BY JOHN C. PISTORINO, PE, SI
The Florida Board of Professional Engineers reviewed a proposal at its December meeting in Tallahassee to establish an additional category of Special Inspectors of Existing Threshold Buildings.
I want to provide the rationale for revising Chapter 61G15-35 Responsibility Rules Of Professional Engineers Providing Threshold Building Inspections.
The present rules have two intents:
■ One is to provide quality control on new threshold buildings that are being constructed. The purpose of this is to prevent the misdeeds and mistakes made during the collapse of the Harbor Cay Condominium, a five-story building, in 1981, wherein 11 workers were killed.
The rule provides for an engineer experienced in design and construction to certify that all structural components of the building’s frame have been constructed in accordance with the permitted plans. Preferably, the most competent engineer to perform this service would be the engineer of record (EOR) since that engineer is most familiar with the building.
This role is identified as a Special Inspector (SI) of a Threshold Building. The engineer is checking and verifying the contractor’s work, not his own.
However, recognizing that the EOR may not be available to perform this task, the EOR must provide an inspection plan as part of the permitted documents. Therefore, another qualified SI may be engaged.
In addition, the critical means and methods of the contractor involving form work and shoring are also scrutinized since that was recognized as a deficiency in the Harbor Cay collapse. The SI may not be proficient in shoring and temporary support of scaffolding, and therefore must ensure the contractor retains a specialty engineer to not only design the shoring but also inspect it before placing loads on it. The design of such shoring and inspection also becomes part of the permitted plans provided to the building official. The SI has many duties that are performed throughout construction of a new threshold building.
■ The second intent was to have an SI (Limited) provide inspections on existing threshold buildings that were undergoing repair. However, the qualifications of the SI (Limited) were restricted to Non-Substantial Structural Damage type of work. Therefore, that individual engineer did not require extensive design experience since the only activity was inspection.
This designation was intended to increase the number of available qualified engineers for such work. It is assumed that the design of the repairs had been performed on structural components that did not have Substantial Structural Damage, and that the inspection of such repairs did not involve extensive design expertise of the SI (Limited).
A new and more challenging critical problem has developed with respect to existing threshold buildings. This has been brought on by the sudden collapse of the Champlain Towers South in Surfside, Fla., that was undergoing a 40-year recertification for structural integrity as required by Miami-Dade County. This tragedy, wherein 98 occupants perished, has demonstrated the complexity of evaluating an older threshold building.
Up to this time, the 40-year recertification program in Miami-Dade County relied on the FBPE rules that require engineers to perform only work they are competent in. The collapse of Champlain Towers demonstrates the more difficult and challenging requirements for an engineer to evaluate the condition of an existing occupied building and decide if it is safe for continued occupancy.
This type of engineering judgement calls for more experience than an SI was ever required to have. The inspecting engineer must be knowledgeable about how a building is designed, including the significance of loading on individual critical structural members. The existing SI rules deal with an approved design, quality control, and observation of the means and methods of a competent licensed contractor building a new threshold building that is not occupied.
Inspecting an occupied threshold building that may have seriously deteriorated structural components requires the inspecting engineer to make judgements as to:
- How seriously is a component damaged (percent of loss of load carrying capacity)
- What loads the component is supporting that it now may not be capable of supporting (overloaded)
- Is the component in a critical load path with respect to supporting the building frame and structure
- Does the component need emergency shoring and support, and can it be repaired without affecting the integrity of the whole building
- Is it safe for individuals to continue to occupy the building, and what temporary measures are required to allow for continued occupancy and for how long a period of time?
As described above, the inspection of an existing threshold building offers more challenges and decisions of judgment than the current SI rules require.
Therefore, the Board anticipates the need for a higher level of minimum requirements to perform such inspections of existing threshold buildings.
If you have comments related to the proposed rule, please email them to Board@fbpe.org.
John C. Pistorino, PE, is a practicing structural and civil engineer with PE license no. 11007, obtained in 1970. He has been president of Pistorino and Alam Consulting Engineers Inc. since 1986. He holds Special Inspector license no. 202.