left side of a "cupped" area of this roof shingle. The shingle edges are also curled in these photos, which is part of this wear pattern.
This "normal" cupping or curling pattern will display shingles which are concave in their center, with the corners and possibly the three exposed shingle tab edges curled such that the very edge of the shingle curls downwards.
Definition of Asphalt Shingle Clawing
"Clawing" is also used to describe the appearance of asphalt roof shingle corners that curl down and under (photos above and below). Marshall et als (1999) observed:
Common Asphalt Shingle Wear Indicators are often combined on a single roof
Our photo (left) shows that on the right-hand roof, virtually all of the shingles are cupped (red arrows & lines) and the shingles are also fish-mouthed. The staggering of fish mouthing on the roof is consistent with the location of shingle butt joints in successive courses.
Asphalt roof shingles as they wear either normally or in some cases at an accelerated (early failure) rate, often show one of the following wear signs, but as our photo at left illustrates (both cupping & curling) shingles can show any or all of these wear signs in combination as well.
Each of these asphalt roof shingle conditions is different in appearance and while all of them may indicate worn, old, or fragile roof coverings, their causes and prevention vary. In some of the photos of cupped roof shingles on this page, "fishmouthing" is also visible (see photo at page top). It is common for multiple wear signs to be present at once.
As you can see in our photo (left) the raised fishmouth section of the cupped shingles is already cracking on its own. Stepping on this raised point (blue arrow) or on the raised area of the cupped shingle (red arrow) is likely to break it, converting a worn-out roof into one that is actively leaking.
If we absolutely have to walk on such a roof, we would tiptoe carefully, avoiding stepping on the raised or cupped shingle sections, or if doing repairs, we would 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.
Walking on a cupped shingle roof can cause irreparable damage: Take this warning seriously: an old cupped asphalt shingle roof may not yet be leaking and could last several more years depending on its condition.
But we have seen cupped asphalt shingle roofs that had been destroyed by the "inspector" who walked all over the roof, breaking shingles everywhere he stepped, leaving a trail of damage and leading to the need for an immediate roof replacement. The roof would have needed replacement soon before the "inspection."
After the "inspection" the roof needed immediate replacement. we could actually see the "footprints of destruction" across the roof surface.
Research Citations for Asphalt Shingle Cupping & Clawing
Continue reading at CURLING ASPHALT SHINGLES or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs) about cupping asphalt roof shingles
Question: why are shingles on my new roof cupping ?
Why is my new Roof cupping and it is only 2 weeks old? Yes Two weeks? - Joyce 11/28/11
Cupping of brand new roof shingles would be unusual. It might occur if shingles were installed over a wet roof deck or over an old layer of cupped, curled, or wet roof shingles.
Question: My 25-year warrant asphalt shingles are cupping after 13 years
I have a situation where my asphalt shingles have a 25 year material warranty and were installed 13 years ago. A large portion of the shingles are now cupping. The roof is a very simple hip roof with a single gable and one valley. Why are the shingles failing at approximately half of their life? Should the shingle manufacturer be held liable for the early product failure? Will they actually honor this material warranty? - Scott S. 3/12/12
Scott, shingle warranty claims are honored by manufacturers based in part on the manufacturer's assessment of the nature of the problem and their determination of whether the problem is due to faulty product or due to other problems such as a faulty installation or a structural or roof venting problem. You will want to contact the manufacturer and ask them to take a look at the roof, and
Questions & answers or comments about shingle cupping: causes, remedy, types of roofs where cupping asphalt shingles are most often found, impact on remaining roof life.
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References