Over the course of Haag’s 95 years in business, Haag has earned the reputation as the cream of the crop of failure and damage consultants. From our work on high profile jobs, to our innovative research and peer-reviewed papers, to our training and education, Haag has consistently been the standard bearer for quality and integrity in the failure and damage industry. The Haag Certified Inspector (HCI) programs are some of the most recent offerings impacting the industry we serve.
Since the early 1980s, Haag has taught hundreds of courses to thousands of adjusters and contractors. In 2007, Haag Education rolled out its first certification program for residential roof (steep slope) inspectors. Haag’s Certification programs tested and “certified” students on their comprehension and understanding of Haag’s damage assessment methods and principles.
In 2019, we are excited to also celebrate the 10th anniversary of our second Certified Inspector program on Commercial Roofs. The HCI-Commercial Roofs program was introduced in 2009 in response to industry demand following the success of HCI-Residential Roofs program. In 2014, Haag Education introduced our third certification on Wind Damage, which certifies those inspecting wind claims on anything related to building envelope from the foundation to roof covering.
Now, for the first time in the history of the Haag Certified Inspector program, Haag Education is happy to announce that industry professionals can now become Haag Certified online! Haag debuted our online version of the HCI-Residential Roofs certification in early February. Our customers are thrilled with the value and convenience of completing the entire HCI-R program from the comfort of their home or office!
Here are some important things to know about taking the HCI-R course online:
The introductory price for the course is only $599 (compared to $949 for classroom)
Students must have completed 100+ residential roof inspections to qualify for the HCI-R course (eligibility verification/references validated during registration).
Students completing the online HCI-R program will receive the same certification as those who take the course in the classroom.
Students have up to 30 days to complete the entire course and the test. (The course will take 12-14 hours to complete, and you are allowed up to 4 hours to take the final exam).
The final exam is administered by a third-party online proctoring company and can be completed from your home or office computer (webcam and audio required).
You will be provided a secure PDF of the course textbook. It may be viewed in an online viewer or it may be saved to your desktop.
Final exam is open book (online textbook may be referenced)
CE Credit is not yet available for the HCI-R online program. Applications pending.
Set yourself apart from the crowd. Join the ranks of the 18,000+ current Haag Certified Inspectors and become a more accurate, confident and efficient residential roof inspector by earning your Haag Certified Inspector – Residential Roofs certification online today! Now more convenient and less expensive than ever before! Visit www.haageducation.com/learn today.
–Ryan Holdhusen, Vice President of Haag Education Co.
Ryan Holdhusen oversees the management and strategic growth of Haag Education. He manages Haag’s line of seminars, certification programs, and products/tools. He assess product concept, development, marketing, sales and operations. Ryan has been with Haag since May 2002.
Way back in 1924, Walter G. Haag, a civil engineer who had graduated from Drexel Institute in Philadelphia in 1899, established his own consulting office in Dallas, Texas. He created Haag Engineering to determine facility values after losses (similar to the work Haag Construction Consulting performs today). Soon, clients began to ask Mr. Haag how the facilities were damaged. Thus, he began to perform engineering origin and cause evaluations. The term “forensic engineering” was not used back then. (In fact, Professional Engineer licensing wouldn’t even start until 1937.)
Mr. Haag hired Charles Wayne Parish in 1946. Mr. Parish, a World War II veteran and engineer in the Air Force, assumed increasing responsibility in the company and purchased it from Mr. Haag during 1956. Under Mr. Parish’s direction, Haag expanded its area of operation from North Texas to the world. He added Research & Testing capabilities in the early 1960s, which published a historic ice ball impacting study on wood roofing in 1963. Along the way, Haag Engineering has expanded to include Haag Construction Consulting, Haag Education, Haag Research & Testing, and Haag Technical Services.
As we celebrate Haag’s 95th anniversary in 2019, we thought it would be fun to take a look back at a few of the many noteworthy projects completed by Haag staff. During each month in 2019, this blog will feature noteworthy projects, as selected by our senior staff. We are fortunate to have several employees still with Haag who started in the 1970s, and one—my predecessor as Haag’s president & CEO, John Stewart (featured below)—who will be celebrating 50 years with Haag!
No company can endure, let alone prosper, for 95 years without talented, dedicated employees and loyal clients. Further, Haag would not have been able to prosper without a commitment to quality and integrity. As I like to say, we’re not good because we are old, we are old because we’re good. For turning 95, we still feel pretty spry!
Thank you to all the people who have contributed in any way to Haag’s pending 95th anniversary. That includes clients of our services and products, current and past employees, and all those who have spread a good word about Haag.
—Justin Kestner, P.E., President & CEO of Haag Global
Imperial Sugar- Sugar Dust Explosion
by John D. Stewart, P.E., Principal Engineer Emeritus
Around 7:00 am on February 7, 2008, a massive explosion occurred in the center of the Savannah Foods/Imperial Sugar facility, destroying or extensively damaging all three sugar silos and the packaging buildings that surrounded the silos. Sugar dust was believed to have been ignited by operating machinery. Many buildings outside the center of the plant also was extensively damaged. Investigations by government agencies as well as private experts concluded that the event was caused by an explosion of sugar dust followed by a fire wherein the sugar in the silos and throughout the area burned. Tragically, 14 individuals were killed in the blast and some 40 others were burned or injured.
Savannah Foods in Port Wentworth, Georgia, was founded in 1915 by Benjamin Alexander Oxnard and Richard H. Sprague when they moved their entire sugar refining operation, including more than 300 employees and their families, from St. Mary’s Parish in Louisiana to Port Wentworth. The refinery took in raw sugar and processed it into refined sugar and various other sugar products. The Savannah Sugar Refinery began melting sugar on July 7, 1917. In 1997, Imperial Sugar Corporation acquired Savannah Foods & Industries, Inc., which at the time was the second largest sugar refiner in the industry. Savannah Foods & Industries marketed its sugar under the Dixie Crystals® brand.
The Port Wentworth refinery included many large buildings, various tanks, and additional equipment for processing the sugar. Sugar was brought into the facility by ship and sent out by rail, truck, and ships. Among the facilities were three very large reinforced concrete silos located in the center of the packaging and storage area and used for storage of bulk refined sugar. These silos, constructed in 1935, were approximately 130 feet tall by 40 feet in diameter arranged in an east-west line and were capable of holding about 3 million pounds of sugar each. A large 4-story building to the north was the North Packaging Building. Another 4-story building to the south was the South Packaging Building. North and South Palletizing areas were to the west of the silos. The main refining and raw sugar storage facilities were east of the silos. Other buildings were south of the silo/packaging area.
Above, a 2008 image after the explosion and a 2019 oblique image of the same area. The centers of both images cover most of the areas of major damage.
Following the February 2008 explosion, Haag engineers were engaged by the insurers to evaluate the scope of damage and cost of repairs to the facility resulting from the event. Haag also monitored the repair work during the several year period of restoration. Haag’s role beyond evaluation of the scope of damage was to monitor and separate extensive upgrades of the rebuilt facility from needed repairs. The extensive upgrades of the facility took it from an old processing unit to a state-of-the-art processing and packaging plant.
Haag engineers were on site from shortly after the explosion until the repairs were completed and the plant restarted in late 2009. Haag was closely involved in the evaluation of the scope of damage. Knowing that the facility would be extensively modified during the restoration it was critical to prepare a detailed scope of work including estimates of repairs for facilities that would not be rebuilt in kind. Haag also was closely involved in all discussions about all changes, extensive upgrades, and reconfigurations of the facility to ensure that costs charged to the insurers of the facility were fair and represented the costs to restore an equivalent facility despite the many changes.
Ultimately, the loss cost insurers approx. $345 million out of total insurance coverage of $350 million. Total of physical damage and business interruption well exceeded $500 million.
John D. Stewart, P.E., is Principal Engineer Emeritus at Haag Engineering Co. and served as Haag’s President for more than 30 years (1982 – 2014). Mr. Stewart has been with Haag Engineering Co. since 1969. His engineering expertise includes evaluating and determining the scope of damage and repair options following failures, including at industrial plants, oil refineries, chemical plants. He has analyzed electrical failures, lightning damage, and electronic and computer equipment failures.
Mr. Stewart graduated from the University of Texas at Arlington with a Bachelor of Science degree in Electrical Engineering. He is a licensed professional engineer in the states of Texas and Arizona, and a member of the Institute of Electrical and Electronic Engineers (IEEE), the American Institute of Chemical Engineers (AIChE), the National Fire Protection Association (NFPA), the International Association of Arson Investigators (IAAI), the National Society of Professional Engineers (NSPE), and the Texas Society of Professional Engineers.
Aerial Lifts—now called Mobile Elevating Work Platforms (or MEWPs)—provide a safe way for viewing parts of a roof or building envelope. They can help you safely access elevated parts of structures. Haag’s resident MEWP expert, Anthony Bond, P.E., breaks down the types, components and uses of lifts.
Aerial devices have a variety of names given to them throughout the years. Common names for aerial devices include Cherry Pickers, Man Lifts, Bucket Trucks, Aerial Lifts, Aerial Work Platforms (AWP), and Elevating Work Platforms (EWP). The new American National Standards Institute (ANSI) group of standards (A92.20, A92.22, and A92.24) name these aerial devices Mobile Elevating Work Platforms. The definition provided by the new ANSI standards for Mobile Elevating Work Platforms or MEWPs is a “machine/device intended for moving persons, tools, and material to work positions, consisting of at least a work platform with controls, and extending structure and a chassis”.
There are several different types of MEWPs including truck-mounted aerial devices, trailer-mounted aerial devices, boom lifts, scissor lifts, and bridge inspection/maintenance devices. The typical types of MEWPs that we see on construction sites are scissor lifts (Group A, Type 3) and boom lifts (Group B, Type 3). Group A are MEWPs with platforms that move vertically, and stay inside the tippling lines. Group B are all the other type MEWPs with platforms that extends past the machine’s chassis. Type 1 MEWPs can only be driven in the stowed position, and Type 2 MEWPs can be driven with the platform elevated from a point on the chassis. While Type 3 MEWPs can be driven with the platform elevated from the chassis.
MEWPs have three basic assemblies: chassis, extending structure, and platform. For boom lifts, the extending structure is a boom assembly that either telescopes, articulates, or a combination of the two. Booms lifts are raised via a lift cylinder and extends by an internal cylinder, sometimes aided by wire ropes or chains. Boom lifts have an extending structure (typically boom-type) that positions the platform outward and upward beyond the chassis. While scissor lifts have an extending structure or scissor mechanism that elevates the platform vertically via a lift cylinder.
In order to select the type of MEWP for a specific job, some features of the MEWP to consider include its platform height, platform reach, platform capacity, working envelope, turning radius, and machine weight, as well as the MEWP’s overall dimensions. Platform height is the vertical distance from the ground (surface that the MEWP is on) to the floor of the platform. Platform reach is the horizontal distance from the center of rotation to the outboard railing of the platform. Platform capacity is the rated load that the platform can carry, which includes the total weight of the operator, tools, materials, and anything else that is within the platform that is not originally part of the MEWP. Working envelope is the operating range that the boom/platform maneuvers within as designed. This is usually illustrated by a range or reach diagram. Turning radius is the smallest circle that the MEWP can make. Scissor lifts typically have a smaller turning radius than boom lifts. Machine weight is the weight of the machine as configured by the manufacturer. Scissor lifts are typically less than 6,000 pounds, while boom lifts can weigh as much as 50,000 pounds or more. The overall dimensions of MEWPs vary tremendously. A 150-foot boom lift is approximately 40 feet long, 10 feet tall, and over 16 feet wide with its axles extended. Whereas a 20-foot scissor lift is approximately 8 feet long, 7 feet tall, and 3 feet wide.
Performing a worksite inspection will determine the required characteristics for the MEWP, while keeping in mind the limitations and restrictions of the worksite. Worksite limitations and restrictions can include overhead obstructions such as power lines that require minimum safe distances, height/width restrictions caused by the route the MEWP must travel, limits to safe travel for the MEWP due to hazards such as surface conditions (unlevel surfaces such as ramps, depressions, drop-offs, or holes), and surfaces that cannot support the weight of the MEWP (sidewalks, vaults or enclosures below ground).
Training requirements for MEWPs (aerial lifts) are provided within OSHA regulations. OSHA requires that, “Only trained and authorized persons are allowed to operate an aerial lift.” OSHA’s Fact Sheet for Aerial Lifts indicates that training include the following: “Explanations of electrical, fall, and falling object hazards; Procedures for dealing with hazards; Recognizing and avoiding unsafe conditions in the work setting; Instructions for correct operation of the lift (including maximum intended load and load capacity); Demonstrations of the skills and knowledge needed to operate an aerial lift before operating it on the job; When and how to perform inspections; and Manufacturer’s requirements.”
When safely operated by trained professionals, using Mobile Elevating Work Platforms/Aerial Lifts will help make your job safer.
Anthony E. Bond, P.E., is a Principal Engineer and aerial device expert. Mr. Bond has been with Haag for more than 10 years, and has 25 years of active involvement in the aerial device industry. He specializes in determining the cause and extent of aerial device accidents and responsibilities of involved parties (manufacturer, owner, dealer, user, operator) as defined by aerial device national consensus standards. He testifies in depositions and trials as an aerial device and crane expert. Mr. Bond gained valuable experience from his employment as a design engineer and engineering manager for an aerial device and crane manufacturing company. His structural designs and analyses include booms, pedestals, carriers, and outriggers, as well as hydraulic cylinders. Designs also include hydraulic, electrical, and control systems for product development of aerial devices. Under his direction as an engineer manager, the research and development team fabricated and assembled prototype models for testing prior to releasing new aerial device models for production. He is a licensed Professional Engineer in 26 states, and a member of the American Institute of Steel Construction (AISC), American Society of Mechanical Engineers (ASME), National Society of Professional Engineers (NSPE), Society of Automotive Engineers (SAE), and Scaffold Industry Association (SIA).
Seen and Unseen….The Benefits of Desaturation Testing
By Steve R. Smith P.E.
Have you ever been examining a built-up roof and encountered a mark which was not easy to identify? Identification of hail-caused damage to a roof can be as simple as following standard hail inspection procedures. Look for hail spatter and dents in soft metals. Examine less well supported components and examine test areas on the roof (a procedure developed by Haag Engineering Co. in the 1970s).
Sometimes, however, there are conditions observed on the surface of the roof that appear similar to a hail-caused condition but may or may not be related to hail. Also, it is not uncommon for two separate parties to have differing opinions on whether or not a hail-caused condition has compromised the roof covering.
When you find questionable marks on a roof, desaturation analysis of roofing samples can provide invaluable information. Desaturation can help determine if a particular feature is hail-caused and if the water-shedding ability or long-term service life of a roof has been compromised. Haag Engineering’s laboratory, established in 1963, has been performing desaturation analysis on roofing samples for decades. Desaturation can determine conclusively if a bituminous roofing sample has been compromised by hail.
Desaturation works like this: lab personnel use equipment and chemicals to extract the reinforcements from asphalt built-up roofing (ABUR), coal tar built-up roofing (CTBUR), modified bitumen membranes (mod-bit), asphalt roll roofing, and asphalt shingles. Then, they examine the reinforcements to identify fractures, or the absence of fractures, and determine if the fractures present are characteristic of damage associated with hailstone impacts. Desaturation can also help identify the constituents of a roof, including the number of roofing plies, the types of roofing plies, and the quantity (weight) of the inter-ply asphalt.
Haag’s lab examined an ABUR sample for the effects of hail, see photos below. When the bitumen was removed, our analysis revealed fiberglass reinforcements from the ABUR system, and several organic reinforcements from the previous roof system that was left in place and overlaid. There were no hail-caused fractures in the fiberglass reinforcements, but a hole was observed in one of the organic plies. We noted the hole was only present in the uppermost organic ply, which is not consistent with an impact-caused fracture. Instead, the hole was characteristic of a weathering-related condition in the older roof system.
Figure 1: Desaturation of ABUR – fiberglass and organic reinforcements
ABUR prior to desaturation
ABUR after desaturation showing
fiberglass reinforcement
Organic reinforcement was found
several piles down, revealing a hole
Hole was found in the uppermost organic ply only
Organic ply below the top organicply did not contain a hole,indicating the hole was a weathered condition on the oldroof, rather than an inpact-caused fracture
Now let’s look at a mod-bit sample. This sample exhibited a discrete region of missing granules that was thought by some to be a hail-caused bruise. There were no fractures visible in the top or bottom surfaces of the sample prior to desaturation. We noted the exact location of the area of interest so that we could examine the same area after desaturation, which revealed the reinforcement was intact.
Figure 2: Desaturation of mod-bit – scrim-type reinforcement
Mod-bit prior to desaturation
Area of interest observed on
the top surface
Scrim-type reinforcement extracted by desautration
Close-up of reinforcement at the area of interest revealed no damage to the reinforcement (the structural element of the roof)
Finally, let’s examine a mod-bit sample that shows the effects of impact by large hail. Our laboratory personnel installed a mod-bit sample on a test panel to replicate the as-installed support conditions for the sample and performed ice ball impact testing to show the effects of hail impact. The sample was impacted by three ice balls, ranging up to two inches in diameter. The two-inch diameter impact is highlighted in blue (Figure 3). Desaturation of the sample revealed a fracture at the two-inch diameter impact location.
Figure 3: Desaturation of mod-bit impacted by ice balls – polyester reinforcement
Mod-bit prior to desaturation
Impact testing setup
Sample after impact testing
Sample after desaturation (top side up)
Bottom side of reinforcement
after desaturation
Close-up at fracture caused by a
2-inch diameter ice ball impact
In all examples, desaturation was able to conclusively determine if the reinforcements had been fractured by hail. Desaturation also allowed us to identify constituent components and even provided insight on the condition of the previous roof system (Figure 1). Hail-fractured reinforcements ultimately result in a loss of water-shedding ability and/or reduction of the remaining service life of the roof. Knowing if the structural components of a roof had been compromised by hail is paramount in determining appropriate remediation procedures.
Since desaturation is destructive testing, Haag Research and Testing personnel carefully document test specimens during all phases of testing. We photograph and even video record (if requested) to document specimen conditions and preserve the evidence. Proper maintenance of the chain of custody of evidence is another important consideration.
Steve R. Smith P.E. is the Director of Research & Testing. Mr. Smith is based at Haag’s national headquarters in Flower Mound, TX, and can be reached at ssmith@haagglobal.com .
All shallow foundations in contact with clay soil will experience some degree of movement, usually seasonally, and an owner should recognize that complete isolation from the effects of clay is generally not practical or affordable. Some degree of movement is accepted by most owners, and the strategies chosen to limit that movement are a function of the owner’s sensitivity to cosmetic cracks, building use, and cost. Differential movement does not reduce the structural capacity of the foundation. The floor and foundation simply are not level. If an owner does not mind the existing condition of their house, foundation repairs are not required.
When repairs are performed, the most common method is to add pier supports under the foundation. The greatest movement is typically from seasonal shrink/swell of the clay, and it manifests at the perimeter. Stabilizing the house with added supports along the perimeter is the most cost-effective method of repair. Any pier type will work. A house is so lightly loaded that any of the commercially available systems will support the weight. The primary consideration should be depth. The added piers should be deep enough that they support the house on soil that will not be dried and wetted seasonally.
Engineers typically specify repair piers to be around 15 feet deep when trying to economically extend below the zone of seasonal moisture change. Additional depth may offer added protection against drying by large trees. The number of piers needed to reduce perimeter movement depends on the owner. An owner can choose to add supports to the areas that concern them and hope the other parts of the house continue to perform satisfactorily (partial piering) or an owner can choose to add supports around the entire perimeter all at once. Regardless, the floor can be lifted once the piers are installed, but it is highly unlikely that a contractor will be able to return the floor to level. About 1-inch of difference is normal for even a new house, and once a floor has distorted, restoring the level shape is usually impractical. (The wood framing will have essentially warped into the distorted shape.) The owner should discuss lifting, potential damage to plumbing, and any grouting of voids left under a slab by lifting it.
Finally, an owner should understand that the house still rests on clay soil and can move seasonally in the future. The piered areas will likely not settle much unless there is a severe drought that affects the deep soil, but they can still be lifted upward off the piers when the soil takes on water and heaves. For this reason, we believe it makes sense to wait until the wet season to install piers so that the house is underpinned at close to its highest level. When large trees grow close to the house, they often establish roots under it, and those roots can be cut to reduce the possibility that the interior slab will settle during dry weather, leaving the perimeter perched on piers.
Hail Yes or Hail No: Was the Metal Roof Really Damaged by Hail?
By Justin Kestner, P.E.
Disagreement over whether a roof has been damaged by hail is not a new issue. However, the past several years have seen a dramatic increase in the number of hail claims that have been filed.
From an engineering perspective, hail with sufficient mass, hardness, and impact energy can dent or rupture (tear) metal roofing materials. Haag Engineering began its ice ball impact testing program for roofing in 1963. Haag’s impact testing of metal panels in good to fair condition has demonstrated that the typical threshold size for hail necessary to rupture metal panels in good to fair condition is at least 2.5 inches. This testing involved perpendicular impacts of frozen solid ice balls—a worst-case scenario—traveling at their freefall velocities.
Hail-caused distortions along panel seams can cause openings that allow water intrusion. Hail impacts at fasteners in unsupported seams can sometimes disengage these fasteners. Ruptured panels, disengaged fasteners, and openings along seams have been considered damage to metal roofing because the water-shedding capability had been compromised. Removal of protective coatings by hail (again, typically field-applied coatings) also occurs on occasion from hail impacts and has been considered damage to metal roofing as the service life of the roof would be reduced. The question that arises in these situations is the appropriate method of repair or replacement.
Dents, dimples and dings that do not disengage panels or fasteners or disrupt protective surface coatings do not diminish the roof’s ability to shed water or reduce its expected useful service life. Yet, such conditions may be considered “damage” under certain insurance policies.
Engineers and roofing consultants are not adjusters and should remain focused in their investigations on the evidence they see at the site. Any inspection of a metal roof must focus on the basics. First, did hail fall at the site? Second, if hail fell at the site, when did it occur? Third, the size of hail that fell at the site should be documented along with the directionality of the storm(s), and if possible, a determination should be made regarding whether or not the property was impacted by multiple hailstorms. This can be accomplished by assessing spatter marks (where hail removes oxidation and grime) and dents on various surfaces including roofing materials, roof appurtenances, fencing, utility boxes, and claddings. Hail typically falls in a defined direction. Thus, one or two sides of a roof typically bear the brunt of a storm. If more than two vertical surfaces of a building are affected, this could indicate that multiple storms impacted the property. Spatter marks will fade with time and may last up to two years depending on exposure and other factors.
Engineers and roof consultants typically focus on what hail did and did not do when evaluating a property. For instance, they should note if the hail impacts dented roofing panels and to what extent. If inspecting experts find dented panels, then they should then determine whether this has adversely affected the useful life or the water shedding capability of the roof. This is accomplished by determining if impacts caused panel ruptures, disengaged fasteners, or caused openings along panel seams. If there is evidence of hail-caused openings, the expert may be asked to determine if this has caused any interior water damage. Further examination may include searching for dented roof appurtenances; dented or fractured siding and/or window trim; broken windows; dented gutters and downspouts; dented overhead or man doors; etc. Other considerations include separating mechanically-caused conditions from hail impacts. For example, dents with scratches in them are indicative of mechanical impact rather than hail impact, as hail is not hard enough to scratch metal. Further, disproportionately large and/or deep dents relative to the size of hail that fell in the area may be indicative of foot traffic or some other cause rather than hail.
Engineers and roof consultants are hired to document their observations and render opinions based on their expertise. They do not make coverage decisions because that is always the role of the insurance claims professional. As a result, it is critically important that the claims professional consult with the engineer or roof consultant at the early stage of the claim, so that the expert’s report provides sufficient information for the claims professional to make the proper decisions based upon what is considered “damage” in the applicable insurance policy. This is where having a clearly defined scope of work can benefit both parties.
Once damage is determined to exist, reparability of metal roofs can be a complex issue and may require estimates from construction consultants or roofing contractors. Questions sometimes arise regarding whether or not dents have adversely strained the metal. If a dispute lingers over this issue, dented samples of the roof could be removed by a qualified roofer and inspected by a qualified engineer or laboratory professional.
Dating the approximate time frame of a storm can also be important. In this situation, the engineer should check weather records and inspect the roof for spatter marks coincident with dents to determine if the dents were from a recent storm. Weather service reports by third parties are another tool that can be utilized. An engineer should always look at the weather service reports in conjunction with what can be supported and documented by site conditions.
This is excerpted from “Testing Your Mettle”, which originally appeared in The CLM. The article was co-authored by Kevin Kennedy, esquire. The full article can be found by clicking here.
Justin Kestner, P.E. President and CEO, Haag Engineering
Justin Kestner graduated from Villanova University with a Bachelor of Science degree in Civil Engineering. He earned a Master of Science degree from Lehigh University in Civil Engineerning, where he focused on structural engineering. Mr. Kestner also has a Master of Business Administration degree from Villanova. He is licensed as a professional engineer in 17 states. Mr. Kestner currently serves as the President and CEO of Haag Engineering, as well as a Principal Engineer. He is a member of the American Society of Civil Engineers, Phi Kappa Phi National Honor Society, the loss Executives Association, the National Council of Examiners for Engineering and Surveying, and the Fritz Engineering Research Society. Mr. Kestner has been with Haag Engineering since January 2006. See his profile here.
In this post we talk about “The Brittleness Test.” However, before delving into the specific discussion of “The Brittleness Test,” it is important to first understand how industry-accepted test methods are developed so we can ask – Is “The Brittleness Test” an industry-accepted test method?
Industry-Accepted Test Methods
Consensus Test Methods:
Testing organizations frequently develop and issue testing procedures for building materials. Typically, the way such procedures are conceived is through a technical committee within the organization. These technical committees are open to the public, comprised of stakeholders in the industry, and are typically volunteers. For the example of roofing materials, representatives from manufacturing, insurance, those who represent property owners, contractors, engineers, scientists from research facilities, and representatives from trade organizations, among others, could make up the members of the committee. The committee then assigns different sections of the standard as well as research, to be written or undertaken by the different members. The draft standard is then iteratively submitted to the rest of the committee for comments, edits, and suggestions, until a final version is prepared and balloted. Organizations such as ASTM and ANSI generally publish testing procedures in this fashion. More information on ASTM and ANSI test standard development can be found at the following links, respectively:
Another way to publish scientific methodology is through an academic journal. This is typically referred to as a peer-reviewed publication. The peer-review process begins with scientists observing, studying, and qualifying or quantifying the phenomenon. These scientists then complete their analysis and write an article on their results. The article is submitted to the editor of a relevant journal. In the case of building science, articles can be submitted to the journals of Building and Environment, Construction and Building Materials, Materials and Structures, Building Research and Information, or Materials in Civil Engineering, among many, many others. The editor of the journal would then send the article to other well-known scientists, in the same field, for their review. These peer reviewers read the article and provide feedback to the editor. At this stage, the editor can compile a list of comments for the authors or if the article doesn’t meet the scientific standards of the journal, it can be rejected. If the article is not rejected, the authors then answer reviewer’s questions and comments, revise the document, and resubmit for further review. The process iterates until the peer reviewers and editor are satisfied the scientific standards of the journal are met and the article is published in that journal.
These two ways in which testing methods or procedures are published are important because it shows that procedures have been reviewed by an established and rigorous process by stakeholders in the industry—the same entities that will use the procedures. Further, these processes assure the reduction of bias by any one branch of the industry because it was compiled by members of the different branches of the industry or it was reviewed by different members of the industry. In effect, it serves as a checks and balances system.
So, what is “The Brittleness Test”?
Many in the industry refer to “The Brittleness Test” as a method by which the reparability of an asphalt composition shingle roof can be assessed; however, is “The Brittleness Test” that you’ve encountered an industry-accepted test method, as outlined above?
The answer is likely, no. There is a widespread misconception that there is a prescribed methodology to “The Brittleness Test”. There is no ASTM, ANSI, Haag, or other industry-accepted, peer-reviewed method to determine or quantify shingle brittleness. But why is this important?
Let’s examine what some inspectors refer to as “The Brittleness Test.”
Lifting the shingle X-inches
Some inspectors refer to “The Brittleness Test” as un-bonding a field shingle and lifting the end of the shingle until it is X-inches above the roof surface. However, the lifting force is not specified and rarely is the lifting dimension justified. It is clear that without limiting the lifting force or justifying the significance of the lifting dimension, such a method can be misused.
We often come across inspectors that will specify the lift dimension as a dimension equal or greater to 6 inches. In looking at a proper shingle installation, typical nail locations for a three-tab shingle are 5-5/8 inches and for some laminated shingles can be less than 6 inches. Specifying a lift dimension of 6 inches or greater, can result in tearing of the shingle around the fasteners, without having anything to do with the age/condition of the shingle. Figure 1 below shows an example of lifting a tab straight up without causing damage. Its end measured less than 5 inches above the roof.
Figure 1 – Lifting a shingle tab without causing damage measured less than 5 inches.
Bending the shingle to X-degrees
Some inspectors refer to “The Brittleness Test” as un-bonding a field shingle and bending it to a certain angle. However, the lifting force is not specified and rarely is the lift angle justified. Further, rarely is care given to the radius of curvature of the shingle. For example, inspectors often refer to 90 degrees as is shown in Figure 2 below:
Figure 2 – An illustration of “The Brittleness Test” where a shingle corner is bend upward to a 90-degree bend. Note the difference in the two radii of curvature.
It is clear how a tight radius of curvature, as is shown on the left, is more likely to damage the material (this could happen when bending the shingle against the overlying shingle or against its fasteners), regardless of its age/condition when compared to the example on the right (without the shingle binding on the overlying shingle or its fasteners). Figure 3 is an example of a 90-degree bend, with a tight radius of curvature, causing damage to a new three-tab composition shingle.
Figure 3 – “The Brittleness Test” 90-degree bend causing damage to a brand new, unweathered shingle.
It is also clear that a 90-degree bend is not necessary to access the shingle’s fasteners.
Pinching the shingle corner:
More recently, we have encountered inspectors who claim that “The Brittleness Test” is the pinching of the shingle corner. In effect, the test they employ is bending a shingle corner against itself (180 degrees) and pressing down on the crease as is shown in the diagram below:
Figure 4 – An illustration of “The Brittleness Test” where a shingle corner is pinched.
It is clear that such a test could cause damage to any shingle regardless of its age/condition. Such a bend is not necessary in conducting an individual shingle replacement. As such, it is unclear how such a test is related to reparability. Below is an example of this test causing damage to a new three-tab composition shingle.
Figure 5 – “The Brittleness Test” corner pinch causing damage to a brand new, unweathered shingle.
These are the most common “Brittleness Tests” other inspectors have reported or shown to us; however, the list of other “Brittleness Tests” with different failure criteria goes on and on. This conversation could further be expanded when considering the effect temperature has on the shingles. However, being that there is no industry-accepted, peer-reviewed, step-by-step, quality-controlled methodology, we cannot assure that performing “The Brittleness Test” can be accomplished in a repeatable scientific way. It is clear that the lack of specificity, procedure, consistency, and repeatability in these methods can lead to biased results.
If there is no “Brittleness Test,” how do you determine reparability?
Assessing the reparability of a shingle involves determining whether the fasteners can be accessed without causing damage to the overlying shingle; however, can this be accomplished without an industry-accepted test method?
Legitimate concerns regarding reparability can be addressed by attempting to remove and replace a shingle. First and foremost, permission of the property owner should be obtained. Then, the target shingle and the shingle directly upslope can be carefully unbonded, the fasteners for the target shingle and the shingle directly upslope can be removed, and the target shingle removed. The adjacent shingles (not the removed shingle) can then be closely inspected for damage.
In using this method, however, be cautious of purposeful efforts by others to damage the roofing. Figure 6 is of an instance where one of our engineers encountered another inspector that attempted to demonstrate the shingle’s “brittleness”. The inspector attempted to demonstrate removing a shingle while lifting his pry-bar straight up to pry out a nail, clearly causing damage.
Figure 6 – An example of purposeful efforts by others to damage the roofing.
Another method to determine the reparability of a shingle could be to carefully un-bond a shingle or find an intact non-bonded shingle, then carefully lifting the shingle enough to expose the fasteners and release the shingle. Upon release, the lifted shingle can be inspected for damage. Any shingles that were unbonded for examination should also be resealed with quarter-sized dollops of roofing cement. Figure 7 illustrates this procedure in a case where shingles lay flush on the roof without having incurred any damage.
Figure 7 – Documentation of a shingle before lifting, lifting enough to expose fasteners, and release, and after releasing the shingles showing they sat flush without having incurred any damage.
It is clear that for either of the two presented methods to determine reparability, discretion and good judgement are necessary. Both are not only necessary in determining reparability, but if the shingles are determined to be repairable, accounting for the difficulty of the repairs.
Carlos Lopez, Ph.D., P.E., Haag Engineer
Carlos graduated from the UN of FL with a BS, MS, and Ph.D. in Civil Engineering. He is a member of the American Association for Wind Engineering, the American Society of Civil Engineering, and the American Concrete Institute. Carlos has assessed damage to hundreds of roofs since joining Haag in 2012. He also served as a key developer of the Haag Certified Inspector-Wind Damage Course. His primary areas of consulting are structural evaluations and general damage assessment. He also works in the Haag Research/Testing laboratory, designing new test apparatuses and performing experiments and industry-accepted testing procedures.
Any opinions expressed herein are those of the author(s) and do not necessarily reflect those of Haag Global, Inc., Haag Canada, or any Haag companies.
Identifying HAIL-CAUSED FRACTURES IN THERMOPLASTIC ROOFING
In most roof systems, hail-caused damage is readily identifiable, but in other systems, such as single-ply thermoplastic roofing, the damage initially can be less apparent. Imagine this scenario: a severe thunderstorm deposits hail at a commercial property. There is immediate concern that the single-ply roofing membrane had been damaged by hail. An inspection of the roof reveals spatter marks (areas of grime and oxide cleaned from surfaces struck by hailstones) and dents in metals confirming that hail had fallen at the property. The membrane is examined and the plastic single-ply is determined as not damaged. A few months later, several leaks are discovered after a heavy rain storm, prompting a follow-up roof inspection. Hail-caused fractures are discovered throughout the membrane during the second inspection. What likely happened?
Depending on the type of roof system, hail-caused damage takes different forms. Hail-caused fractures in thermoplastic roofing range from circular to semi-circular to multiple fractures in circular patterns. Frequently, the fractures are especially “tight” after hailstone impacts. Over time, the membrane “relaxes” due to the effects of weathering, and the fractures accumulate grime making the fractures more apparent. The impact-caused fractures may not be visible to the naked eye immediately after they originate, but proper inspection techniques will aid us in identifying hail-caused damage on our first inspection visit.
First, we need to know where the thermoplastic membrane is most likely to be damaged by hail. The membrane is most sensitive to impact damage at the edges of underlying steel stress plates (washers). Depending on the roofing application, these may be found within lap seams and atop the insulation immediately below the membrane. The next areas most sensitive to damage are those not solidly supported: commonly base flashing at parapet walls and curbs. Lastly, consider membrane in the field of the roof, especially where underlying insulation boards have wide gaps or are uneven. Importantly, thermoplastic membranes become more brittle with age and therefore more impact sensitive. Sometimes brittle sections correspond to roofing areas that regularly pond water, as this prolonged contact accelerates the aging process.
Second, we will identify locations where the membrane had been struck by hail. Normally, a thin layer of grime has accumulated on the roof. Hailstones that impact the roof clean away this surface grime, leaving a spatter mark. In general, larger or softer hail creates larger spatter marks than smaller or harder hail. Note that thermoplastic roofing typically is installed over rigid foam insulation. Impacts by large hail can dent the insulation. For this reason, even when spatter marks are not visible, we can locate impact sites by feeling dents in the insulation.
Now that we know where to look and what to look for, we can examine the roof for hail-caused fractures. Once an impact location is found (whether indicated by a spatter mark, a dent, or both), we can examine the membrane for a fracture. If a fracture is not visible, rub the impact with your fingers to force grime into the fracture (if one exists). Larger areas measuring a few square feet can similarly be rubbed by hand, providing larger areas to examine. If no fractures are observed within a test area, one could consider rubbing the entire test area by hand, providing an additional opportunity to locate hail-caused fractures.
There also are instances where an inspection might reveal hail-caused fractures from a storm that occurred long ago. Old fractures have been exposed to the weather longer than more recent fractures, and hence, they tend to exhibit the following characteristics: their edges are generally more round, they are darker in color, and they are generally wider. In some cases, readily visible hail-caused fractures are observed on the roof, yet none align with spatter marks, which would clearly indicate that the fractures were not the result of the recent hailstorm.
The use of these techniques will aid an inspector in determining if a thermoplastic roofing membrane had been damaged by hail and whether the damage had occurred recently or if the damage was created long ago. Understanding where to look, what to look for, and how to detect hail-caused damage to thermoplastic roofing is critical in making a proper analysis.
Steve R. Smith, P.E. and Haag Senior Engineer Steve Smith completed nuclear power training with the United States Navy in 1994. He was honorably discharged in 1998 and went to work for Haag Engineering Co. as Senior Laboratory Technician. Steve has performed hundreds of hail impact tests on a variety of products including roofing, siding, and automobiles. He graduated from the University of Texas at Arlington in 2005 with a Bachelor’s degree in Mechanical Engineering and is a member of the American Society of Mechanical Engineers, the Society of Automotive Engineers, and the National Association of Fire Investigators. Steve has inspected and assessed damage to a number of roof systems, including single-ply systems, composition shingles, cedar shake and shingles, concrete tiles, slates, and built-up roofing. See his full profile here.
Scrim-type reinforcement extracted by desautration
