Investigation of construction defects requires a multi-disciplinary approach, involving architects, engineers, industrial hygienists, building scientists, and materials scientists. An assignment typically starts with a complaint, sometimes the problem is evident (the paint is peeling, the stucco is cracking, windows are fogging), other times it is apparent that something is wrong but the cause cannot be readily seen (something smells bad, humidity is high, surfaces are water damaged, mold is growing).
Our first step is to gather as much information as possible. This information gathering includes preliminary observation of the problem, and interviews with everyone at the facility that has been involved with the problem. Drawings, specifications, shop drawings, change orders, field notes, lab reports, and product data are all retrieved from the files.
Once on site, the affected areas are inspected to determine the severity and extent of the problem, and to see if there are any patterns that will be indicative of a cause. Non-invasive testing, such as moisture measurements or viewing with an infrared camera, are often helpful at this phase of the investigation. Invasive testing, such as disassembly or destructive testing, can also be required to determine the cause of the observed problem. For example, destructive testing, such as adhesion testing of paint, may be needed to evaluate a paint failure, or disassembly samples may need to be collected to examine the interface between the paint in more detail in a laboratory, or for chemical analysis. Areas to be tested or disassembled are determined on a random sample basis. If a truly random selection is not possible due to occupancy considerations, then care must be taken to be sure that there is no bias in the areas selected.
When disassembly is needed, it must be performed with great care to avoid disrupting or hiding the conditions
that may be causing a problem. This may require the use of non-traditional tools such as scalpels and field microscopes to carefully expose the details of construction, and use of precision measuring instruments. Frequently, it is useful to have construction workers available for larger scale removals, and to handle ladders and lifts. Once the problem is found it is documented as needed with field notes, drawings, photographs and videos. For problems that are widespread over many parts of a facility it may be necessary to disassemble multiple locations to determine if all defects have the same cause. In this instance, the number of required inspections, and inspection locations are determined statistically in order to avoid bias.
Where there is a material failure, material data sheets, MSDS sheets, installation instructions and details are secured from the manufacturer. Frequently, the technical representative for the manufacturer will be interviewed.
Usually, this investigation is sufficient to determine the cause of the failure, and also determine what is necessary to correct the problem and repair the resulting damage.
On very complex situations, or where the stakes are very high, we may collaborate with other specialists. For example, when investigating corrosion on columns in the World Trade Center Towers we collaborated with the Corrosion Laboratory at the Rensselaer Polytechnic Institute Materials Department. In the past we have collaborated with subject experts on topics such as adhesive chemistry, and deterioration processes such as corrosion, changes in chemical composition or polymerization of materials, materials testing, laboratory analysis, toxicology, epidemiology, disaster response, and statistical analysis. When working with subject experts we put together the needed team and lead the collaboration. Often, the reports from subject experts will be too technically complex to be understood by the technical laypersons such as facility managers, who ultimately need to make informed decisions. For this reason we will generally issue a summary report, which is reviewed and approved by the subject experts, and than include the original technical reports as attachments.
When a dispute arises between the facility owner, and the party or parties responsible for the defect, we use educational tools such as drawings, videos, computer animation, models, and samples to explain our findings, which often include complex technical issues, in a form that is technically accurate, but which can be understood by the laypersons involved.
Here are some examples of past projects that illustrate our approach.
- Evaluation of Mold Amplification and Moisture Dynamics in University Dormitory
- Water Intrusion in Community Library Building
- IAQ Air Sampling Identifies a Construction Defect
- NYC Low Income Housing Development Removal Cost Litigation
- Odor Investigation