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September 20, 2021 Dispute Resolver

Working Creatively with Standard of Care Experts to Attack Damage Models

Angela Caffey, Esq., and Jacob Bice, Ph.D., P.E.


Standard of care experts typically retained to provide expert opinions related to a design professional’s work on a project, if narrowly applied in defending a claim, may be limited to opinions only of a technical nature regarding the original work of a design professional.  However, experienced standard of care experts typically possess additional expertise related to how forensic investigations should be performed, and how data sets are interpreted.  These characteristics can enable experts to represent and contextualize the facts of a given case in a manner that creates opportunities for counsel to reframe the discussion of damages in a substantive manner.

Claimant’s Expert’s Standard of Care In Performing Investigations

By evaluating the forensic investigations performed, and methodically applying the applicable industry standard, defense counsel can expose weaknesses in the claimant’s expert’s conclusions that serve the basis for an alleged damage model. Through this approach, defense counsel can use an engineer or architect to attack alleged damages in an atypical fashion.  While many standards and scientific methodologies may be applied to evaluate the performance of the claimant’s expert’s standard of care, the following two examples illustrate the application of this approach to damages.

Standardized Methods for Forensic Investigations

The American Society of Testing and Materials (“ASTM”) provides a series of standards that present the scientific methodologies employed in forensic investigations. One such standard, ASTM E2128 “Standard Guide for Evaluating Water Leakage of Building Walls,” is the applicable industry standard for performing water leakage investigations and has been recognized by other industry organizations such as AAMA as “the foundation for field investigations of water leakage in building walls.” The standard outlines a purposeful and orderly step-by-step methodology to systematically accumulate information. The seven steps can be summarized in four main categories:

1.       Review of project documentation, including maintenance and remediation records;

2.       Inspection and investigative testing;

3.       Analysis; and

4.      Report.

The first step outlined in ASTM E2128, review of original construction project documentation, is often not the first step claimant’s experts perform. Rather, claimant’s experts tend to jump right into inspection and investigative testing. However, this first step is fundamental to the investigation and “can be classified as the initial homework to be completed before the investigators set foot on the property.” According to ASTM E2128, implementing testing before document review may lead to incorrect conclusion and significantly limit the potential benefits of the test.

When properly executed, the testing phase is comprised of much more than simply performing visual observations of openings into the building’s walls. ASTM E2128 dictates that this phase should be an inspection process that results in a clear understanding of the relationship between all the parts of a wall system that documents patterns of distress and non-distress components and provides a clear understanding of the water infiltration path(s).

During the analysis phase, reduction and interpretation of project documentation and field acquired data is conducted, and patterns and correlations are investigated. The goal of this phase is for the investigator to analyze all the data acquired, as a whole, to have a clear understanding of the complete building envelope. Further, ASTM E2128 indicates that “a graphical analysis is useful for correlation studies. Leak occurrences can be superimposed on building drawings to help reveal patterns that might be traceable to potential leak sources.”

The reporting phase must address the cardinal principle of ASTM E2128 - that all parties have equal access to the data record that is sufficiently documented so that any interested party can duplicate the evaluation process used by any other party.

Case Study #1

Claimant’s expert recommended a complete removal and replacement of all stucco and stone veneer on a condominium complex with 26 buildings that are two- to three-stories high with a total of 141 residential units. After four years of investigation and after issuing three forensic investigation reports, claimant’s expert testified he did not perform the activities prescribed by the ASTM standard, but rather followed his own protocol that is not published or considered an industry recognized standard.  The expert further testified that he did not adhere to several key steps of the ASTM, including mapping patterns of distress and thoroughly documenting his analysis.

Based on this testimony, defense counsel for six different parties jointly retained a forensic engineering firm as a defense expert witness that opined claimant’s expert’s investigation failed to meet the objectives of ASTM E2128 and did not meet the industry standard of professional practice for reporting opinions of technical experts in the building science and engineering field conducting water leakage investigations in-wall.

To substantiate this opinion, the defense expert also assisted defense counsel in graphically illustrating the claimant’s expert’s investigation and conclusions (since that expert had failed to do so). The illustrations transposed the exploratory openings, the reported damage from claimant’s expert, and the existing water intrusion work orders onto the condominium complex. Once graphed, it was readily apparent that out of 21 openings at the window heads, only 7 were not around existing, known leaks and all 7 had no documented damage. After the defense expert graphed every type of opening and reported damage, it was clear that 8 of the buildings had no damage observed by the claimant’s expert. When deposed, the HOA president was visibly shocked at this finding because the claimant’s expert had made it seem as if every building was damaged by the way he reported his insufficient investigation.

Without the context of the graphics developed by the standard of care expert, it would have been difficult to discern a methodology to the claimant’s expert’s investigation since prior to that point the investigation had only been described by lists of locations and photos.  However, once the various components of the investigation were sorted and illustrated, the absence of a methodology to the investigation and the lack of supporting evidence for the claimant’s expert’s conclusions and repair recommendations was evident.

Statistical Analyses of Existing Conditions to Define Extents of Damage

 In addition to industry standards that define test and evaluation methodologies, an expert can also effectively utilize statistical analysis of a given data set and correlate that data with distress in a building to characterize the larger overall performance of a facility.  It is not uncommon for claimant’s experts to extrapolate a damage model to other similar building construction based on localized distress that does not account for initial imperfections in construction.  Statistical analysis provides a scientific methodology for understanding global performance and can refute damage models that may overreach.

A common instance of erroneous extrapolations occurs during evaluations of building movements in slab-on-grade construction.  In these situations, slabs constructed on soils with expansive properties can move, and damage may occur when those movements are of a magnitude greater than those anticipated in the original design.  Typically, these movements are measured by performing a relative elevation survey.  However, this measurement provides only a limited understanding of the movement that has occurred since it captures both post-construction movement and the initial out-of-levelness in the slab immediately after placement.

Further, these measurements alone do not distinguish between movements that are reasonable and should be expected versus those that are excessive and unacceptable.  It follows that understanding the amount of excessive movement that has occurred post-construction while neglecting the initial out-of-levelness and discounting the normal and expected amount of movement is fundamental to developing an accurate picture of the damages that exist.

Unfortunately, it is also not uncommon for initial measurements of the slab elevations to not have been performed by the contractor at the time of construction.  As a result, damage models often do not attempt to distinguish between initial out-of-levelness, normal and expected movements, and movements that could be considered excessive.  Industry standards for construction tolerances, such as American Concrete Institute (ACI) ACI 117 “Specification for Tolerances for Concrete Construction and Materials give insight to what are reasonable limits for initial out-of-levelness, but do not provide insight into the quality of the construction that may be needed when both contractor and designer are engaged in a dispute with the claimant. 

Case Study #2

Claimant’s expert recommended removal and replacement of 100% of slabs on grade constructed on the interior of 14 separate retail buildings after “excessive movements that required remediation” were reported in 7 of the 14 units.  Claimant’s expert stated that initial out-of-levelness of the slabs could not be discounted from the areas requiring repairs since no finished floor elevation survey for the slabs was performed at the time of construction.

A forensic engineering firm was retained to review the conditions at the existing buildings and provide opinions related to the reasonable and necessary extent of repairs.  Relative elevation surveys were performed, and included buildings that exhibited distress from building movements as well as those without evidence of distress. Since most building slabs did not exhibit appreciable damage, but were also not completely level, it was possible to calculate the probable initial out-of-levelness for the slabs.  The defense expert performed a statistical analysis of the relative elevations of the slabs-on-grade not exhibiting damage that would require repairs and found that the elevation data set conformed to a normal distribution.  When this data set was normalized to the lowest measured point in each, the upper quartile of elevations measured exceeded an absolute relative elevation differential of 1.5 inches.  In other words, 75% of the slab elevations were within 1.5 inches of total out of levelness, which corresponds to the allowable initial out-of-levelness tolerance for a slab-on-grade.

This analysis was informative when understanding the total of out-of-levelness that should be considered as excessive.  The construction tolerance for slab-on-grades (+/- 0.75 inches) indicates that one should expect up to 1.5 inches of total out-of-levelness due to construction.  The statistical analysis validated this limit and indicated that it was probable that the original slab construction conformed to the construction tolerances, and therefore established the construction tolerance as a rational threshold of initial out-of-levelness for the project.

In addition, since slabs are sensitive to soil movements, the standard practice is to anticipate a certain amount of normal and expected movement, depending on the type of slab construction and the soil preparation performed.  In this instance, the original geotechnical engineer specified one inch of expected movement in the design report.

Understanding these two values for initial out-of-levelness and the amount of normal and expected movement, a threshold for “excessive” movements could be rationally established as 2.5 inches for this project.  The defense expert digitized the elevation survey results and calculated the areas of slabs that exceeded this threshold to establish percentage of the slab area that could be considered damaged.

To communicate the difference in the two amounts of damage contemplated, the defense expert tabulated the total out-of-levelness of the slab, and then compared that against the percentage of slab area exceeding the 2.5-inch threshold in each building.  The result was that only 3 buildings exceeded the 2.5-inch threshold and, therefore, could be characterized as having excessive movements: Building A by 29.4%, Building D by 9.2%, and Building O by .5%.  To illustrate this concept, the defense expert prepared another illustration to show the specific areas exceeding what could be deemed to be reasonable and expected, and to graphically show and opine on the appropriate extent of repairs. The visual representation of the excessive movements made the discrepancy between the claimant’s alleged damages and the actual damages evident.


Though standard of care experts are typically confined to opining on the performance of other design experts, their experience both in design practice and as a forensic investigator can be leveraged to evaluate and reframe the context for damages being presented by a claimant.  Interpreting and presenting the findings of these experts’ work graphically may illuminate opportunities to expose weaknesses in the underlying assumptions that underpin a claimant’s damage model, and substantiate alternative damage models that are realistic, rational, and defensible.

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Angela Caffey, Esq.

Thompson Coe, Dallas, TX

Jacob Bice, Ph.D., P.E.

Walter P Moore, Dallas, TX | Division 3