In addition to covering defects from manufacturing, installation, and natural weathering, the articles also cover the accurate identification of wind and hail damage.

Although these articles were written primarily for home inspectors, the criteria used to evaluate roofs is also relevant for insurance and roofing industry professionals -- both of whom we worked with closely in developing this series -- to determine functional versus cosmetic damage, and whether damage was caused by wind, hail, weathering, improper installation, or manufacturing defects.

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Article Index for

Mastering Roof Inspections

Roof Styles

Mastering Roof Inspections: Roof Styles

Roof Framing

Mastering Roof Inspections: Roof Framing, Part 1

Accessing the Roof

Mastering Roof Inspections: Accessing the Roof, Part 1

Mastering Roof Inspections: Accessing the Roof, Part 2

Mastering Roof Inspections: Accessing the Roof, Part 3

Mastering Roof Inspections: Accessing the Roof, Part 4

Mastering Roof Inspections: Accessing the Roof, Part 5

ASPHALT SHINGLE COMPONENTS

Mastering Roof Inspections: Asphalt Composition Shingles, Part 1

ORGANIC SHINGLES

Mastering Roof Inspections: Asphalt Composition Shingles, Part 2

Asphalt Composition

Mastering Roof Inspections: Asphalt Composition Shingles, Part 3

Back-Surfacing

Granules

Mastering Roof Inspections: Asphalt Composition Shingles, Part 4

Adhesive Strips

Cellophane Strips

Mastering Roof Inspections: Asphalt Composition Shingles, Part 5

TYPES of ASPHALT SHINGLES

Mastering Roof Inspections: Asphalt Composition Shingles, Part 6

PERFORMANCE STANDARDS

Mastering Roof Inspections: Asphalt Composition Shingles, Part 7

Variations Among Asphalt Composition Shingles

Mastering Roof Inspections: Asphalt Composition Shingles, Part 8

ASPHALT SHINGLE WARRANTIES

Mastering Roof Inspections: Asphalt Composition Shingles, Part 9

FIELD-CHECKING SHINGLE THICKNESS

Mastering Roof Inspections: Asphalt Composition Shingles, Part 10

PROBLEMS WITH ASPHALT SHINGLES

Mastering Roof Inspections: Asphalt Composition Shingles, Part 11

LONG-TERM SERVICE LIFE

Proper Installation

Shingle Quality

Multiple Layers

Directional Orientation

Roof Design

Mastering Roof Inspections: Asphalt Composition Shingles, Part 12

Climate Zone

Thermal Cycling

Shingle Color

Home Site Conditions

Elevation

Quality of Maintenance

Mastering Roof Inspections: Asphalt Composition Shingles, Part 13

SOURCES Of DAMAGE

Installation

Building Codes

Mastering Roof Inspections: Asphalt Composition Shingles, Part 14

UNDERLAYMENT

The IRC and Manufacturers' Recommendations

Pitch Requirements

Underlayment Installation Requirements

Steep-Slope Roofs

Low-Slope Roofs

Fasteners

Mastering Roof Inspections: Asphalt Composition Shingles, Part 15

UNDERLAYMENT in VALLEYS

Mastering Roof Inspections: Asphalt Composition Shingles, Part 16

FLASHING

IRC Requirements

ROOF-WALL INTERSECTIONS

Headwall Flashing

Mastering Roof Inspections: Asphalt Composition Shingles, Part 17

SIDEWALL FLASHING

Step-Flashing

Counter-Flashing

Sidewall Defects

Wall-Covering Clearance

Mastering Roof Inspections: Asphalt Composition Shingles, Part 18

COUNTER-FLASHING

Counter-Flashing at Brick Walls

Counter-Flashing at Stone Walls

Mastering Roof Inspections: Asphalt Composition Shingles, Part 19

Kickout Flashing

Changes in Roof Slope or Direction

Valleys

Hips

Mastering Roof Inspections: Asphalt Composition Shingles, Part 20

Changes in Pitch

Drip-Edge Flashing

Roof Penetrations

Skylights

Mastering Roof Inspections: Asphalt Composition Shingles, Part 21

Mechanical Attachment Points

Mastering Roof Inspections: Asphalt Composition Shingles, Part 22

SHINGLE INSTALLATION METHODS

Slope Limitations

Valley Types

Open Valleys

Closed Valleys

Cut Valleys

Woven Valleys

Mastering Roof Inspections: Asphalt Composition Shingles, Part 23

SHINGLE INSTALLATION METHODS

RACKING

Mastering Roof Inspections: Asphalt Composition Shingles, Part 24

FASTENERS

Disclaim Proper Fastening

Jurisdictional Requirements

Fastener Type

Nails

Mastering Roof Inspections: Asphalt Composition Shingles, Part 25

Depth of Penetration

Fastener Placement

Conventional Patterns

High-Wind Patterns

Mastering Roof Inspections: Asphalt Composition Shingles, Part 26

Substrate Holding Power

Hand-Sealing Shingles

Checking for Proper Fastening

Checking Shingle Bond

Mastering Roof Inspections: Asphalt Composition Shingles, Part 27

RE-ROOFING OVER EXISTING SHINGLES

Reduced Impact Resistance

Bridging and Nesting

Mastering Roof Inspections: Asphalt Composition Shingles, Part 28

INCREASING ROOF WEIGHT

Mastering Roof Inspections: Asphalt Composition Shingles, Part 29

ASPHALT SHINGLE WEATHERING

Shingle Quality

Structure Orientation

Degree of Roof Slope

Climate

Thermal Cycling

Roof Color

Elevation

Roof Structure Ventilation

Quality of Maintenance

ASPHALT SHINGLE LIFESPAN

Packaging

Installation

Slow, Prolonged Aging

Accelerating Deterioration

Mastering Roof Inspections: Asphalt Composition Shingles, Part 30

Moisture

Effects of Moisture

Ice Dams

Mastering Roof Inspections: Asphalt Composition Shingles, Part 31

The Asphalt Layer

Volatiles

Mastering Roof Inspections: Asphalt Composition Shingles, Part 32

DUCTILITY

Filler

Polymers

Transition Temperature

Mastering Roof Inspections: Asphalt Composition Shingles, Part 33

GRANULE LOSS

New Roofs

Uniform Granule Loss

Slope Orientation

Batch Problems

Flaking

Foot Traffic

Mastering Roof Inspections: Asphalt Composition Shingles, Part 34

ASPHALT SHINGLE MANUFACTURING DEFECTS

Inadequate Asphalt Coating

Blister Pops

Spliced Shingles

Mastering Roof Inspections: Asphalt Composition Shingles, Part 35

COSMETIC ISSUES

Visual Issues

Shingle Colors

Mixing Shingle Lots

Oil and Dust

MANUFACTURING VARIATIONS

Granule Tilt

Machine-Speed Granule Tilt

Granule Sizing

Machine-Speed Granule Blend

Granule Embedment

Mixing Algae and Non-Algae-Resistant Shingles

Mastering Roof Inspections: Asphalt Composition Shingles, Part 36

MECHANICAL DAMAGE

Tool Damage

Impact

Scuffing

Marring

Intentional Damage

Mastering Roof Inspections: Asphalt Composition Shingles, Part 37

SUBSTRATES

Wood Board

Plywood and OSB

Sheathing Thickness

Modern Standards

H-Clips

Mastering Roof Inspections: Asphalt Composition Shingles, Part 38

SHINGLE SPLITTING

Splitting vs. Cracking

THERMAL SPLITTING

Roof-Structure Assembly

Splitting Over Shingle Joints

Mastering Roof Inspections: Asphalt Composition Shingles, Part 39

SUBSTRATE MOVEMENT

Sheathing Expansion and Contraction

Initial Conditioning

Seasonal Fluctuation

Shingle Splitting

Shingle Buckling

Mastering Roof Inspections: Asphalt Composition Shingles, Part 40

BUILDING DESIGN

Roof-Structure Ventilation

Cooling Season

Heating Season

Moisture Problems

Mold Growth

Ice Dams

Mastering Roof Inspections: Asphalt Composition Shingles, Part 41

ENVIRONMENTAL DAMAGE

Tree Damage

Animal Damage

Biological Growth

Algae

Preventing Algae Growth

Mastering Roof Inspections: Asphalt Composition Shingles, Part 42

Biological Growth

Moss

Lichen

"Tobacco-Juicing"

Mastering Roof Inspections: Asphalt Composition Shingles, Part 43

HAIL DAMAGE

Impact Resistance

Characteristics of Damage

Mastering Roof Inspections: Asphalt Composition Shingles, Part 44

Mat

Asphalt Composition

Lack of Studies

UV Radiation

Conclusion

Mastering Roof Inspections: Asphalt Composition Shingles, Part 45

DAMAGE to the GRANULE LAYER

Functional Damage

Asphalt Quality

Hailstone Properties

"Hitchhikers"

Wind-Driven Hail

Mastering Roof Inspections: Asphalt Composition Shingles, Part 46

Area of Impact

Angle of Impact

Temperature

Substrate Support

Hail Damage vs. Blisters

Mastering Roof Inspections: Asphalt Composition Shingles, Part 47

Material Properties

Intentional Damage

Mastering Roof Inspections: Asphalt Composition Shingles, Part 48

Ball-Peen Hammers

Characteristics of Damage by Ball-Peen Hammers

Claw Hammers

Coins

Golf Balls

NON-INTENTIONAL, NON-HAIL DAMAGE

Tool and Equipment Damage

Mastering Roof Inspections: Asphalt Composition Shingles, Part 49

WIND DAMAGE

Wind-Resistance Standards

Wind Factors

Failure Modes

Tab Uplift

Shingle Pull-Over

Creasing and Tearing

Mastering Roof Inspections: Asphalt Composition Shingles, Part 50

Blow-Off

Adhesive Strips

Transfer

Inflation

Mastering Roof Inspections: Asphalt Composition Shingles, Part 51

Hand-Sealing Shingles

Rake Edges

Aging

Checking for Proper Fastening

Hand-Sealing Shingles

Mastering Roof Inspections: Asphalt Composition Shingles, Part 52

TYPES of SHINGLE DAMAGE

Creased or Broken Tabs

Debris

Shingle Blow-Off

Mastering Roof Inspections: Asphalt Composition Shingles, Part 53

FASTENERS

Jurisdictional Requirements

Fastener Types

Staples

Nails

Proper Fastener Installation

Fastener Placement

The Holding Power of the Substrate

Inadequate Penetration

Mastering Roof Inspections: Asphalt Composition Shingles, Part 54

INDIVIDUAL SHINGLE REPLACEMENT

Performing the Inspection

On the Roof

Checking Shingle Bonding

Shingle Fastening

Shingle Problems

Flashing Problems

Underlayment Problems

Mastering Roof Inspections: Asphalt Composition Shingles, Part 55

Attic Area Roof Inspection

Penetrations

Poor Connections

Mastering Roof Inspections: Attic Area Roof Inspection

Attic Ventilation Systems

Roof Structure Ventilation

Cools the Roof

Cools the Living Space

Removes Moisture

ACTIVE VENTILATION SYSTEMS

Thermostatically Controlled Fan

Whole-House Fan

Backdrafting

Mastering Roof Inspections: Attic Ventilation Systems, Part 1

PASSIVE SYSTEMS

Soffit Vents

Gable Vents

Roof Vents

Wind Turbine

Mastering Roof Inspections: Attic Ventilation Systems, Part 2

Continuous Ridge Vent

Adequate Ventilation

RADIANT BARRIERS

Mastering Roof Inspections: Attic Ventilation Systems, Part 3

Flashing

IRC Requirements

Corrosion

Mastering Roof Inspections: Flashing, Part 1

HEADWALL FLASHING

SIDEWALL FLASHING

Step Flashing

Tile Requires Pan Flashing

Step Flashing Sizes

Mastering Roof Inspections: Flashing, Part 2

COUNTER-FLASHING

Counter-Flashing at Brick Headwalls and Sidewalls

Mastering Roof Inspections: Flashing, Part 3

KICKOUT FLASHING

Mastering Roof Inspections: Flashing, Part 4

VALLEYS

Open Valleys

Closed Valleys

Mastering Roof Inspections: Flashing, Part 5

CHANGES in PITCH

DRIP EDGE

Mastering Roof Inspections: Flashing, Part 6

Hail Damage

Hail Damage: Where and When?

Mastering Roof Inspections: Hail Damage, Part 1

DEFINING HAIL DAMAGE

Functional Damage

Cosmetic Issues

Mastering Roof Inspections: Hail Damage, Part 2

HAIL DAMAGE CHARACTERISTICS

IMPACT ENERGY

Size

Mastering Roof Inspections: Hail Damage, Part 3

Density

Velocity

Variation Within Storms

Mastering Roof Inspections: Hail Damage, Part 4

Shape

Angle of Impact

Directionality

Mastering Roof Inspections: Hail Damage, Part 5

Type of Roof-Covering Material

Roofing Material Condition

Part of the Roofing Material Hit

Nature of the Substrate

Temperature of the Roofing Material

Mastering Roof Inspections: Hail Damage, Part 6

FORENSICS of HAIL DAMAGE

COLLATERAL DAMAGE

Spatter

SOURCE of DAMAGE

Mastering Roof Inspections: Hail Damage, Part 7

Directionality

Random Fall Pattern

Intentional Damage

Age of Damage

Mastering Roof Inspections: Hail Damage, Part 8

IDENTIFYING COLLATERAL DAMAGE

Elevation Damage

Gutters and Downspouts

Mastering Roof Inspections: Hail Damage, Part 9

Elevation Damage

Windows and Doors

SIDING

Vinyl Siding

Mastering Roof Inspections: Hail Damage, Part 10

Fencing

Painted Surfaces

Air-Conditioning Units

Electrical Panels

Window Well Covers

Directional Clues

Mastering Roof Inspections: Hail Damage, Part 11

HAIL DAMAGE on the ROOF

Test Squares

Number of Hits

Slope/Roof Replacement

Disagreements

Resolving Disagreements

Mastering Roof Inspections: Hail Damage, Part 12

Metal Roofs

Structural and Architectural Metal Roofing

Energy State of Metals

Mastering Roof Inspections: Metal Roofs, Part 1

CORROSION

Galvanic Crevice Corrosion

Corrosion

Filiform Corrosion

Mastering Roof Inspections: Metal Roofs, Part 2

METALS USED FOR ROOFING

Naturally Weathering

Copper

Aluminum

Mastering Roof Inspections: Metal Roofs, Part 3

Steel

Coated Steel

Galvanized Coating

Galvalume®

Mastering Roof Inspections: Metal Roofs, Part 4

BARRIER COATINGS

Types of Paint

Mastering Roof Inspections: Metal Roofs, Part 5

DAMAGING CONDITIONS

Surface Defects

Mastering Roof Inspections: Metal Roofs, Part 6

METAL ROOF INSTALLATION

Mastering Roof Inspections: Metal Roofs, Part 7

FASTENING METHODS FOR METAL PANEL ROOFS

Mastering Roof Inspections: Metal Roofs, Part 8

METAL SHINGLES

Mastering Roof Inspections: Metal Roofs, Part 9

HAIL DAMAGE to METAL ROOFS

WIND DAMAGE to METAL ROOFS

Mastering Roof Inspections: Metal Roofs, Part 10

Mastering Roof Inspections: Moisture Problems

Mastering Roof Inspections: Personal Protective Equipment

Mastering Roof Inspections: Pests

Mastering Roof Inspections: Photography

Mastering Roof Inspections: Respiratory Protection

Roof Drainage Systems

GUTTERS

Mastering Roof Inspections: Roof Drainage Systems, Part 1

DOWNSPOUTS

Interior Downspouts

Mastering Roof Inspections: Roof Drainage Systems, Part 2

Roof Framing

CONVENTIONAL ROOFS

Mastering Roof Inspections: Roof Framing, Part 1

METAL CONNECTIONS and FASTENERS

Fastener Failure

Mastering Roof Inspections: Roof Framing, Part 2

ROOF TRUSSES

Mastering Roof Inspections: Roof Framing, Part 3

Roof Penetrations

CHIMNEY INSPECTION

FLASHING

Mastering Roof Inspections: Roof Penetrations, Part 1

Cricket

Cap

Flue

Spark Arresters

Attic Chimney

Mastering Roof Inspections: Roof Penetrations, Part 2

VENTS

Mastering Roof Inspections: Roof Penetrations, Part 3

Mastering Roof Inspections: Roof Penetrations, Part 4

SKYLIGHTS

MECHANICAL ATTACHMENT POINTS

Mastering Roof Inspections: Roof Penetrations, Part 5

Roof Styles

Mastering Roof Inspections: Roof Styles

Slate Roofs

Mastering Roof Inspections: Slate Roofs, Part 1

PROPERTIES OF SLATE

Slate Lifespan

Foreign Slate

Mastering Roof Inspections: Slate Roofs, Part 2

SLATE ROOF STYLES

Mastering Roof Inspections: Slate Roofs, Part 3

SLATE DURABILITY

Mastering Roof Inspections: Slate Roofs, Part 4

SLATE FABRICATION and INSTALLATION

Mastering Roof Inspections: Slate Roofs, Part 5

Mastering Roof Inspections: Slate Roofs, Part 6

Mastering Roof Inspections: Slate Roofs, Part 7

Mastering Roof Inspections: Slate Roofs, Part 8

SLATE INSPECTION

Accessing Slate Roofs

Contractor Qualifications

Broken Slate

Snow Guards

Gutters

Cleaning Slate

Slate Roof Design

Mastering Roof Inspections: Slate Roofs, Part 9

Damaged Underlayment

Leaking Slate Roofs

Insects

"Chattering"

Mastering Roof Inspections: Slate Roofs, Part 10

REPAIRING FIELD SLATES

Mastering Roof Inspections: Slate Roofs, Part 11

HAIL DAMAGE to SLATE ROOFS

Mastering Roof Inspections: Slate Roofs, Part 12

COMPOSITE SLATE

Warranties

Mastering Roof Inspections: Slate Roofs, Part 13

Tile Roofs

Side Profiles

Interlocking Tiles

Overlapping Tiles

Butting Tiles

Birdstop

Mastering Roof Inspections: Tile Roofs, Part 1

TILE INSTALLATION

Minimum Roof Slope

Roof Sheathing

Underlayment

Flashing

Fasteners

Mastering Roof Inspections: Tile Roofs, Part 2

CONCRETE TILES

Mastering Roof Inspections: Tile Roofs, Part 3

CONCRETE TILE INSPECTION

Mastering Roof Inspections: Tile Roofs, Part 4

CLAY TILE MANUFACTURING

Mastering Roof Inspections: Tile Roofs, Part 5

CLAY TILE INSTALLATION

Mastering Roof Inspections: Tile Roofs, Part 6

Underlayment

The PURPOSES of UNDERLAYMENT

Mastering Roof Inspections: Underlayment, Part 1

TYPES of UNDERLAYMENT

ASPHALT-SATURATED FELT

Mastering Roof Inspections: Underlayment, Part 2

RUBBERIZED ASPHALT

Mastering Roof Inspections: Underlayment, Part 3

Non-Bitumen Synthetic Underlayment

Mastering Roof Inspections: Underlayment, Part 4

FACTORS AFFECTING UNDERLAYMENT

Climate Types

Roof Design

Mastering Roof Inspections: Underlayment, Part 5

Wind Damage

Mastering Roof Inspections: Wind Damage, Part 1

FACTORS AFFECTING WIND SPEED

Height Above the Ground

Wind Speed

Mastering Roof Inspections: Wind Damage, Part 2

HOW WIND CREATES DAMAGE

Mastering Roof Inspections: Wind Damage, Part 3

WIND DAMAGE CHARACTERISTICS

Mastering Roof Inspections: Wind Damage, Part 4

MITIGATING FACTORS

Mastering Roof Inspections: Wind Damage, Part 5

PERFORMING a WIND-DAMAGE INSPECTION

ELEVATION DAMAGE

Mastering Roof Inspections: Wind Damage, Part 6

Wood Shakes and Shingles

Manufacturing and Application Standards

Preservative-Treated

Mastering Roof Inspections: Wood Shakes and Shingles, Part 1

Grading Authority

Mastering Roof Inspections: Wood Shakes and Shingles, Part 2

UNDERLAYMENT AND INTERLAYMENT

Mastering Roof Inspections: Wood Shakes and Shingles, Part 3

FASTENERS

WOOD ROOF PROBLEMS

Weathering

Extractive Bleeding

Mastering Roof Inspections: Wood Shakes and Shingles, Part 4

Rates of Weathering

Distortion

Checks

Splitting

Mastering Roof Inspections: Wood Shakes and Shingles, Part 5

MECHANICAL DAMAGE

ENVIRONMENTAL PROBLEMS

Mastering Roof Inspections: Wood Shakes and Shingles, Part 6

WOOD ROOF MAINTENANCE

Mastering Roof Inspections: Wood Shakes and Shingles, Part 7

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