Why things fall apart: Lessons learned

While inherent materials issues are rare, they do occur, and the associated failure can be dramatic—such as this example of spontaneous glass breakage due to nickel sulfide inclusions. Enhanced quality control during fabrication has helped limit such failures. Photos courtesy Wiss, Janney, Elstner Associates Inc.

Looking back over the many Failures columns published in The Construction Specifier provides an interesting exercise in understanding how and why construction materials and systems fail.

A review of these columns reveals several recurring themes as to why things fall apart:

Inherent deficiencies in construction materials, while uncommon, can lead to systemic failures.

Workmanship problems, such as repointing or resealing joints in masonry without proper preparation, are more common and can lead to widespread failures.

Use materials that are incompatible with one another, or with an existing substrate, can also lead to failure.

Issues with interface detailing which is dependent not only on the design but also on sequence of construction and coordination of the trades involved, can lead to problems with the building enclosure.

This 1920s brick masonry façade illustrates several Failures themes, including inherent deficiencies (brick that was not well mixed or fired); workmanship problems (repointing without proper joint preparation); use of incompatible materials (overly hard mortar); and inappropriate past repairs (the brick was previously damaged by abrasive blasting).

Errors during original construction can occur with new or older construction.

Lack of understanding of existing problems, such as recurring water leakage, can lead to significant deterioration over time.

Inappropriate past repairs can result in failure of the repairs as well as deterioration of adjacent materials.

Environmental exposure causes aging of materials, but more immediate failure can result where exposure is not considered in selection of materials and systems.

Past Failures columns also illustrate what approaches can be followed to avoid failures and, where needed, implement repairs:

Look for compatibility issues and consider where and how materials and systems interact—whether they can be used in combination or if adjacent, must be separated. Determine what special detailing, sequencing, and coordination are needed for interfaces.

Consider the environmental exposure, long-term serviceability, and maintenance requirements of the materials and systems being specified.

Ensure specifications include requirements for physical samples, trials, and mock-ups to allow the design team, owner, and contractor to understand the process for construction and repair, as well as the result. Where appropriate, specifications should include testing of mock-ups to evaluate performance.

When unusual or unforeseen field conditions require modification to details during construction, consider all aspects of performance, including structural integrity, air and water infiltration, thermal performance, durability, and serviceability.

Where needed, perform regular inspections and monitor conditions of concern to identify problems requiring attention before deterioration becomes severe.

When repairs are needed, permanent rather than temporary repairs are preferred. All repairs should be designed with a clear understanding of the issues involved and implemented by skilled tradespeople.

Understanding past failures provides guidance on how to avoid failures in the future. These common themes in why materials and systems fail, and how failures can be avoided, also demonstrate that preventing failures is a responsibility shared by the designer of new construction or repairs, the owner, and the contractor implementing the work

Kenneth M. Itle, AIA, architect, and associate principal with WJE’s Northbrook, Illinois, office, contributed to this column.

The opinions expressed in Failures are based on the authors’ experiences and do not necessarily reflect that of The Construction Specifier
or CSI.

Deborah Slaton is an architectural conservator and principal with Wiss, Janney, Elstner Associates (WJE) in Northbrook, Illinois, specializing in historic preservation and materials conservation. She can be reached at dslaton@wje.com.

David S. Patterson, AIA, is an architect and senior principal with WJE’s office in Princeton, New Jersey. He specializes in investigation and repair of the building envelope. He can be reached at dpatterson@wje.com.

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