Building a Forensic Investigation Plan


The inspection plan that a forensic architect or engineer comes up with after they’ve reviewed everything is a plan on how to move forward after the initial visual inspection. This sometimes includes performing invasive testing to the building envelope (outer structure) and interior components (walls, floors, and ceilings) to allow an expert to see as-built conditions and check the performance of building components over time.

For example, an owner wants to investigate an older building with a window on outside (stucco or wood) wall that is apparently leaking. Maybe the current resident has complained about stains on the interior drywall. However, the original drawings don’t show how that window was installed or flashed to prevent such leaks.

These days how something like window flashing is installed when a new window is installed when a stucco wall is built is usually left up to the contractor installing the window to decide. Remember “means, method, and procedure?” This is an example of that. These are things that normal trade standards say are best left up to the individual contractors to figure out. Industry groups usually recommend that architects exclude this type of service from their contracts. Architects generally use standardized contract templates provided by these industry groups.

Some of the details that a forensic architect will consider when checking our example of the leaking window above include the following:

  • The type of building/flashing paper used
  • How it was attached to the building
  • How the various layers were lapped
  • The sequence of installation of the paper at the top, side, bottom (head, jamb, sill) of the window

Without this information, the forensic consultant generally will not have enough information from a visual inspection only to know the causes of leaks to in turn be able to responsibly recommend a repair scope to the owner.

Therefore, given assumptions in this hypothetical, some level of surgery or intrusive testing is needed. The forensic consultant will typically recommend a plan and in turn retain a contractor to perform the actual “take off and put back” (removal and reinstallation) of the building components associated with such surgery/invasive testing.

An investigation plan in the case of a window referenced above, the plan will involve some level of testing to the building utilizing a nationally recognized standard for building testing developed by the ASTM (American Society for Testing and Materials).

The first thing that could happen is something like a scaffold will be set up near the window in question. To simulate rain, pressurized and regulated water is sprayed all around the exterior window. Next, interior finishes, drywall/sheetrock, are removed and inspected. Now the window is completed removed, down to the frame so that the way the window and flashing were installed in conjunction with the exterior stucco can be observed.

Notes and pictures are taken every step of the way. After testing a couple windows in this manner, the consultant can get a picture of how all the windows were most likely installed, even though they weren’t onsite when the installation occurred or part of the window specification process. This would only work, however if the same contractor and methods were used throughout the building in question. For instance, when renovations or additions are involved, different methods might have been used at different times.

A forensic consultant will usually use the same approach for any type of building component, assembly, or system. Keeping these things in mind, the building owner setting out on a repair or renovation project can see the benefits that a specially trained consultant brings to the table when developing a project scope that meets the long term project goals of the owner.