Rick asks: What level of shop drawing preparation needs a professional engineer?
NPCA technical experts answer:
Engineering practice is defined in different but similar ways by governing authorities. In general, an engineering work involves performing a service, conducting analysis or creating a design for a public or private entity in connection with a utility or structure. If the process of preparing shop drawings from an approved standard detail includes making any judgment calls about structural elements of the product such as required strength, material properties or structural design, then the shop drawing is instead an engineering work and should be considered as such.
However, if the shop drawing is merely a depiction of an approved standard detail that contains all of the necessary design information, such as maximum placement depth, design live loading, minimum concrete strength, minimum steel size, strength and placement, then the process of transferring those parameters onto a separate drawing that is easier for the plant to use to manufacture the product and easier for the project owner to review for compliance to the standard, arguably does not cause the shop drawing to be an engineering work and it should not require an engineer’s seal.
One caveat to this is that the project owner is still within their rights to require a seal on the shop drawing for their assurance, even though the process of converting the depiction of the engineering design to a different format does not inherently change the engineering design.
Getting more technical, the National Society of Professional Engineers’ Rules of Practice restrict engineers from sealing any designs “not prepared under their direction and control.” This would preclude engineers from sealing work that has already been performed by another in creating an approved design standard. A public or private entity should not use the color of their authority to require someone else take responsibility for a design they require on their project. However, some entities may assert that, although the signing engineer did not select the design, nor was the design prepared under their direction or control, they are at least responsible for the implementation of the design and therefore must place their own seal on the shop drawing.
Ultimately, the engineer needs to follow the law and ethical standards while working to meet the needs of the project owner. It is important to have a good relationship to have transparent discussions and derive the right solution for each project. The engineer should make it explicitly clear what engineering work he or she is performing.