Pre-Fabricated Panel Drawings Requiring CO Stamp

[FranCStructures]

Just seeing if anyone out there has an opinion on this matter.
This is in reference to residential construction in Colorado. The contractor/owner on this job decided to have pre-fabricated exterior wall panels designed/constructed in Detroit and delivered to Colorado for installation. We provided a shop drawing review stamped cover letter to accompany the package saying that we had no exception taken to the panels if they were constructed in accordance with the permitted structural drawings. Mind you the panel drawings are just that, drawings of individual panels that do not provide connection details for panel corners or top and bottom.

The applicable building department is requesting that we sign and seal each individual sheet as if it is our design. Not to mention the first time I, the engineer, saw the panel package was the 9th of June, and now they are already in transit to the job site. He is comparing the panels being signed to that of a truss package.

Does anyone have experience with this matter?
Thanks,

 

[Ron]

Yes. You did not have responsible charge of the design and you did not review the construction. In my opinion you shouldn't do it.

 

[mk3223]

Since this was the item added by the Contractor & owner, I agree that you can't be responsible as an engineer to sign off the panel design drawings.
I wondered, however, as reviewed the panel shop drawings, didn't you need to update the structural drawings to show where the additional panel is to be located?

 

[Once20036]

The simple answer is that the design was not completed under your direct supervision and it would be unethical for your to sign and seal the design.

I`m curious about other aspect of the project though, to get slightly off track..
-Did you design this as a stick built wall and the contractor substituted these prefab units instead?
-You say, paraphrasing, "no exception if they're built in accordance with the permitted structural drawings..." Did you intend for this to be a delegated design by someone in CO rather than someone in IL? Wouldn't a typical delegated design need to be signed and sealed by the engineer that performed the design?
-Who provides the connection details at the tops and corners?
-You said that you stamped the cover letter. Do you mean a shop drawing stamp and not your engineering seal, correct?

 

[dik]

As Ron says don't do it... tell the contractor that he has to obtain sealed shop drawings for the building inspector. Let it be their problem and not become one for you.

 

[FranCStructures]

Thanks for the responses, fellow engineers.
Since posting the building department has allowed our shop drawing review letter to suffice. Not to play the usual card but this is what happens when the architect/builder are the middle men and engineer is left out of the loop. I was in agreement with all of your main points though. I did not have responsible charge over the design, therefore the drawings are not mine, and I would have continued to refuse to sign them.

Once: - correct, a bit of an inconvenience really seeing that this was a passive house now and I had to eliminate all exterior strapping that I called out due to insulation on the exterior of the sheathing.
- We never intended for there to be panel drawings. I can't answer that last part, i do wonder how this process typically goes.
- I suppose we are hoping that they are standard details with our nailing patterns. The whole argument is that we reserve the right to review and revise in the field due to how unknown the whole situation is.
- Apologies, we have a shop drawing letter currently, which does get stamped. It's not equivalent to stamping a cover and table of contents or anything.

 

[FranCStructures]

dik: that's what I did. Sure hard to keep clients happy and coming back when they pull things like this and expect the engineer to fix it.

 

[dik]

You have to weigh the advice... but, there are numerous engineers on this site with over 40 years of experience, each... Normally information is corrected as the thread progresses.

You have to explain to your client that your expertise is not in preparation of panel shop drawings and that he would be better served in engaging someone that is more knowledgeable and more efficient at preparing this specialty item.

Dik

 

[dhengr]

FranCStructures:
Why shouldn’t these wall panels be designed, detailed, shop drawings and placement drawings provided, etc. and signed/stamped by that supplier’s own engineer, it is their responsibility; with the same intent and logic as we expect from and apply to metal pl. connected truss suppliers? If the contractor and owner want to do it that way, that’s a delegated design and manufacturing situation, just like trusses. If they want to save a couple bucks per panel vs. site built walls, let them assume the responsibility too. Their designs and drawings should also show all the pertinent connection details to meet the bldg. code. They should also show and provide for any lateral loading requirements, as show on your drawings. And, they should damn well coordinate this with the foundation contractor and make their panels fit the foundation, as built, and the first platform level; so you are not having to adjust ever panel dimension at every corner. The coordination of this whole panelizing effort isn’t as easy as it sounds. I’ve seen a few of these turn out to be real abortions, from day one, on the site.