Month: March 2022

Haag Welcomes John Thomazin, MSME, P.E., DFE, Forensic Engineer!

“We are very pleased to welcome John Thomazin to Haag,” said Justin Kestner, Haag Global CEO. “John brings 25+ years of engineering experience to Haag. He has a great mix of design and forensic experience, including as an expert witness.”

Based in Orlando, Florida, John Thomazin, MSME, P.E., provides mechanical and electrical systems consulting in the fields of manufacturing, safety engineering, structural and mechanical design, reliability, computer-aided engineering, consulting, and project management.

Mr. Thomazin specializes in vehicle accident reconstruction, farm accidents, structural systems, mechanical systems, product liability, failure analysis, and finite element modeling. As an engineering consultant, he has experience designing and evaluating agricultural buildings, commercial buildings, metal buildings and structures, foundations, agricultural and commercial machinery, HVAC, and plumbing systems. He applies principles of engineering and physics to the forensic evaluation of machinery, crash investigation and reconstruction, and consumer products.

Since 2008, Mr. Thomazin has been retained by both plaintiff and defense clients and has provided testimony for civil cases in state and federal jurisdictions. He uses his skills and experience gained as an instructor and project manager to explain and simplify technical ideas while also keeping testimony relatable, memorable, and interesting.

Primary Areas of Consulting

  • Vehicle Accident Reconstruction
  • Products Liability
  • Equipment & Machinery
  • Mechanical & Agricultural Engineering
  • Failure Analysis
  • Safety Engineering
  • Manufacturing
  • Mathematics
  • Building Inspections
  • Construction Defects
  • HVAC
  • Plumbing Passenger & Freight Elevators

For more information or to contact Mr. Thomazin, please see his profile here. 

Haag Canada Announces New Managing Director, Derek Sayers

Haag is pleased to announce the promotion of Derek Sayers, MRICS, MSCL, MIIC, to Managing Director of Haag Canada. Mr. Sayers will leverage his expertise and leadership skills to serve Haag’s clients and expand the market reach of Haag Canada.

“Haag has built a reputation for our relentless pursuit of excellence,” said Justin Kestner, MSCE, MBA, P.E., CEO of Haag Global. “Derek Sayers will lead Haag Canada with our shared commitment to professionalism, quality, and integrity. Derek has a keen attention to detail and organization which will benefit our Canadian clients while growing our reach and reputation from coast-to-coast.”

During his 30+ year career as a construction claims professional, Mr. Sayers has handled large and complex construction claims, both domestically and internationally. He has served as quantum expert, project contracts manager, and corporate claims manager. He has diversified Haag Canada’s client base, building solid and enduring relationships with owners, lawyers, and contractors across the country.  Mr. Sayers will use that experience to enrich and grow Haag Canada and will continue to serve as Practice Lead for Construction Claims.

Haag Canada accurately determines and clearly communicates cause, quantum, and mitigation of loss to help clients make difficult decisions with confidence. Catering to the growing complexity of client needs in Canada the firm provides a national resource of core services, including forensic engineering, loss remediation and mitigation, physical damage quantification and appraisal, and risk and project management. Haag Canada draws on Haag’s team of international experts and 98-year legacy of handling complex losses in the most insured and litigious markets in the world.

For more information on Haag Canada or to contact a representative, please visit

Haag Canada
401 Bay Street, 16th Floor
Toronto, ON M5H 2Y4
800-527-0168 (Toll Free)
416-917-4141 (Main)

About Haag Global

Haag Global, Inc., began as a failure and damage consulting firm in 1924. Today, Haag is an employee-owned, multi-faceted forensic engineering and consulting company. Haag is the United States’ oldest and most respected failure and damage consulting firm, with a 98-year history of engineering and consulting excellence. Our highly skilled engineers and consultants benefit from the best training and peer-review/collaboration in the business. Haag’s service areas include forensic engineeringconstruction consultingcertifications, training and productsGIS, BIM, laser scanning servicesproduct & material testing, and fire origin and cause investigations.

An Update to the Enhanced Fujita Scale – March 2022


by Tim Marshall, P.E., Principal Engineer Emertitus, Meteorologist


Dr. Ted (Tetsuya) Fujita created a tornado damage scale in 1970 after the Lubbock, Texas tornado.  The damage scale was divided into six categories where F0 corresponded with minor damage to houses with estimated winds of 40 – 72 mph (18 – 32 m/s) all the way up to F5 where strong frame houses were swept off their foundations in estimated winds of 261 – 318 mph (117 – 142 m/s).  Dr. Fujita determined the failure wind speeds based on dividing the gap between the Beaufort Scale (which mariners use) and the Mach Scale (which aviators use) into 12 non-linear increments.

In the early 2000’s, wind engineering studies showed mounting evidence that wood-framed houses can be completely destroyed at wind speeds less than 261 mph (117 m/s).  Therefore, in 2001, the Wind Science and Engineering Center at Texas Tech University assembled a team of atmospheric scientists and wind engineers and developed the Enhanced Fujita (EF) Scale to address the inconsistencies of the F-Scale.  I was selected along with five other scientists to estimate failure wind speeds to various building types.

In 2007, the National Weather Service (NWS) adopted the EF Scale and began utilizing the recently published EF Scale document to evaluate building damage.  A copy of the EF Scale document can be found online at:  This document includes degrees of damage (DODs) to 28 Damage Indicators (DIs) and was much more complex and accurate than the original F Scale.  However, concerns remained about the relationships between the observed DoDs and wind speed ranges. Some DIs had limited guidance available.   Users of the original EF Scale asked for new DIs to be created, especially in rural areas where building DIs are not common. More recently, alternative methods of estimating wind speeds have been published, including mobile Doppler radar measurements, tree-fall pattern analysis, and failure analysis of engineered structures. None of these methods had been included in the process of estimating tornado wind speeds. As a result, there have been awkward adjustments in tornado intensity by the NWS, including El Reno, OK and Bennington, KS in 2013. Additionally, recent research comparing wind speeds estimated from mobile Doppler radar measurements to speeds estimated from damage using the original EF Scale demonstrated an alarming trend, whereby wind speeds in approximately 40% of tornadoes were underestimated by two EF numbers. This means wind speeds for many tornadoes may be on the order of 50 mph greater than is currently being estimated and recorded in the national tornado database using the 2006 EF Scale (which is the dataset that serves as the basis for all tornado hazard maps).

In 2014, the American Society of Civil Engineers (ASCE)/Structural Engineering Institute (SEI) and the American Meteorological Society (AMS) undertook an effort to develop a consensus standard for tornado wind speed estimation. The forthcoming ASCE/SEI/AMS standard, Wind Speed Estimation in Tornadoes, will officially standardize the EF Scale. The committee undertaking this effort is organized into seven subcommittees, which were established to upgrade the EF Scale and develop methodologies to use treefall patterns, radar measurements, in-situ measurements, remote-sensing data and forensic engineering to estimate wind speeds. Requirements for archival of data will also be included in the standard.  Both myself and Dr. Christine Alfano, P.E./CCM with Haag serve on this committee.

Updates to Version 2 of the EF Scale include developing new DIs, such as center pivot irrigation systems, religious buildings, passenger vehicles, and wind turbines, as well as redefining existing ones using knowledge gained from more than two additional decades of conducting damage evaluations using the original EF Scale. Additional updates included combining single- and double-wide manufactured homes into a single DI, creating separate DIs for wood-frame and concrete residences, recategorizing schools as single- or multi-story, and revamping the hardwood and softwood tree DIs to focus on single or multiple trees instead. Wind resistance levels have also been defined to aid in estimating the wind speed associated with specific visible damage. Where new research exists from laboratory, modeling, or other sources of data, wind speeds for specific damage states are also being updated. Updates also include improvements and standardization of the DoDs and associated wind speeds across DIs, and standardization of a procedure for the use of the EF Scale method. Representative damage photographs to serve as guidance, as well as a commentary with references, have been added to each DI. Many of these damage photographs comes from damage surveys that I conducted.  However, the range of wind speeds that fall within each EF Scale category are not anticipated to change.

More than 80 scientists from various disciplines have volunteered their time to develop this standard. Thousands of hours have been put into this effort, and it is anticipated the standard will be published within the decade. Public input will be requested once the draft standard has completed the committee balloting process.  It is anticipated the new standard will be issued within the next few years.  Stay tuned to this blog for future updates.


By Tim Marshall, P.E., Meteorologist, Haag Principal Engineer

Tim Marshall is a structural engineer and meteorologist.  He has served as a Haag Engineer since 1983, assessing damage to thousands of structures (particularly damage caused by wind and other weather phenomena). He has written numerous articles, presented countless lectures, and appeared on dozens of television programs in order to share his extensive knowledge re: storms and the resultant damage.  He is a primary author of many Haag Education materials, including the Haag Certified Inspector-Wind Damage course. Mr. Marshall a pioneering storm chaser and was editor of Storm Track magazine. See his profile here.

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.