shop drawings

[wildehond]

Does anyone have an opinion on responsibilities for dimensions on shop drawings?

While we do the structural design and provide general layout drawings of structural steel members, we always ask for shop drawings for structural steel buildings from the manufacturer. We then look over the drawings and approve them prior to construction.

By "approving them" do we accept liability for something that then ends up with the wrong dimension on site? Is there some kind of standard disclaimer note that we could use to say that we're in agremeent with the members and connections shown, but not the member lenghts?

 

[gfbotha]

WildDog, in my opinion, if you actually/physically signed off drawings with a wrong length indicated on it, then unfortunately you will have to accept some kind of liability. Checking easily becomes a tedious job, but still.

I can understand that if you could show that your original input (layout drawing with lengths) had the particular length listed correctly, you might feel you have a case..., but it is going to be difficult. It probably depends, who is contracting who, and who is part of who.

I doubt whether a disclaimer should exclude length because, although it hopefully would not fit, the length is directly involved in the structural integrity of a member.

 

[wildehond]

Gfbotha, thanks for your reply. Clearly, length is connected to structure, but when something is 150mm out, the structural analysis may still prove code compliance, while an architectural feature doesn't fit.

 

[COEngineeer]

I do residential and we dont review structural steel shop drawings. The only thing I review is roof trusses shop drawing. I have to make sure it jives with my design. I think contractors are more qualified with reviewing dimensions so I think they should do it.

 

[dik]

My standard transmittal for shop drawings has a note to the effect that review is void unless the drawings have been reviewed by the contractor for several issues. The shop drawings are reviewed and never approved... also work is reviewed, never inspected.

Do you have anything on the documents that states that the contractor is responsible for fit and measure? confirming site dimensions?

Dik

 

[bridgebuster]

I would say it depends on what is in the contracts between you and the client and contractor and client.

My work is with public agencies; they make the contractor responsible for fit-up. When we review shop drawings, our main intent is to ensure that the design intent is carried out. Take a plate girder shop drawing for instance, we check to see that the plate sizes match our drawings, splices are where they should be; number of cross frames , etc; dimensions for fabrication are not checked.

 

[SperlingPE]

The contractor and supplier are still responsible for constructing the building. The review of shop drawings is to generally confirm that the intent of the contract drawings is being meant and in no way relieves the contractor of any responsibility. That being said, I will review the grid to grid dimensions on shop drawings. I will provide rough opening sizes if they are not shown on the contract drawings. I will provide any dimensions that are required to construct the building if the dimensions were not provided on the contract drawings (i.e. distance from a beam line to the face of a cmu bearing wall). For additions to existing buildings, I note that the contractor and supplier shall field verify all dimensions.

 

[gfbotha]

WildDog, yes, unfortunately it is likely to be out only a small bit - I merely wanted to make the point that I don't think one could simply exclude length using a disclaimer.

Actually I also thought it should be the contractor's responsibility and that you should not sign off shop drawings, if possible... Regulation-wise, are your design/layout drawings not enough?

 

[Rentapen]

All dwg's, layouts and details, must be approved by a PE or AIA. Fab shops most time do structural detail and fabrication from contractors, always late with dwg's and loads of revisions, and don't employ AIA's or PE's because of cost. We build what you DESIGN and APPROVE no matter how goofy it is.
just wandering Ohio.
rent

 

[oldrunner]

In regards to the wood trusses, does any of your firms design the permanent bracing as required by the TPI code? The truss manufacturers don't do this.

 

[MWPC]

We use the term "review" rather than "approve". We have an elaborate note on the stamp that tries to limit our responsibility for the review. We want to be sure that the contractor interpreted our design correctly but we do not check that his holes line up. Check with your insurer. Ours provided the weasel wording. Ken

 

[HgTX]

Our drawing review stamps have big disclaimers on them along the lines of the review being for general correctness and we are not liable for any errors, etc.

Hg

Eng-Tips policies: faq731-376

 

[SteveMort]

Our liability insurance provider recommends that a rubber stamp be produced for use on all shop drawings. There are to be five checkboxes marked: Approved, Approved as Corrected, Rejected, Revise and Resubmit, and Submit Specific Item. And the following text:"This review is only for general conformance with the design concept of the project and general compliance with the information given in the Contract Documents. Corrections or comments made on the shop drawings during this review do not relieve contractor from compliance with the requirements of the plans and specifications. Approval of a specific item shall not include approval of an assembly of which the item is a component. Contractor is responsible for: dimensions to be confirmed and correlated at the jobsite; information that pertains solely to the fabrication processes or to the means, methods, techniques, sequences and procedures of construction; coordination of the Work of all trades; and for performing all work in a safe and satisfactory manner." The Company name and a phone number should appear at the bottom with a blank line for a date and the initials of the person reviewing the shop drawing.

 

[HgTX]

It gets to the point where there's no room on the front of the drawing and they have to be stamped on the back. But we can't find the back of the electronic drawings...

Hg


Eng-Tips policies: faq731-376

 

[bjb]

At every firm I have worked at, shop drawings were only reviewed for the design intent. In other words, making sure the beam sizes are correct, that the details match the structural drawings, and that the connectiond are adequate.

Our review does not relieve the contractor from following all of the dimensions in the contract documents.

With that being said, I quickly review what they have for the building grid to look for any obvious errors.

 

[JAE]

You should read [red]AISC's Code of Standard Practice[/red] found here:

http://www.aisc.org

look under ePubs and free Pubs

Here is a relevent paragraph from the Code:

[green]Such approval shall not relieve the Fabricator of the responsibility for either the
accuracy of the detailed dimensions in the Shop and Erection Drawings or the
general fit-up of parts that are to be assembled in the field.[/green]

The Fabricator/Contractor is responsible for the dimensions and fit up of the pieces. The Engineer of Record only checks for general conformance with the design - among other things also listed in the Code of Standard Practice.

 

[wildehond]

Thanks for all these replies. All heartening and useful