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Wind, Hail, and Intentional
Damages to Asphalt Shingles
Presented by:
Michael D. Spensieri, P.E.
Regional Engineering Manager
Office: 800-482-5611, Ext: 2108
www.donan.com
Introduction
A thorough site inspection is vital to
properly evaluating wind and hail
damage after an event. Recognizing the
telltale indicators and knowing how to
assess conditions will help distinguish
between storm-related, non-storm-
related, and intentional damages.
Presenter
Michael D. Spensieri, P.E.
Regional Engineering Manager
• 18 years of experience in the construction, home
building and forensic engineering fields
• Managed multiple CAT event responses for DONAN
• DONAN CAT Program Team Member
• Licensed P.E. in 16 states
• B.S.C.E from West Virginia University
Goals
• Open environment
• Interactive discussion…PLEASE ask questions
• Let’s share knowledge on wind, hail…and
intentional damages!
Outline
• Information on asphalt shingles
• General hail information
• Hail inspections with case studies
• General wind information
• Wind inspections with case studies
• Four out of five homes (80%) are roofed with
asphalt shingles!!!
• Over 12 billion square feet of asphalt shingle
products are manufactured annually.
– Enough to cover 5 million homes
– Enough to cover ½ of Rhode Island
Shingle Information
Shingle Life Expectancy
The life expectancy of asphalt shingles is
determined by three factors:
• The slope of the roof
• The color of the roof
• Exposure to the sun
Shingle Life Expectancy
As a Rule of Thumb (fiberglass-mat only):
• IF asphalt shingles are properly installed on a well-ventilated roof with
only one layer of shingles, on average they typically have life
expectancies of 85-percent of the amount offered by their
manufacturer’s limited warranty.
• Additional depreciation expected for warranty durations beyond 30 years
Shingle Warranty Average Life Expectancy1
20 years ~18 years
25 years ~21 years
30 years ~25 years
40 years ~33 years
Lifetime ~40 years1 Not a scientifically verified average, but is based on Donan Engineering Company’s study of thousands of asphalt shingle residential roofs.
Let’s talk about hail
Damaging Hail
Source: www.nachi.org
• “Neighboritis syndrome” or “roof envy”
• Contractor-driven, door-to-door solicitations
• “My contractor said…(fill in the blank)”
Why do so many people incorrectly
believe their roof has hail damage?
General Hail Info
• A transfer of energy takes place
• Angle of impact plays a large role
• Softer the material, more energy is absorbed
• Underlying support of the object being struck
Hailstone Formation
Source: www.nachi.org
Hailstone EnergyHail Fall-Speed Table
(Greenfield, 1969)
1 Foot-pound: The energy transferred by applying a force of one pound through a displacement of one foot.
Hailstone Energy
Hailstone Size to Cause Damage
Roofing Material Hail Size (diameter)
3-tab organic shingles ¾ to 1-inch
Thermoplastic Covering (TPO) 1-inch
3-tab fiberglass shingles 1 to 1¼-inch
cedar shingles 1¼-inch
fiber-cement tiles 1¼-inch
flat-concrete tiles 1¼-inch
heavy cedar shakes 1¼-inch
30-year dimensional/laminated shingles 1¼ to 1½-inch
Built-up Roof (smooth surface) 1½-inch
Built-up Roof (gravel covered) 2-inch
Modified Bitumen 2-inch
S-shaped concrete tiles 2-inch
EPDM 2½ to 3-inch
Source: www.nachi.org
Hail Site Inspections
Site Study Inspection
• On-site collateral indicators
• On the roof
Collateral Indicators
Collateral indicators of hail impact are
extremely important in any hail study as they
provide clear and tangible clues about the
nature of the hailstorm:
• Size
• Direction
• Density
Collateral Indicators
Roof (turtle) vent Flue vent cap
Collateral Indicators
Clean marks on algae-stained shingles
Collateral Indicators
Source: www.nachi.org
Collateral Indicators
Fractures in plastic gutter guards
Collateral Indicators
Source: www.nachi.org
Roof Inspection
Susceptible Shingles:
• Shingles that face incoming hailstones
• Shingles that are less firmly supported
– Examples???
Roof Diagram
What is hail damage?
What is hail damage?
Hail damage to asphalt shingles is defined as an
identifiable mark of distress caused by hail that
has measurably and significantly reduced the
integrity and/or functionality of the overall
shingle, where the shingle was sound prior to the
hail impact. Hail damage is sometimes found in
the form of: mat fracture; a deflection (bruise);
and/or significant granule loss exposing the
shingle asphalt layer.
Hail Strikes:
What do they look like?
Hail Damage
Source: www.nachi.org
Hail Damage
Hail Damage
Hail Damage
Intentional (“Hail”) Damage
Blemishes created in an attempt
to mimic hail damage
Intentional (“Hail”) Damage
Source: www.nachi.org
Intentional Damage – Study #1
Intentional Damage – Study #1
Intentional (“Hail”) Damage
Source: www.nachi.org
Intentional (“Hail”) Damage
Source: www.nachi.org
Intentional (“Hail”) Damage
Source: www.nachi.org
Intentional Damage – Study #2
Intentional Damage – Study #2
Intentional Damage – Study #2
Intentional Damage – Study #2
Let’s go to the film…
Intentional Damage – Study #2
Intentional Damage – Study #2
What’s better than catching someone red handed???
Other Blemishes & Issues
• Moss and lichen growth/damage
• Bird damage
• Heat blistering
• Nail pops
• Inadvertent man-made damage
• Granules in the gutters
Let’s review hail damage...
10 things to consider…
1. Hail storms have predominant direction
2. Hail sizes vary up to the largest stone
3. Hail fall strikes entire property
4. Hail damages most susceptible components easily
5. Hail does not scratch or gouge factory applied metal paint coatings
6. Hail fall is not afraid of steep slopes or roof edges
7. Hail falls in random global pattern
8. Hail falls in random local pattern
9. Hail does not crush granules
10.Hail does not gouge asphalt
WIND
Wind Information
• Wind damage can take several different forms depending on
the wind strength, building orientation, condition of the
shingles, and the installation method.
• Wind damage to three-tab shingles occurs when individual
shingle tabs (of three-tab shingles) are lifted and bent. For
wind damage to be present, the shingle must be missing,
torn, or creased.
• Dimensional shingles are much more resilient to bending
damage than three-tab shingles due to the added stiffness
provided by the second (laminate) layer of the shingle.
Wind Information
• Dimensional shingles are often completely blown from the
roof instead of suffering bending damage.
• Damage most commonly occurs along the edges of the roof’s
surface, or on leeward edges of hips and ridges, where the
uplift pressures are the greatest.
• Failed sealant strips are common on roofs and can occur due
to a variety of causes.
• Many contractors insist that unsealed shingles or tabs are
the result of wind uplift. …they are not.
Wind Information
Source: www.nachi.org
Wind Damage (3-tab)
Wind Damage (3-tab)
Wind Damage (3-tab)
Wind Damage (Dimensional)
Wind Damage (Dimensional)
Intentional (“Wind”) Damage
Shingles removed or creased in an
attempt to mimic wind damage
Intentional Damage – Study #3
Intentional Damage – Study #3
Intentional Damage – Study #3
Intentional Damage – Study #3
Intentional Damage – Study #3
Intentional (“Wind”) Damage
Delamination of shingles due to the
sealant strip being pulled apart
Intentional Damage – Study #4
Intentional Damage – Study #4
Intentional Damage – Study #4
Intentional Damage – Study #4
Intentional Damage – Study #5
Intentional Damage – Study #5
Intentional Damage – Study #5
Intentional Damage – Study #5
Other Blemishes & Issues
• Unsealed shingles due to the vertical racking
• Manufacturer’s defects
• Crazing
• Inadvertent man-made damage
Closing…with the intro
A thorough site inspection is vital to
properly evaluating wind and hail
damage after an event. Recognizing the
telltale indicators and knowing how to
assess conditions will help distinguish
between storm-related, non-storm-
related, and intentional damages.
Questions???
Source: ibtimes.com
Thank you!!!Michael D. Spensieri, P.E.
Regional Engineering Manager
Office: 800-482-5611 Ext: 2108
Mobile: 704-477-7125
www.donan.com
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