Roof inspection manual

NC Storm Repair, LLC [ROOF INSPECTION MANUAL]

Roof Inspection Manual Page 1

Roof Inspections: Roof Styles

Gable

Gable roofs are one of the most common styles. They’re easily identified. They have two slopes and the ridge extends the length of the home. The lower, level edges of the roof are called the “eaves,” and the sloped edges are called the “gables” or "rakes.” (We use both terms.)

Hip

There are two types of hip roofs, and both have four slopes. The basic hip roof has a level ridge, but the ridge doesn’t extend all the way to the exterior walls. Instead, hip rafters slope diagonally down to each corner.

The photo above shows a “full hip” roof. Full hip roofs have no real ridge. The hip rafters all meet to form a point at the peak of the roof.

Mansard

Mansard roofs were invented by the French when owners were taxed by the height of the building as measured to the roof eave. They’re short, steep roofs installed around the perimeter of what’s usually (but not always) a flat-roofed building.

Some of these roofs are nearly vertical, and this can cause installation problems which will vary with the different types of roof-covering materials.



Flat

“Pitch“ is the term used to describe the degree of roof slope.Flat roofs have one slope but very little pitch. A typical pitch would be ¼-inch per foot.

Flat roofs may drain over the roof edges or through scuppers installed in a parapet wall built around the perimeter.

Flat roofs are low-slope roofs. Since this series focuses on steep-slope roofs, we won’t be talking much about flat roofs. Low-slope and steep-slope roofs have different requirements.

Shed

Shed roofs have one slope but more pitch than a flat roof. Because shed roofs are often used for additions, one potential problem area is along the upper edge of the shed roof where it ties into the wall of the original home.

Gambrel

Gambrel roofs are usually associated with barns but are not uncommon on homes. They have two slopes, each of which changes pitch in a convex manner. The point at which the roof changes pitch should have metal flashing.

This barn is located in an area so windy that whenever the wind stops blowing, all the chickens fall over.

Bonnet

Bonnet roofs have a change of pitch but are concave -- the opposite of a gambrel.



Butterfly Roof

This is a style seen less often, but you will see them occasionally. When you inspect a home with a butterfly roof, look closely at the ceiling and floor beneath the low point.

The house in this photograph had recently sold and the sellers had hired a contractor to install a new roof. The buyers moved in… it rained… and the roof leaked. The buyers had to hire both a (different) roofing contractor and a floor contractor.

The roof wasn’t likely to leak due to the design alone, so this well-known architect designed not one, but two penetrations into the low point. The only things lacking are an anchor and a bilge pump!

ROOF FEATURES

Clerestory

These photos show roofs with clerestory windows. Although the term “clerestory” refers to the position of the windows, it also generally describes their position as incorporated into a shed roof. In other words, “clerestory” is commonly used to refer to the combination of roof and windows.

Clerestory windows should have adequate clearance between the sills and the roof below in areas with heavy snowfall. This home doesn’t and is more likely to leak. They should also have proper sidewall flashing.



Cupola

Cupolas are small structures built into the peak of a roof, often to provide light to the area below. The inspection concern is the roof framing supporting the cupola. Although the framing will typically be hidden behind interior wall-covering materials, look for signs of movement, such as cracking. Other vulnerable areas are headwall and sidewall flashing.

Conical Roofs

Conical roofs are often used to cover towers, as you see here, and are often steep. This first photograph shows a conical roof that is actually a series of tapered flat roofs, creating a series of hips.

Installing round conical roofs requires special roofing techniques to get shingles to lie flat, especially near the peak.

In this photograph, you can see that four tiny dormers have been installed near the peak.

Inspecting these steep roofs closely is difficult (or impossible) without special equipment, so you should get as close as you can using binoculars to look for signs of leakage beneath these roofs.

Inspection concerns include flashing at the round sidewalls and areas at which conical roofs intersect with roofs of other shapes. Specially-shaped crickets or flashing may be needed to provide long-term protection against leakage. Crickets are shown here outlined in red.

These areas of intersection (which are difficult to see because they’re on the backside of the roof) often collect debris, such as leaves and sediment. This debris holds moisture against the roof and flashing, which often corrodes more quickly than on the rest of the roof. So, the areas of intersection are difficult to see, and they’re weak point,.



If you can’t confirm the condition of the roofing on the backside of a conical roof, you need to disclaim it and recommend inspection by a qualified roofing contractor. A contractor may need to hook a ladder over the ridge in order to get high enough on the roof to see the backside of a conical roof clearly. This is especially true when the roof is covered with fragile materials, such as slate or tile.

Dormers

Dormers are projections built into the slope of a roof. Here, you see dormers with gable, hip and shed roofs. Inspection concerns are valleys, headwall and sidewall flashing.

Other Roof Combinations and Styles

You’ll often see several roof styles combined on one home... and sometimes……you’ll see roof styles for which there really is no name.

The structure above is a dormer because it’s a projection built into the slope of a roof. The structure below is a second story, since the exterior wall is continuous from foundation to roof.

The only limitations to the number of styles possible are the human imagination, the laws of physics, and the depth of the homeowner’s pockets.

Each different style of roof and roof feature has its weak points. Once you learn what these are, you’ll know where to expect problems. With all roofs, weak points are:

• places where roof-covering materials change; • places where the roof changes direction; • places where materials are used that have a relatively short lifespan; • roof penetrations; and • portions of the roof that lie in the drainage path.



Roof Inspections: Hail Damage, Part 1

Hail is big business. The cost of repairing hail damage in the United States averages about $1 billion a year.

On April 14, 2006, a single hailstorm in Indianapolis, Indiana caused $1.3 billion in damage. According to the Insurance Information Institute, for every $100 of homeowner premiums collected by the insurance industry, $30 goes to paying for wind and hail damage. That’s compared to $16 for fire damage, and $11 for water damage. Hailstorms can also be lethal. In 2002, a hailstorm in China’s Hunan province killed 25 people and injured hundreds more.

Courtesy of NCAR

A hailstorm in Aurora, Nebraska dropped the biggest hailstone on record in North America.

Hail damage is identified by inspecting the roof and home exterior. Those performing inspections are most likely to be members of the insurance, roofing or home inspection industries.



Even though hail damage in the U.S. is widespread and costly, there is a lack of uniform criteria for identifying wind and hail damage among these industries. Although severe hail damage is easy to identify, roofs may be damaged to a lesser degree, and inspectors from different industries sometimes disagree about what is and what isn’t hail damage.

The goal of this portion of "Mastering Roof Inspections" is to provide detailed, accurate criteria for the identification of hail damage.

If inspectors from these industries use the same criteria for identifying damage, then there’s a good chance of reducing disagreement among the industries, as well as confusion for homeowners who are looking to these professionals for guidance.

Hail damage can be identified based on different types of roof-covering materials, so we’ll cover the characteristics of hail damage that are common to the major steep-slope, residential roof-covering materials, particularly, those materials specified in the N.C. Storm Repair, LLC. courses on asphalt shingles, wood, tile, metal and slate roofs.

First, lets talk about how hail forms.

The uneven heating of the earth’s surface creates wind as warm air rises, pulling replacement air in behind it. Rising air is called an “updraft,” and the process is called “convection.”



This tornado began as an updraft. Eventually, the updraft began to rotate, and the tornado was born.

Although updrafts are associated with a number of different types of storms, we’re concerned with one particular type called a “supercell.” In addition to tornadoes, supercells can produce

hail.

Hail is composed of balls of ice called “hailstones.”

Hailstones are formed inside storms when updrafts carry dirt and dust particles high into the cold, upper parts of storm clouds. Super-cooled water clings to the particles and then freezes, forming tiny ice balls. Once the updraft weakens, the ice balls fall until they’re lifted back into the clouds again by another



updraft. As this process is repeated, the ice balls accumulate layers of ice and get bigger. Once they become too heavy to be supported by the wind, they fall from the sky as hailstones.

Hail Damage: Where and When?

Although hail can fall anywhere on earth where conditions are right, the majority of hail damage in the U.S. occurs in the midwest, from south Texas northward to Minnesota, and from Colorado eastward to Illinois.

Another band of high hail damage potential runs east to Virginia.

The hail season generally starts in the southern U.S. in late March and continues through August. Storms

typically moved from the Southwest toward the Northeast.



Roof Inspections: Hail Damage, Part 2 DEFINING HAIL DAMAGE Although it may be relatively short, this is one of the most important articles in this series. For insurance purposes, hail damage to roofing-covering materials is defined as either "functional" damage or "cosmetic" damage. Being able to determine the difference between the two is crucial, and has long been a point of contention between members of the insurance industry and members of the roofing industry, primarily because of ignorance of or disagreement over basic criteria.

Functional Damage Functional damage is damage which:

• diminishes the ability of a roof to shed water; and/or • reduces the roof's expected long-term service life.

Functional damage varies with different types of roof-covering materials. Wood roofs will show functional damage differently than asphalt and tile roofs.

Cosmetic Issues Damage which doesn’t meet the definition of “functional” is considered “cosmetic.” Cosmetic issues may be discoloration or damage which doesn’t affect the lifespan of the roofing material or reduce its ability to shed water. Cosmetic damage is that which only affects the appearance of a material, or affects its functionality to only a minor degree. Some examples are…

…minor localized granule loss from hailstrikes to asphalt shingles, or…



…hail dents in metal vents, gutters and downspouts.

Cosmetic issues also vary with the type of roof-covering material installed. Insurance companies may or may not pay for cosmetic damage. An example of when an insurance company might pay for cosmetic damage is when the damage results in a financial loss to the policyholder, or if reimbursement is required by state or local law. Whether cosmetic damage may be compensated for also varies somewhat by the policies of various insurance companies, and how each policy is written. A “loss” is usually interpreted to mean a loss in the home’s value. An example of this might be an expensive copper roof which is badly dented by hail. A loss may vary by location. If the copper roof is in a highly visible portion of a high-end home, damage may more likely be paid for than if it were on a portion of a second-story roof which is barely visible from the ground. Even when a damage claim is paid, payment may be half of the replacement cost, or even less. Copper roofs last so long that hail impact-dents are an expected part of their history and character.




HAIL DAMAGE CHARACTERISTICS Let’s take a look at the different factors which determine how severe hail damage can be. Hail damage has certain characteristics which vary with both the different properties of hail, and with the properties of the various roofing materials that hail hits. First, let’s examine the different properties of hail. The severity and appearance of the damage caused by hailstones depends on a number of variables. The size, density, free-fall velocity, the shape of the hail, its directionality, and angle of impact can all affect the damage you see during an inspection.

IMPACT ENERGY Three of these properties -- size, density, and free-fall velocity -- affect what’s referred to as the “impact energy” of hail. Impact energy is the amount of energy transferred to the roof-covering material when the hailstone strikes. Impact energy is the most important factor influencing the severity of damage caused by a hailstone. A hailstone carrying a lot of impact energy will do more damage than one carrying less impact energy.

Size Size is an important factor because larger hailstones are heavier and fall faster than smaller hailstones, and so they carry more impact energy.

Natrional Center for Atmospheric Research

The largest hailstone ever recorded in North America fell in Aurora, Nebraska in 2006. Hail size is described by comparing it to a common object. Here are some commonly used descriptions:

• pea = 1/4-inch in diameter; • marble = 1/2-inch in diameter; • dime or penny = 3/4-inch in diameter (hail the size of a penny or larger is considered

severe);



• nickel = 7/8-inch; • quarter = 1 inch; • golf Ball = 1½ inches; • tennis Ball = 2½ inches; • baseball = 2¾ inches; • tea cup = 3 inches; and • grapefruit = 4 inches.

TABLE 1

Material

Hail Size

Damage

Size

3-tab organic shingles 1-inch 25mm

3-tab fiberglass shingles 1¼-inch 32mm

cedar shingles 1¼-inch 1¼-inch

fiber-cement tiles 1¼-inch 1¼-inch

flat concrete tiles 1¼-inch 1¼-inch

heavy cedar shakes 1½-inch 38mm

30-year laminated shingles 1½-inch 1½-inch

built-up gravel roofing 2-inch 50mm

S-shaped concrete tiles 2-inch 2-inch

Table 1 shows the size of a hailstone typically required to damage various types of roof-covering materials. This is a general guide only, since the severity, appearance and likelihood of hail damage can be affected by a number of factors. You can see that organic 3-tab shingles are the most fragile, since they can sometimes be damaged by hail as small as 1 inch in diameter. Three-tab fiberglass, cedar shingles, fiber cement, and flat concrete tiles may begin to suffer damage when hail reaches about 1¼-inch in diameter. Heavy wood shakes and thicker fiberglass shingles may start showing damage when hail reaches about an 1½-inch. Concrete S-tiles can start showing damage when hail reaches about 2 inches. The size of a hailstone is determined by the number of ice layers it accumulates before it falls to the earth. Larger, more powerful storms with strong winds may keep hailstones aloft long enough for them to reach large sizes. It can be difficult to tell the size of a hailstone by the damage it leaves. Damage left by hailstones of the same size can vary, depending on the hailstones’ density, their angle of impact, and the properties of the material they hit. It’s also common for the size of hailstones to vary within a single storm. Hailstones at the leading and trailing edges of storms may be of a size different from those in the main body of the storm, so it’s not unusual to see damage to a property with characteristics of different sizes of hailstones. When discussing the importance of impact energy and the characteristics of hailstones, size is the easiest to estimate. You can’t tell the density or free-fall velocity of a hailstone by looking at the damage it leaves behind. But as you become more experienced at inspecting hail damage, you’ll become more skillful at judging the size of the hailstone by looking at the damage to a variety of materials.



Hard hailstones hitting soft, thin materials, such as aluminum vents, will leave a better indication of their diameter than soft hailstones hitting hard materials. You don’t really need to determine the actual size of the hailstone. Your mission is to identify functional damage, or the lack of damage. Size is just one more clue. Larger hailstones tend to be less spherical. They often grow not only by gaining ice layers, but also by colliding and merging with other hailstones.

National Center for Atmospheric Research

As hailstones collide, they can form odd, asymmetrical shapes, as you can see here. Each of these lobes was once an individual hailstone. Although recognizing damage from huge hailstones is easy, recognizing what is and isn’t damage from smaller, softer hail can be much more difficult.




Density

Studies have shown that hailstones vary in density. The density of a hailstone is an indication of how hard it is. The layers of ice, which accumulate as a hailstone grows, often contain air bubbles which make the hailstone softer, lighter and less likely to cause damage.

A low-density hailstone can have more in common with a snowcone than it does with a hailstone.

Softer hailstones leave distinctive marks called “spatter,” which can be a good indicator of the size, density and quantity of hail fall.



Although softer stones may not damage roof-covering materials, they may leave noticeable, temporary marks on whatever they hit. Instead of indentations, spatter often leaves marks resulting from the removal of surface oxidation, particulates such as dust and dirt, or microbial growth.

Velocity

Another word for the speed at which a hailstone falls out of the sky is its velocity. The velocity at which a

hailstone falls is limited by its aerodynamic shape, its size, and the quality of its surface.

The fastest speed at which an object of a specific shape can possibly fall is called its terminal velocity or

free-fall speed. The terminal velocity of hailstones is important because the faster a hailstone falls, the

more impact-energy it carries. A hailstone falling fast is more likely to cause damage when it hits than a

similar hailstone falling more slowly.

Hail Fall-Speed Table

(Greenfield, 1969)

Hail

Diameter Terminal

Velocity Impact

Energy

in. cm mi/hr m/sec ft.-lbs. Joules

1 2.5 50 22.3 <1 1.36

1¼ 3.2 56 25 4 5.42

1½ 3.8 61 27.4 8 10.85

1¾ 4.5 66 29.6 14 18.96

2 5.1 72 32 22 29.8

2¼ 5.8 76 34 34 46.01



Hail

Diameter Terminal

Velocity Impact

Energy

2½ 6.4 80 35.7 53 71.9

2¾ 7 84 37.6 81 109.8

3 7.6 88 39.6 120 162.7

This Hail Fall-Speed Table shows the terminal velocities for hailstones of different sizes, and the impact-

energy each size carries. It assumes that hail is smooth and spherical.

If you compare the speed and impact-energy of a 1-inch hailstone to that of a 3-inch hailstone of equal

density, it’s easy to see why larger hailstones do more damage. The 1-inch hailstone falls at about 50

miles per hour and carries less than 1 foot-pound of impact-energy. The 3-inch hailstone falls at almost

90 miles per hour and carries 120 foot-pounds of impact-energy.

Impact-energy increases exponentially as hailstone size increases.

Variation Within Storms

It’s not unusual for hail within a single storm to carry different amounts of impact-energy. Hail at the

leading and trailing edges of the storm may have characteristics different from hailstones falling from

the main body of the storm, since the conditions at the edges of the storm will be different from those

in the middle.




Shape

Hailstone shape is important because it affects the manner in which the impact energy from a falling hailstone is transferred to the material it strikes.

A conical hailstone hitting at the wide end will spread the energy of its impact over a larger area than a hailstone hitting at the narrow end. The smaller surface area of the narrow end will concentrate the force of the hailstone strike, which increases the chance of hail damage.

About 75% of hailstones are spherical, conical or ellipsoidal in shape -- ellipsoidal being like a slightly squashed sphere. Spherical is by far the most common shape, especially with small and medium-sized hail.

Occasionally, hailstones will form unusual geometrical shapes. Individual damage marks from stones like these will not fit the typical profile, although the overall pattern of damage across the roof and elsewhere around the home site will not be affected by hailstone shape.

Directionality

“Directionality” is a term used to describe the fact that hail usually blows in from a certain direction. Since hail is associated with storms, the roof slope and elevation facing the direction of the oncoming hailstorm will suffer the most severe damage. Although supercells in the West generally move from the Southwest toward the Northeast, this can vary.



The concentration of damage should vary according to which direction each home elevation faces. This photo shows a home that had 10 hits in the siding at the back of the home, but no hits at the front or sides.

The hail was not orange and did not do in the dog, although it may have clipped him. This area was hit by tennis ball-size hail. No wonder this poor dog is tired.

Hail can hit all exposed surfaces, so evidence of the direction from which hail came should be apparent on a number of different types of surfaces, and not just on the roof. Evidence of hail damage may be visible on a number of items around the home. This is called collateral damage. Examining collateral damage may give you useful information.

Occasionally, hail will fall almost straight down, and, in these situations, damage on different slopes may be similar, and collateral damage may be limited.



When you perform on-site inspections, you should see evidence of hail which is consistent in its directionality. If hail blew in from the Southwest, you would expect to see the most severe hail damage on surfaces facing that direction.

If you see hail damage of similar severity on both the north and south sides, that’s not consistent with damage from a single hailstorm, but is more likely to be damage from two separate hailstorms. You should compare the damage from each side, and look for signs that indicate damage of different ages. We’ll talk more about how to do that later.

Angle of Impact

Hail falling in storms with higher wind speeds will impact at a steeper angle than hail falling through calmer air.

The severity of damage from the angle of impact should be consistent with other evidence of directionality that you see on various surfaces around the property.

Blown hail will also produce more collateral damage than hail falling closer to straight down.




PROPERTIES of ROOFING MATERIALS

Let’s examine the properties that affect the impact-resistance of some of the common steep-slope roof-covering materials.

Resistance to hail damage depends upon a number of factors.

Type of Roof-Covering Material

The type of roof-covering material is one factor. Some types of materials and profiles are more resistant to damage than others. Metal roofs seldom suffer functional damage from hail. Many thousands of asphalt shingle roofs are damaged by hail every year.

Roofing Material Condition

The condition of the roofing material is another factor. These photos show a 20-year-old asphalt shingle roof which has suffered general granule loss.



You can see it accumulated in the gutters.



This condition was probably contributed to by widespread blistering, an example of which is shown above.

General granule loss is NOT considered to be functional damage.

The thickness of the roofing material will also affect the severity of damage. Assuming that we’re comparing similar materials, such as thick and thin asphalt shingles, thicker materials will typically resist damage better than thinner ones.

Nature of the Substrate

The characteristics of the substrate will also affect the severity of damage.

Thick, solid, smooth, single-layer substrates will improve the ability of the roof-covering material to absorb impact, and this reduces the chances of functional damage. Solid wood decks supply solid substrates. Layers of old roof-covering materials offer poor support against hail impact.

Part of the Roofing Material Hit

The amount of damage will also be affected by the part of the roofing material that’s hit.



The edges of roof components, such as wood and asphalt shingles, are more fragile and subject to damage than material in the middle of the components, since the edges have less surrounding material for support.

Ridge and hip cap shingles are poorly supported, so they are more likely to suffer hail damage.

Temperature of the Roofing Material



The temperature of the roofing material can also have an effect. Certain roof-covering materials, such as asphalt shingles, become increasingly brittle at lower temperatures. Brittle materials are less able to absorb impact without damage, so cold materials are more likely to be damaged by hail.

To review, the impact-resistance of a roof-covering material will be affected by the thickness of the

material, the nature of the roofing, and the condition of the roof-covering material.




FORENSICS of HAIL DAMAGE, Part 1

Next, we’re going to spend some time on the forensics involved in identifying hail damage. “Forensics” means looking at damage from a variety of perspectives, including close up – in fact, so close that you might need a magnifying glass to see tiny clues, such as scratches – and also from farther away, so that you can see the overall pattern of hail strikes. You’ll also look at places other than the roof.

COLLATERAL DAMAGE

Before you go up on the roof, it’s a good idea to walk the perimeter of the home to look at collateral damage. We’ll discuss collateral damage in more detail later in this series.

Spatter

Strikes from hailstones will usually leave one of two types of marks: spatter or indentations. Hailstones which leave spatter marks are more like "sloshballs" than hailstones. When these sloshballs strike, they remove oxidation, dust, dirt, and microbial growth from whatever they hit.



Here, you see spatter marks interspersed with an indentation that could be hail damage, along with damage -- a slice -- that was not caused by hail.



Over time, spatter marks will re-oxidize, become re-covered by particulates, and will blend in with the surrounding surface, so spatter is really temporary discoloration rather than damage.

The shape of a spatter mark can offer information about hail size and the direction of fall. The long axis of the spatter mark will align with the direction from which the hail came.

The width of the spatter mark will give a rough indication of the hailstone’s size for hail smaller than 2 inches. With hail larger than 2 inches, the width of the spatter mark will increase significantly in relation to the actual size of the hailstone which made it.

SOURCE of DAMAGE

Indentations can have many causes other than hail. So, in looking at damage to a downspout, for example, you’d want to take note of:

• the downspout material -- whether it's aluminum, galvanized steel or copper; • the number and concentration of indentations; and • whether the indentations have scratches or creases in them. Hail does not scratch or

crease metal.





These photos show actual hail damage to gutters. You can see that the force that created the indentations came from above.

Damage can come from a variety of sources. Here, you see damage that’s not consistent with hail damage. The force that created this damage did not come from above. The fact that the damage occurred in the same part of the gutter is another clue that it was not caused by hail. Chances are good that this damage occurred before the gutters were installed.





Directionality

We’ve talked about viewing evidence of a storm's direction by examining collateral damage. The same is true with the roof. You’ll usually see that damage is more serious on slopes facing the same direction. This is the direction from which the hail came. If opposite-facing slopes both have damage, you may be looking at damage from different storms. It’s possible that hail from one storm carried more impact-energy than hail from another. Look for differences in the age of damage.

It’s also possible that there was little wind and that hail fell nearly straight down.

Random Fall Pattern

The fall pattern should be random. Hail falls from thousands of feet in the air, so the pattern of damage across the roof should be random. If you see geometrical patterns of damage, examine the damage closely for evidence of causes other than hail.

Intentional Damage



Roofs are sometimes intentionally damaged by those wanting to defraud insurance companies to get a new roof. If you see damage that is concentrated in areas away from the roof edge,



or areas in which damage appears as a series of short arcs, or …

…damage which appears as separate groups, you should examine individual marks closely for signs of intentional damage. The details of intentional damage will vary with the type of roof-covering material.

Again, damage should be random across the roof. Hailstones may hit any part of the roof-covering material, including its edges, and you may see one indentation overlapping another. If you see damage which appears only in the same part of different shingles, look closely for evidence of other types of damage.

Age of Damage

The appearance of older damage usually is indicated by color. Hailstrikes often remove oxidation and particulates or expose new material, leaving the area of the strike a different color from the surrounding material.

Over time, the damaged materials will re-oxidize and become re-covered with particulates. So, although

some evidence of damage may remain visible, older damage may look different from newer damage.

The appearance of the difference will vary with the type of roof-covering material installed.





IDENTIFYING HAIL DAMAGE

Since hail is associated with storms, you may find wind and hail damage together as a result of a single storm.

Let’s go over some inspection methods you might use if you suspect that the home has hail damage.

IDENTIFYING COLLATERAL DAMAGE

Not all hail damage is found on the roof. Many materials at ground level can also be damaged by hail. Damage to items other than the roof is called “collateral damage.” The nature of collateral damage may give you information about hail size and density that will help you better understand damage you see on the roof.

Elevation Damage

The most important type of collateral damage is “elevation damage.”

Elevation damage is damage to those parts of the home on the exterior walls, such as siding and trim, windows, doors, window well covers, and any other building components that can be damaged by hail.

Collateral damage is more general, and might include lawn furniture, decorations, and freestanding components, such as air-conditioning units.

In performing the "elevation inspection," you’ll be examining everything you see when you step back from the exterior walls and look at the side of the home.

Depending on the material, you could be looking for cracks, dents, punctures, broken glass, spatter marks, and dislodged materials.

Remember that hail does not leave scratches in the material it hits, so if you see scratches in indentations, the damage was not caused by hail.

Hailstones do not produce damage with creases, so if an indentation is creased, it’s not hail damage.

All materials can be damaged by hail. Even concrete and steel can be damaged if the hail is big, hard, and wind-driven.



Let’s take a closer look at the components you’ll be examining when you inspect for elevation damage. We’ll start with the exterior wall components.

Gutters and Downspouts

Gutters and downspouts are often fabricated from steel, which is highly resistant to hail damage. Aluminum gutters can be damaged fairly easily. Copper is harder than aluminum, but softer than steel. In addition to the type of metal, damage to metal gutters and downspouts will depend on the thickness of the metal.

Vinyl gutters and leafguards will show punctures or cracks.

When you look at gutters, you’ll be watching for dents made by hail falling from above or blown from a particular direction. Hail striking the bottom of the gutter will create downward indentations.



Hail striking the front side of the gutter may create indentations either toward or away from the gutter channel, depending on the direction of hail fall. These are called "innies" and "outies."



Indentations to aluminum gutters and downspouts which are caused by hail are typically smaller than the diameter of the hail that hit them.

Damage from ladders leaning against a gutter and other mechanical damage should be fairly localized and easy to identify. A ladder will leave two scrapes or dents about 16 inches apart. Damage is usually in a spot where it would be convenient to place a ladder.

Not all damage you’ll see will be hail damage. This photo is an example of non-hail damage.

There are several clues:

• The force which created the upper indentation was from the side. Hail might be wind-driven, but hail with enough impact-energy to create a dent this severe would not be blown horizontally. This damage also includes creasing and chipped paint. Hail does not crease metal.

• The force which created the lower indentation was from below, which is inconsistent with hail damage.





Elevation Damage

Windows and Doors

Window screens can show streaking or damage from even relatively small or less dense hail.

Vinyl windows are vulnerable to hail damage, especially the sash and exterior bead.

Wood windows, doors and trim are sometimes clad with



aluminum on the exterior. This type of cladding, especially when it's used on horizontal surfaces, can show indentations and spatter marks from hail.

Fiberglass and vinyl windows may have cracked frames. Steel frame windows may have indentations and spatter marks, and, of course, all windows can have broken glass.

If hail carries enough impact-energy, it may break window panes.

Garage doors and trim are typically made of aluminum, and will show

damage.

While looking for hail damage, you’re not limited to using your eyes. You can also feel for it. If the surface you’re examining is in the shade, it may be easier to feel damage than see it. It’s often easier to see a hit if you use the side of a piece of sidewalk chalk to color the area around it, although this will create the illusion of larger damage than actually exists.



SIDING

Aluminum Siding

Aluminum siding is the type of siding most easily damaged by hail, with the damage appearing as indentations, as you can see in this photo. Soaking the siding with a hose will make the damage more apparent, so, if possible, spray it before you photograph it.

Also important to remember is that just because wetting the surface makes hail impressions easier to see doesn’t necessarily mean that the siding has suffered functional damage, such as fracturing, which allows moisture intrusion.

This damage was not caused entirely by hail. You can see spatter marks, but there is also more severe damage. Hail won’t leave damage which looks like a slice, and hail damage doesn’t appear as scratches.

Aluminum dryer vents will also show damage.

Spatter marks are areas where hail impact has removed oxidation from the surface. These marks

will re-oxidize and fade over time.

Hail fall is random. It’s not likely to leave marks of identical size, equal distances apart, or on the same part of different shingles, as you see here.



Vinyl Siding



Vinyl siding is easily cracked and broken. Large hail can leave spectacular damage. This neighborhood was hit by a storm that dropped hail in the size range of 1½-inch to 2½-inches.

Homes in surrounding neighborhoods had hardboard siding that showed only minor damage, such as chipped paint.



This storm left damage on downspouts, vinyl, wood and aluminum trim.



The entire neighborhood looked like it had been attacked by a battalion of teenagers with potato cannons.

Wood siding can be cracked, dented and broken. Lapped wood siding is more easily damaged than wood panel siding. Lapped siding on older homes was often manufactured from redwood, which is a relatively soft wood that becomes brittle with age.

Is this wood, or a composite with wood-grain overlay? Lack of splintering in the indentation suggests a

composite. You’ll sometimes need to look closely to make sure.



Paint may also be damaged if wood is indented. Again, look closely. This is a composite made to look like

wood shingles. The lack of space between each shingle is the telltale sign.





Identifying Elevation Damage

Fencing



Wood fencing may be dented or discolored by hail. This photo shows a fence which has been hit by small, hard hail.

Minor dents will often disappear with time as wood fibers, compressed by the hail's impact, swell as they absorb moisture from precipitation and humidity.

Discoloration from the removal of oxidation by the impact will typically blend in with the rest of the fence after a few months as the newly-exposed wood re-oxidizes.

Metal fences may also have oxidation removed, which will soon blend in with the rest of the fence.

Fences which have been painted may sustain damage to the paint, which will require re-painting the fence.

Vinyl fencing may be cracked or punctured, depending on its profile and the impact-energy of the hail which has hit it.

Painted Surfaces



Painted surfaces can be chipped and cracked by hail. Horizontal surfaces are more likely to show damage, and so are surfaces with older paint, low-quality paint, and surfaces that were not primed before they were painted.



Air-Conditioning Units

The heat-radiating fins of air-conditioning units are easily damaged by hail. The metal jacket of the unit may show damage from larger hail. Indentations on the thin aluminum fins can reflect fairly accurately the diameter of the hailstones which caused them.

If you see spatter marks on aluminum AC fins, they usually indicate that the hail was soft.

Hail indentations of the fins may be a covered loss, requiring fin combing or even replacement, so this should be included in the report.

Electrical Panels

A metal electrical panel is one more ground-level item which may show indentations, but, more typically, will show spatter marks from hail. Spatter marks on panels can help you determine the direction from which the hail came.



Window Well Covers

Window well covers may also take a beating and can sometimes give you a good idea of hail diameter, density, direction and quantity.

Directional Clues

If you see hail damage on different sides of the home, indicating that hail came from different

directions, you may be seeing damage from two different hailstorms. You should examine the evidence

closely for clues to differences in age of damage, similar color variations in similar materials due to

differing amounts of UV exposure, and oxidation.





Identifying Elevation Damage

HAIL DAMAGE on the ROOF

When inspecting for hail damage, it’s important to understand the methods used by insurance claims adjusters because if damage for which an insurance company will pay exists, it should be identified and documented using insurance company criteria.

Test Squares

Claims adjusters mark off test squares on a roof to document the extent of damage. The size and locations of test squares are the same no matter what roof-covering material is installed. Here are some test square details:

• Test squares are 10 feet by 10 feet. A square shape is used whenever possible, but if it’s not possible to use a square because of the roof shape, other shapes can be used. The test area size should always be 100 square feet, no matter what the shape.

• Test squares should be placed on each roof slope.

• They should be located in areas with the most damage. They should not be located in areas of a roof which are protected by things such as overhanging tree branches.



Number of Hits

Once the test square has been created, the adjuster counts the number of hailstrikes within the square. These hailstrikes have to meet the definition of functional damage. The number of hits required to replace that slope of roof will vary. Different insurance companies have different policies. Eight hits is a common number.

Slope/Roof Replacement

The decision of whether to replace individual slopes or to replace the entire roof requires weighing a number of factors. The age of the roof will be one factor. Older roofs are more likely to be replaced. Some insurance companies use a formula in making the decision.

Disagreements

Occasionally, a disagreement will arise among insurance companies, roofers, home inspectors and policy holders about whether damage meets the criteria for roof replacement.

One area with a lot of potential for disagreement is whether the damage meets the description of “functional damage.”

The characteristics of hail-caused functional damage vary with the different types of roof-covering materials. It is easier to identify functional damage on some materials than on others.

There’s more potential for disagreement with a material such as asphalt composition shingles, which may be damaged to some degree. It may be light damage, which does not meet the criteria for functional damage, or it may be serious damage, which does.

These issues are discussed in detail in N.C. Storm Repair, LLC.'s courses on the individual roof-covering materials.

Resolving Disagreements

The mechanisms for resolving disagreements can vary. The insurance policy is a contract, and in it are certain provisions for settling disputes. One involves an arbitration process where the policy holder and insurance company each appoint a representative, and those two agree on a third person. These three act as referees in the process. Reports from roofers and home inspectors are considered in reaching a determination. This process doesn’t get used very much. Instead, policy holders usually complain to the state's department of insurance, whose job is to make sure that the insurance company complies with the contract terms. They usually can’t force a company to pay for a roof if there is a lack of sufficient evidence showing roof damage, but they can encourage the company to pay if the damage criteria are met. They can sanction an insurance company if the company fails to follow the contract. Another option available to the policy holder who thinks that their insurance company has not acted according to their contract is to hire an attorney and file a lawsuit.



Roof Inspections: Wind Damage, Part 1

Courtesy of Mike Hollingshead

We know that hail is associated with storms. Usually, storms that drop hail also bring wind, as low-pressure fronts move in and out of the area. You may see damage from either one during an inspection.

WHAT CAUSES WIND?

In talking about wind damage, we should first cover some basics.

Wind is air moving from areas of high air pressure to areas of low air pressure. The greater the difference in air pressure between two points on Earth, the faster the air will move between them.



These differences in atmospheric pressure are created by uneven heating of the earth’s surface. Because of the earth’s shape and orientation to the sun, more warming takes place along the equator than at the poles. The different rates at which heat is absorbed and released by land, water and the atmosphere itself also contribute to thermal differences.

As air in warmer areas rises, cooler air moves in to replace it. It’s this replacement air that we experience as wind. The force that pulls the replacement air is called “convection.” Convection can cause both updrafts and downdrafts, which create wind with different characteristics, including varying:

• direction; • strength; • duration; and • speed.

Hurricanes



This process happens on both large and small scales. At the large end of the scale are hurricanes in which the area of strong winds might be between 25 and 150 miles wide. Hurricanes are classified according to wind speed:

• Category 1 = winds 74 to 95 miles per hour; • Category 2 = winds 96 to 110 miles per hour; • Category 3 = winds 111 to 130 miles per hour; • Category 4 = winds 131 to 155 miles per hour; and • Category 5 = winds greater than 155 miles per hour.

Tornadoes

Courtesy of Mike Hollingshead An example of much smaller but equally intense storms is tornadoes, which can have wind speeds of over 200 miles per hour, although wind speeds of less than 90 miles per hour are much more common. Tornadoes are also classified according to wind speed, as follows:

• F0 = winds 65 to 85 miles per hour (53.5% of all tornadoes); • F1 = winds 86 to 110 miles per hour (31.6% of all tornadoes); • F2 = winds 111 to 135 miles per hour (10.7% of all tornadoes); • F3 = winds 136 to 165 miles per hour (3.4% of all tornadoes); • F4 = winds 166 to 200 miles per hour (0.7% of all tornadoes); and • F5 = winds greater than 200 miles per hour (less than 0.1% of all tornadoes).



Many other convection-related wind events occur both with and without storms. Another condition that creates winds which can damage roofs is large-scale weather patterns that produce a strong, deep flow of air which passes over a mountain chain.

Forced up out of its natural path by the peaks, the wind seeks to return to its original level. But before settling back into a horizontal flow across the plains, it oscillates through several up-and-down cycles. As you can see in this illustration, these winds will actually bounce several times, and they can cause damage in certain areas with some predictability. If you’re inspecting in an area that fits this description, be looking for wind damage. These winds can slam into the ground at over 100 miles per hour.



You can sometimes spot these areas even when the wind is not blowing.

Over many thousands of years, the area near the base of the foothills where the wind first bounced has developed a trough, with soil scooped out by the wind.

This is often more pronounced below geological features which channel wind, such as canyons.




FACTORS AFFECTING WIND SPEED

Wind blows faster in open areas where there’s nothing to slow it down. The 2006 IRC (International Residential Code) lists four Wind Exposure Categories, labeled A, B, C and D, according to the degree of obstruction offered by the topography.

An example of Exposure A is an urban environment in which 50% or more of the buildings are taller than 70 feet.

The B Exposure is an urban or suburban environment with closely spaced homes or home-size buildings.

Exposure C is generally open terrain with scattered obstructions less than 30 feet tall.

Exposure D is flat, unobstructed areas, such as shorelines.

Height Above the Ground

Wind slows due to friction with obstructions. Because air is a fluid, obstructions near the ground can affect wind speed at a much greater height. Aerodynamic drag created by buildings taller than 30 feet can actually slow down air that is flowing at an altitude of 1,500 feet. This is because air moves by convection, so flowing air will have an effect on the air surrounding it.



If wind above 1,500 feet is blowing at 100 miles per hour, at Exposure C, it will have slowed to 62 miles per hour. At Exposure B, it will blow at 44 miles per hour, and the wind speed at Exposure A will be 27 miles per hour.

Since wind speeds are higher farther above the ground, taller buildings are exposed to higher wind speeds and will be more likely to suffer damage.

Wind Speed



Wind speeds reported by the National Weather Service are typically measured at a point 33 feet above the ground. This illustration shows how drastically wind speed can be reduced below 30 feet.

Wind speeds are usually reported as a sustained speed, which better reflects the average speed of the wind. Wind may also be reported as a three-second peak gust speed, which gives a better idea of the peak wind speeds that are sustained for only a short time.

Hurricane wind speed is measured as one-minute sustained winds, and may be measured at a much greater altitude by aircraft.

Wind Speed versus Wind Load

The wind load on a building is the force that the structure actually has to resist. Although wind speed will give some indication of the potential for damage, for a given speed, the wind load on a building can vary by more than 30%. Many factors influence the wind load, including:

• the building's shape; • its orientation to the wind; • the air density; and • the Wind Exposure Category where the building is located.

In Part 3, we’ll examine how the forces created by wind actually damage roofs.




HOW WIND CREATES DAMAGE UPLIFT

One of the destructive forces created by wind is uplift, which is the tendency of materials to be lifted into a wind-created vacuum. Uplift can be created by either of two physical conditions: loss of laminar flow, or increased wind speed. Both of these processes reduce the air pressure immediately above the roof-covering material.

Laminar Flow

Air flowing close to a surface is in a state called “laminar flow.” According to the laws of physics, flowing air will try to maintain contact with a surface. When that surface bends or curves sharply, the air flow can’t turn quickly enough to maintain contact, and it separates from the surface. We say that it “loses laminar flow.” This creates a vacuum, and anything that can move will be lifted up into that vacuum, if the vacuum is strong enough.



The other process that creates uplift is related to the fact that increasing wind speed lowers air pressure. Wind speed on the roof can be up to 2½ times the approach speed, which is the speed of the wind as it blows toward the home. Reduced air pressure from fast-moving air just above the surface of the roof also increases the amount of uplift.

Damage Location

Uplift can develop when wind blows across a roof.

The location of damage on a home will be affected by the orientation of the wind to the roof structure, and by the shape of the roof. In these illustrations, areas of uplift are shown in blue.



When wind blows perpendicular to the eaves and ridge, uplift is created along the upwind side of the lower roof slope and along the downwind side of the ridge.

When wind blows parallel to the eaves and ridge, uplift is created along the upwind rakes.



Wind blowing at the side of the building was deflected up and over the low-slope section, creating an area of strong uplift, which sucked shingles and underlayment right off the roof.

If uplift can lift a portion of the roofing material, more of the surface of that material will be exposed for the wind to push against, and it will be more easily displaced or blown off the roof.

Uplift is strongest at areas of the home where the wind loses laminar flow. The areas most commonly affected include:

• upwind eave edges; • upwind rakes; • upwind corners; and • the downwind side of ridges.

It’s at these areas that you’ll be looking most closely for wind-related damage.

In addition to uplift, areas which lose laminar flow also experience turbulence. This buffeting or fluttering effect can also loosen and displace roofing materials.

Positive Pressure

Positive air pressure is really just the wind pushing against something that offers resistance, such as a shingle tab that’s been raised by uplift, and flashing that protrudes enough for wind to push against it. Eaves and rakes are areas where roofing materials terminate, so they are especially vulnerable to damage from wind pressure.

Inflation



Wind inflation is similar to what happens when you blow up a balloon. It’s a result of positive air pressure. An extreme example of inflation is when wind blowing at the gable side of a home enters the space between the underlayment and roof-covering material. By inflating this space, wind can create damage by breaking the bonds of asphalt shingles.

In this photo, you can see the results of all three factors. The left side of the structure was the downwind side, and you can see that roofing materials were lifted into the vacuum created by loss of laminar flow.

The far-left corner had roof sheathing removed by a combination of uplift due to loss of laminar flow and inflation.

The near-right corner had roof sheathing removed by a combination of positive pressure and inflation.




WIND DAMAGE CHARACTERISTICS

• Direct and Indirect Damage • Determining Wind Direction • Material Condition • Building Characteristics • Mitigating Factors

Wind damage can be broken down into two basic types: direct and indirect. Direct damage occurs in conditions where roofing materials have been blown off, or have been damaged or displaced. Indirect damage is sustained from objects blown by the wind, which are referred to as "missiles."

Missiles

Roof-covering materials -- especially more brittle materials, such as tile -- may be damaged by wind-blown debris called missiles. Missiles can include other roofing on the home which has been pulled loose by the wind and blown onto roofing on adjacent roof slopes, or tree limbs, gravel, yard apparatus, or anything else capable of damaging roofing that has been carried aloft by the wind.

Missiles aren’t always items that were laying around the yard. Anything that has blown through the air and damages the roof or siding can be called a missile.



This particular missile was flying through the air under its own power before it was caught in a strong gust and blown into the side of the house.

Material Condition

Wind will damage materials in poor condition before it damages materials in good condition. In addition to deterioration of the roofing material itself, fastening systems deteriorate. In some systems, such as slate, the fasteners may be the weakest part of the system, corroding to a point at which wind will cause them to fail.

BUILDING CHARACTERISTICS

The nature of wind damage is also affected by the characteristics of the buildings themselves.

The important building characteristics which affect the potential for wind damage include the following.

Age of Home

Many new building materials and methods have been developed over the past 30 years. At the same time, our understanding of how buildings operate and react to conditions has improved, and, as a result, building codes have become more stringent.

Type of Construction



Wind damage varies with the type of construction. For example, mobile and modular homes are more likely to suffer damage than homes with a more substantial structure and higher-quality materials.

Building Quality

Some types of roofing materials are more vulnerable to wind damage than others. The type and quality of both the installation and the materials used in the roofing system will affect the chances for wind damage.

Roof Shape and Slope

Roof structures of different styles obviously have different shapes. Each shape will affect wind behavior differently, as well as the location and amount of damage.



Wind blowing parallel to the ridge of a gable roof will blow along the roof-covering materials, offering less chance for damage than wind blowing at a home that has a hip roof. The exception is the potential for damage along the rakes, and the potential for inflation, if wind gets beneath the roof-covering materials.

The hip roof will have a section of roof positioned perpendicular to the wind, offering more resistance and greater opportunity for damage to occur. The potential will vary somewhat with the type of roof-covering material and the quality of installation.




MITIGATING FACTORS

Mitigating factors are variables which influence the amount and nature of roof damage. Damage isn’t always limited to one factor. Variables can combine in different ways to create unique conditions.

Some variables, such as air density and the pattern of wind gusts, are aspects of wind damage that you won’t know about before you arrive at the inspection, and won’t be able to see once you’re there. But they can have a significant effect on the nature of the damage.

Let's examine the role these variables play in creating wind damage. The bottom line is whether or not the damage is consistent with damage actually caused by wind.

Some basic mitigating factors include the following.

Wind Speed

As previously mentioned, wind speed is related to the roof height above the ground, with speeds slowing closer to the ground. This image shows the wind blowing at 100 miles per hour at a height of 33 feet. At 5 feet above the ground, the wind speed is 66 miles per hour -- a loss of almost half the speed in only 25 feet.

The speed of the wind as it passes over the roof can be more than 2½ times the approach speed. The approach speed is the speed of the wind as it approaches the building.

Since higher wind speed can increase uplift, higher speeds increase the chances for damage.



Pattern of Gusts

As a storm moves into an area, wind may increase in speed at a relatively constant rate, or this growth may include strong gusts. During wind gusts, wind speed may increase dramatically in just a few seconds. This has a physical effect similar to an impact. Strong, sudden gusts may do more damage than winds of higher speeds which build and fade at a more gradual rate.

Air Density

Air density is affected by temperature. Cool air is denser than warm air. This means that if cool air and warm air are blowing at the same speed, cool, denser air will place a greater wind load on the building. A greater wind load has the potential to do more damage.

Wind Direction

Determining the direction from which damage-causing winds originated may help you recognize where to look for damage.

The orientation of damaged surfaces and displaced debris may provide clues.

• Look at the pattern of damage. Knowing how wind damage is created should help you determine the direction from which the wind was blowing.

• Look for distorted or displaced claddings, such as siding and trim. Damage should be more severe on the side of the home exposed to the most intense winds.

• Look for debris at the downwind side of the yard. • Many areas have predictable wind patterns. Strong coastal winds often blow in from the

ocean toward the shore. Homes located near features such as the mouths of canyons can have wind directed at them.



Roof Inspections:

Wind Damage, Part 6

PERFORMING a WIND-DAMAGE

INSPECTION

The same basic procedure is followed when inspecting for both wind and hail damage.

The inspection starts at the ground-level. As you inspect the home's exterior, you’ll be

looking for wind-caused collateral damage, including damage to the home's elevation, which is everything you see when you stand back and look at the side of the home.

Collateral damage also includes items in the yard, such as lawn furniture.

ELEVATION DAMAGE

In looking for wind damage, watch for the following:

• If you find roofing materials on the ground, there’s a good chance that it came from the roof of the home you’re inspecting.

By looking at the pieces, you may be able to spot deficiencies before you go onto the roof.

Looking at this piece, you can see where it pulled over the head of a nail. Obviously, this shingle was not well-bonded.

You can see that this shingle was fastened with staples which pulled through, so this roof was also not well-bonded.



Looking closely, you can see that the staples were not installed correctly. The crowns should have been parallel to the long side of the shingle.

• Look for damage to siding and trim.

Siding can suffer both direct and indirect damage.

• Pay attention to the roof edges, especially near the corners. Loose drip edges may be more visible from the ground than from the roof.

• Try to determine the direction from which the wind has blown by looking at conditions visible from ground-level. This will help in locating both wind and hail damage.

Once you’ve made your way around the home to document collateral damage, you’ll need to get onto the roof.



Roof Inspections: Accessing the Roof, Part 1

ROOF SAFETY

In deciding whether or not to walk a roof, the ability to accurately evaluate it is a skill that can be developed and improved with study and practice. There’s no formula, and a number of things have to be taken into consideration. Materials and conditions will be different on different homes, in different parts of North America, and at different times of the year.

Although these articles will give you the basics on which to build, you should make an effort to learn about materials and conditions you’re likely to encounter in the areas in which you work. Some of the important things to consider when you’re at the home site and have to decide whether or not to walk the roof are your own tolerance for risk, the roof pitch, the exposure, the condition of the roof-covering materials, and the equipment you have. Let’s take a look at each of these in more detail.

Risk Tolerance

Each year, people are injured or killed falling from roofs. In addition to the difficulty of finding a safe place to mount the roof is a fear of heights, which most people have, to some degree. For most people, confidence grows with experience, and they find that their fear of heights begins to fade as they spend more time walking roofs.

Your skills at walking roofs will improve on two different levels.

On one level, you’ll begin to develop a better understanding of what combinations of materials and conditions are safe.

On another level, you’ll have a better idea of the limitations of your own agility, including your sense of balance, your reaction time, and any limitations to your range of movement.

Fear creates tension in your body, and tension interferes with your sense of balance. Learning to relax while walking the roof will help improve your sense of balance.

Pitch

All other things being equal, steeper roofs are more dangerous to walk than flatter roofs, but even low-slope roofs can be dangerous.



Damp, moss-covered wood roofs and shingles, and especially metal roofs, can be slippery enough to cause you to slide right off even a low-slope roof.

So, the type of roof-covering material installed should be taken into consideration when looking at the pitch. For example, a roof with a pitch of 6&12 covered with asphalt shingles, on a warm day, might be relatively easy to walk, but a roof of the same pitch covered with smooth, metal roofing would be much more dangerous.

Typical Maximum Pitches Walked

Here are some examples of typical maximum pitches walked by inspectors who are comfortable on roofs:

• asphalt shingles: 8&12 for single-story homes, and 6&12 for two-story homes; • wood roofs: 6&12; and • metal roofs: 5&12.

Roof Boots

Special roof-walking boots and shoes with high-traction soles are available.




Exposure

In deciding whether or not to walk a roof, you’ll consider the exposure. The term "exposure," in this context, means the exposure to risk, or the additional danger represented by factors such as the height of the roof above the ground, and what you land on if you fall off the roof. Exposure for a three-story home built into a hillside would be much greater than the exposure for a single-story home.

Exposure for a home surrounded by a pointed, wrought-iron fence waiting to impale anyone falling off the roof would be higher than for one surrounded by a hedge which would help break their fall.

Roof-Covering Materials

When evaluating the safety of a roof, you also have to consider the condition of the roof-covering material. This includes both conditions related to weather, such as rain, snow or ice, and the overall condition of the roofing itself.

Moisture from rain or dew will affect different roof-covering materials to different degrees. Asphalt shingles provide a non-skid surface, even when they’re wet, unless they’re covered with microbial growth.

Bear in mind that moisture can disguise blemishes to the extent that either they can’t be found, or the characteristics become unclear, making the cause difficult to determine.

Wet metal roofing fastened by screws, except on very low-slope roofs, presents a hazardous situation. You’re probably going to slide off the roof and hit every screw head on your way to the edge. If there’s a gutter, when you leave, you may take it with you. You cannot depend on a gutter to keep you from going over the edge of a roof.

In deciding whether to walk the roof, you should also take into consideration the fragility of the roof-covering material. Asphalt shingles are fairly forgiving, unless they’re hot and new.

Tile condition varies with the type, and should not be walked, if it’s avoidable.

Slate should never be walked. Slate can have a powder-like surface that can be slippery even when it’s dry. It’s fragile when it’s old, and expensive to repair.

Wood roofs provide relatively good traction when they‘re dry, but can be very slippery when they’re wet, especially if they’re covered with biological growth.

Alternatives to Walking the Roof



There are roofs that, for one reason or another, you will not walk. Almost any roof can be examined from the rooftop but, sometimes, that examination requires measures that exceed the scope of the general home inspection.

When a roof has special inspection requirements, you may need to make arrangements to meet a roofing contractor at the property. This might be the case with an especially high roof needing a very long ladder. It might require placing ladders to climb especially steep roofs, or it might require fastening sheets of plywood across the surface of especially fragile roof-covering materials.

These measures exceed N.C. Storm Repair, LLC.'s Standards of Practice. The Standards specifically exempt inspectors from having to walk roofs at all, but many inspectors walk roofs anyway, both because they’re comfortable doing it and because they feel that it provides their clients with better service. It can also give them a business edge against any of their competition who don’t walk roofs.

The bottom line is: To perform a home inspection to the Standards of Practice, you are not obligated to walk a roof. You have alternatives.

You can examine the roof through binoculars from various points on the ground, or from the top of a ladder at the roof edge.

Some inspectors don't think they’re giving their client a full inspection unless they walk the roof. The fact is, you’re performing a general home inspection. In most situations, your inspection of the different home systems will not be as complete as a specialist inspection. Just as you won’t be pulling a furnace apart to get a good look at the heat exchanger, you won’t be laying tall ladders across very steep roofs, or suspending plywood across very fragile roofs. That’s a specialist inspection.

If you’re qualified, you can offer specialist inspections as ancillary services, but you should understand where to draw the line between what you provide in a general home inspection and what constitutes an ancillary inspection. If you are using methods and equipment that are usually used by a roofing contractor but not by a home inspector, you’re performing a specialist inspection.



This is one of the more unusual alternatives…

…a remote-controlled video camera mounted on a telescoping tripod.



The tripod extends up to 35 feet. Some are available that extend up to 70 feet.



When you’re finished, it folds up and rolls away.




GAINING ACCESS to the ROOF

Access by Window

Once you’ve decided to walk a roof, you'll have to decide how best to gain access. One way is by climbing out a window.

This can be the safest method, since it eliminates ladder-climbing, but you’ll need to be careful not to damage screens, walls or window trim.

You may also be able to access the roof from a deck or balcony, either by climbing over the rail onto an adjacent roof slope or by setting up a ladder.

LADDERS, Part 1

The typical method for accessing roofs is by a ladder resting on the ground and leaning against the edge of the roof. Finding a method for stabilizing ladders is highly advisable, since they become more unstable as you climb. One of the most common and

serious fall hazards you’ll face is stepping from the roof onto the ladder. Standing your ladder at an inside corner or against a wall will help provide a margin of safety.

Since it’s easy to scratch gutters, it’s a good idea to place your ladder in an inconspicuous location, if possible, such as at the side of the home, rather than at the front or the back. Your ladder should rest against an eave, and not a rake. If you have to choose between risking a gutter scratch or safety, choose safety.

Choosing a Ladder

In accessing roofs, the most important piece of equipment is your ladder. Most of the time, you’ll be accessing the roof with your ladder,



and the emphasis here is on “your” ladder. Never use a ladder you find on-site. You need to be familiar with the operation of the ladder you use to be sure that it’s in good condition. Never use a damaged ladder.

We’ll look at the different kinds of ladders and the situations in which they’re used, but a few rules are true no matter what ladder you use.

Read the label. You’ll be looking first at the load capacity. Ladders are generally rated as follows:

• Type I Industrial: These ladders are heavy-duty, with a load-capacity limit of 250 pounds.

• Type II Commercial: These ladders are medium-duty, with a load capacity of not more than 225 pounds.

• Type III Household: These ladders are light-duty, with a load-capacity maximum of 200 pounds. These are not appropriate for use during inspection work.

Some companies manufacture ladders rated for more weight than a Type I. Specialty ladders are available that are rated for up to 375 pounds.

As an inspector, your ladders are tools that you’ll use a lot. Low-quality ladders may be less expensive, but they’re not as sturdy, durable and safe as high-quality ladders. Always buy the best ladders you can afford.

You’ll be safer if you use ladders appropriate for each use.

Extension ladders are better for accessing roofs. Step-ladders are better for accessing attic hatches.



Safety Rules for All Ladders

These safety rules apply to all types of ladders:

• Keep it clean. Keep your ladders free of grease, oil, and other slip hazards.

• Don’t overload it. Never load a ladder beyond its labeled capacity.

• Beware of electrical dangers.

Never use metal ladders around exposed electrical wiring.

• Follow correct use. Use ladders only for their designed purpose. For example, don’t use a ladder as a scaffold plank.

• Ensure a stable setup. Make sure the ladder is stable before you climb it.

• Move it safely. Don’t try to move a ladder while you’re on it by rocking it or bouncing it. • Be healthy. Never use a ladder when you’re under the influence of alcohol, drugs or

medication, or when you don’t feel well. • If you must dismount unexpectedly, use good judgment and caution. If you get sick,

dizzy or panicky while on a ladder, don’t try to climb down in a hurry. Wait until you feel better, and then climb down slowly and carefully.




LADDERS, Part 2

Ladder Length

Extension ladders are a good choice when a ladder has to be leaned against a roof. They’re typically available in lengths from 16 feet to 40 feet, with choices in between in 4-foot increments. Ladder lengths are a personal choice.

Because extension ladders come in two parts which overlap, the length given is not the length of the ladder when it’s fully extended. For example, a 16-foot extension ladder has two 8-foot sections, but will only be 13 feet long when it’s fully extended.

Extension Ladder Material

Extension ladders are available in steel, aluminum and fiberglass.

• Fiberglass ladders are strong and don’t conduct electricity, but if stored outdoors, they will weather, especially in humid climates. A coat of lacquer or paste wax will help extend their service life.

• Steel ladders are strong, but they conduct electricity, so you’re at higher risk from shock or electrocution. If, while you’re standing on a steel ladder, you lose control and it comes into contact with overhead electrical wires, the result could be dangerous. Also, steel will corrode over time.

• Aluminum ladders are lightweight, but they’re generally not as strong and flex more than steel and fiberglass ladders. Aluminum ladders also conduct electricity.

• Wooden extension ladders are no longer common. They can be strong ladders if they’ve been well-maintained over the years. Look for cracks and loose rungs. Wooden ladders should have a finish coat applied to help prevent weather damage.

Standing an Extension Ladder

Trying to stand a tall extension ladder can be a challenge if you’re doing it alone. Here’s the proper way to stand an extension ladder:

1. Choose a level area on which the base will rest, once the ladder is stood.

2. Check overhead to make sure that the ladder will have plenty of clearance from any overhead wires.



3. While it’s still unextended, lay the ladder on the ground with the base against the bottom of the wall and the top pointing away from the wall.

4. Starting at the top of the ladder, lift the end over your head and walk under the ladder to the wall, moving your hands from rung to rung as you go.



When the ladder is vertical and the top is touching the roof, move the base of the ladder back a distance equal to about one-fourth of the distance from the ground to the point of support (usually, the gutter or fascia).

5. Ladders at too steep an angle are at increased risk of going over backwards as you climb. Ladders at too shallow an angle may overload the side rails, and the base of the ladder is more likely to slide as you climb. Once the ladder is stood, it can be extended as high as necessary.



The top of the ladder should extend at least 3 feet above the edge of the roof.

6. The ladder should be straight and secure. If the ladder leans to one side, place a firm material beneath the foot on the low side. If you dig holes in the lawn to adjust your ladder, the homeowner will not be running out the door to compliment you on your inventiveness. Don’t dig holes in the lawn.

7. If the ladder might slip, such as on a smooth concrete surface, brace the base of the ladder or use a non-skid mat. If you can’t make it safe, don’t climb the ladder.

8. Never set up or use a ladder in high wind, especially a lightweight-type. Wait until the air is calm enough to ensure safety.

9. Never set up a ladder in front of a door unless the door is safely locked or a guard is posted. You can hang a notice on the inside of the door. Do whatever is necessary to prevent someone from walking out the door and knocking loose the base of the ladder. It’s especially bad news if this happens while you’re on the ladder.



10. Tie off the ladder so that it can’t blow over (leaving you stranded on the roof), and to make it safer to mount and dismount from the roof. Conditions at the roof edge will be different on different homes; some homes have gutters, some have just fascia, so you’ll need to be inventive. Carry a variety of devices with you, such as clamps and bungee cords. Don’t depend on the tie-off connection to prevent the ladder from moving when you step onto and off of the roof. Don’t nail anything to the roof.

To take the ladder down, just reverse the process you used to stand it. Remember that you’ll be walking backwards, so check for obstacles in your path.

Shoes

Extension ladders have shoes that pivot so that the bottom of the shoe stays in contact with the surface, improving the ladder's stability on hard surfaces, such as concrete. Shoes often have rubber soles to better grip hard surfaces, and also to protect finishes on decks and balcony planking.

When pivoted all the way back, shoes lock into place with the sharp end down (called the spur), helping to prevent the base of the ladder from slipping.

Ladder Levelers Adjustable leg extensions are available for setting the ladder up on surfaces that are not level.

Documents

Roof inspection manual