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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.


• 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


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


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


Roof (turtle) vent Flue vent cap


Clean marks on algae-stained shingles


Fractures in plastic gutter guards

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


Intentional (“Hail”) Damage

Blemishes created in an attempt

to mimic hail damage

Intentional Damage – Study #1


Let’s go to the film…


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 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


Wind Damage (3-tab)

Wind Damage (Dimensional)

Intentional (“Wind”) Damage

Shingles removed or creased in an

attempt to mimic wind damage

Intentional (“Wind”) Damage

Delamination of shingles due to the

sealant strip being pulled apart

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.


Office: 800-482-5611 Ext: 2108

Mobile: 704-477-7125

www.donan.com

wind, hail, and intentional - verisk analytics | better ... · shingles, and the installation...

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