Certification of shop drawings.

[RARWOOD]

I work for a firm which supplies material and labor for projects through out the Midwest. This requires us to prepare shop drawings, which consist of erection drawings and fabrication drawings.

It has become very common for the type of material we supply to see specificatons which require the submital of certified shop drawings. Some specifications will require that all shop drawings be certified and others will only require certification of shop drawings for certain materials and not for other materials like the structural steel.

Regarding the above practice the engineers on our staff have raised a number of questions.The first question that comes up is what is it that we are being asked to provide certification for?

A simple example is on a project where we supplied a panel product. The panel size, strength and fastening requirements were all specified by the EOR. Our shop drawings which were required to be certified consisted of a panel layout sheet & material list.

The registered engineers on our staff, myself included, are familiar with the concept of certifing that a design was prepared by or under the direct supervsion of a register enginner. However we are left wondering what it is that requires certfication; when the shop drawings consist of a structural plan, provided by the EOR, which we have added mark numbers to the material and provided a material list which shows quanity and size of members.

I know the above examples over simpilfy the problem. However we did have one project where we were required to submit a certified design for one detail which consisted of a standard product with known properties selected from a manufacture's catalog.

My general feeling is that some engineers are trying to subsitute our shop drawings for structural drawings to cover elements of the project which they had not designed. We do not have a problem with submitng certified design calculation or certified design drawings. It is the certfcation of shop drawing that we have a problem with.

What do you think?

There are a lot of issues surrounding this question. One example I dealt with was on an assembly where the shape, member size, fastener size and number were specified by the EOR. The only thing not specified was the fastner spacing, which were all governed by code requirements. However the specifications still required us to submit a certified design for the assembly.

The major question raised in this case was that an engineer certifing the assembly design would be required to state that the design was prepared by, himself or under his direct supervision. I felt that the EOR was asking for certification of his own design by another engineer. which would be prohibited under the governing state requirements.

 

[apsix]

Can the scope of the certification be limited?
A couple of thoughts;
- certify the dimensions to be correct
- certify the shop drawings are to EOR, architect etc requirements
- if some design is done, ie. using Code to determine fastener spacing, then that aspect should also be certified.

 

[dicksewerrat]

Send the shop drawings back to the EOR for his approval. then he certs the drawings.

 

[Ron]

RARSWC...it is likely the "Certification" sought is to see that the shop drawings are consistent with the "intent" of the EOR design. That's loosey goosey.

Understanding what you think the intent of the EOR is and then certifying to that are two different things, particularly when you have a lazy EOR as you described who wants you to design a major part as if it were a subsystem.

In general, I would shy away from "Certifications". In my state, such certifications are actually limited by statute (not precluded, just limited). If you sign and seal something, that should be sufficient; however, in our litigious environment, you are often asked to sign/seal and then certify in the hope that it will in some manner lock you in tighter to the liability issues.

 

[JStephen]

My first thought is to turn this question right back to the one requesting certified drawings, and ask them what they want the certification to show? And confirm that you are not certifying design work done by others.

It is quite often necessary to confirm who is responsible for a particular aspect of design. The usual case is that the specifications require design by the contractor, while the drawings show a PE-sealed detail with no room left for design.

In the drawings, always spell out what aspects of design are by others, and let that get reviewed as part of the approval process.

 

[BFPartners]

I am a structural engineer working with a large multi national engineering consulting firm and our thoughts are as follows:

1. Certifications are to ensure that the fabricator has an engineer on staff and is not short cutting the client by having only technologists on staff. Quality control!
2. Another set of "professional" eyes have reviewed the drawings and no "flags" have been raised.
3. Sometimes fabricators have better connection practices with respect to tolerances and dimensioning. It is customary for the fabricator to place some words covering the extent of coverage the fabricator engineering stamp (seal) is pertaining to.
4. The steel fabricator knows there product better than the EOR. The EOR specifies a steel grade and spec but there are ways that the steel fabricator can get around these requirements and thus it is upto the fabricator to supply the end material.
5. Rebar shop drawings do not have to be certified (Stamped) since the engineering drawings usually have the rebar details. The rebar fabricator is certifying (stamping) the connections and any lap changes.
6. If the EOR provides fabrication and engineering drawings, then the fabricator does not have to certify the drawings since the fabricator will not perform any design work.
7. It simply might cost the EOR more money to generate the fabrication drawings than the steel fabricator.
8. It is an easy way to reduce the upfront engineering cost of a project thus obtaining a PO for a job from the client rather than carrying a higher upfront cost for a job that could be delayed due to a high cost or a job that is not built immediately following the design.

The list goes on and on and on...

 

[RARWOOD]

I want to thank everyone for their replies to my thread. All of them contain valuable thoughts. I wanted to reply to let you know I have read them and I am thinking about many of the issues. Hopefully later this week I will have some time to add some additional thoughts.

The two key issues are liability and assuring qualified people are preparing the shop drawings and looking over the EOR's drawings.