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Incorporating Technology into Forensic Investigations

DonanEngineering Articles, Commercial & Residential Roofing, Forensic Engineer, Forensic Engineering, Geotechnical, Drought & Earth Movement, Hail and Wind, Water Losses

Whether it is helping us formulate our opinion or confirming an initial diagnosis, technology plays a valuable role in forensic engineering work.  Following are a few examples of existing technology available to Donan’s project managers. Though not standard issue, these tools are utilized when necessary to accurately determine or confirm a cause of loss.

image 1Many blemishes occur on shingles that are not consistent with hail impact but detailing an exact cause can sometimes be speculative.  Thermal bridging from underlying nails leads to such blemishes and it can easily be verified if the shingles are unsealed.  However, if the shingles are well sealed, this conclusion can still be confirmed with the use of a steel locator.  The following photo shows the use of a steel locator to confirm the presence of an underlying nail on a circular blemish.  On this project, this type of blemish was the primary cause of distress to the shingles and the use of the steel locator confirmed the project manager’s opinion without causing damage to the shingles or leaving room for doubt. 

 

IMAGE 3An anemometer is used to measure the flow rate of air.  In the field, an anemometer can be useful when attempting to diagnose the cause of elevated moisture or fungal growth that develops in the absence of a leak or other direct sources of moisture.  In these cases, it is possible that relative humidity is elevated due to inadequate air exchanges within a problem area versus other areas of the property.  The anemometer can be utilized to verify flow rate from registers for forced air ventilation systems.  While other factors must also be considered, the use of an anemometer in conjunction with a thorough inspection, including other tools, can help establish or reinforce a basis for inadequate air flow as the cause of elevated moisture conditions.

 

IMAGE 4If your project involves movement of building materials, the use of a ZIPLEVEL® might be what you need to help formulate your opinion or reduce your time spent on site gathering information.  Currently, the ZIPLEVEL® is being utilized by project managers to take relative floor elevation surveys for uniform floor systems (i.e. concrete slab-on-grade and wood floor framing).  These surveys help determine difference in elevation from a selected reference point.  After this data is gathered, contour maps are developed as shown below.

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These maps are then analyzed, and conclusions regarding relative movement of the system and direction of movement can be confirmed.  This information substantiates common conclusions regarding movement resulting from differential settlement and heave; however, this tool could be used for any other applications to analyze relative movement of horizontal surfaces.

image 6Infrared thermography measures and images infrared radiation emitted from an object.  The infrared camera is able to calculate and display temperature, as radiation is a function of the object’s surface temperature.  Temperature differences are identified by changes in color.  The FLIR ONE™ camera is a tool currently used by project managers to locate or confirm sources for water intrusion and openings in building materials that are not accessible for inspection.  The camera is used alone or in conjunction with other tools.  The following photographs are from projects looking to determine the cause of damage.  The photograph on the left is viewing water damage to the ceiling in an area beneath a bathimage 7tub.  A FLIR camera was used in conjunction with a moisture meter, visual inspection, and hot water testing of areas to determine the exact location of the water leak.  The photograph on the right is viewing water damage to areas along the base of a bathroom wall.  A FLIR camera was used to demonstrate the location of surfaces where condensation of humidity could result from surface temperatures being colder than the dew point and substantiate the opinion as to causation of moisture damage.