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Contractor requesting calcs
4

Contractor requesting calcs

Contractor requesting calcs

(OP)
We worked on renovations to an existing auditorium and our work included structural calcs to determine the capacity of the existing floor for some added loading. The contractor needs to bring in a tall/heavy cherry-picker to renovate some art work on the ceiling of this building. He has requested our calcs. I assume he wants to get an idea of the floor capacity.
Personally I wouldn’t mind giving him the calcs because a) he could make the same request to the owner and the request would trickle down to us anyways b) I think it would help the contractor expedite his work.
So I think we should be OK giving him the calcs with a clear disclaimer that his question relates to mean and methods and any conclusions his structural engineer draws from these calcs are at their own risk.
Have you ever received a request like this and if so, how did you handle it?
Thanks.

RE: Contractor requesting calcs

Sometimes on bridge projects contractors ask for calcs, for the same reason, equipment placement. The request always comes through the owner. We don't take issue with it. Clients typically request that we review the contractor's work.

RE: Contractor requesting calcs

If the owner wants to give the calculations to the contractor, that's up to them. My clients very seldom show any interest in calculations.
But if the contractor wants to exceed the design loads, they need to hire their own engineer and evaluate the design. I'd say the more distance you place between that decision and your company, the better.

RE: Contractor requesting calcs

Your disclaimer is fine - especially reference that the contractor should hire a structural engineer do their OWN calculations and only use yours for reference.

This is done all the time and it is not wrong for you to recommend/assume that any special construction related loads be dealt with by another "construction" engineer as these sometimes can be
highly specialized - i.e. related to the equipment loads.

As EOR of the project, it might even be proper for you to insist on another SE to review it.

RE: Contractor requesting calcs

JAE... for liability reasons, the contractor should use his own SE...

Dik

RE: Contractor requesting calcs

dik - I agree. I thought that is what I said but maybe I fuzzed it up a bit with too many words.

They should insist that the check of the structure should be the contractor's (and their SE's) responsibility.

RE: Contractor requesting calcs

Why shy away from it? As the EOR WWTeng has a better understanding of the structure than a another engineer brought in later to review specific types of loading. Assuming of course the Contractor will pay we never shy away from this type of work. If something goes wrong you are getting drug in one way or the other since so might as well be proactive IMO.

RE: Contractor requesting calcs

dcarr - we shy away from it because we are careful not to be in a position, on the same project, where we are working for two different "masters".

It can create a condition where there is a real or percieved conflict of interest.

RE: Contractor requesting calcs

WWTEng:
I agree with Dcarr. At the moment, there isn’t anyone who knows that structure better than you do, given the work you have already done, and there is no one better than you to do this additional study and engineering. And, that’s what you should be selling, rather than giving away your previous work which was done for a somewhat different, but not unrelated reason. Obviously, you shouldn’t do this for no compensation, with no additional investigation and study if needed, and you shouldn’t have more liability foisted on you without the appropriate involvement and input. But, you can be sure you will get dragged into the fight if something does go wrong, so you might just as well have some control over it, and put your existing knowledge to good use. This should also be less costly to the contractor and take less time too. It is a funny thing the way we do business these days, by slicing and dicing this kind of work, so no one knows what the other is doing, everyone has to fart around redoing what others have done already, responsibility and detail gets lost in the shuffle, etc. Of course, the attorneys love the additional deep pockets and the confusion, that just add to complex and very expensive resolution of any problems.

RE: Contractor requesting calcs

I wouldn't do the work directly for the contractor. If you're inclined to do the work, I would have the contractor contact the owner (they're already working for them) and work out your payment between those two. Then evaluate the design for the owner and have them pass the information to the contractor.
That way there's no conflict.

RE: Contractor requesting calcs

I know some firms destroy their calculations once a permit is issued. Drawings are approved not the calculations. I would not suggest providing any calcs to a contractor. If something does go wrong you could find yourself in a suit, regardless of the disclaimer note.

I don't even like providing them to the owner, review the contract and what is required. This may sound not very customer friendly, but with the amount of attorney's in the United States I would error on the safe side.

Have a verbal discussion with the contractor, explain to him your understood design loads and capacity, but I would document or send anything in writing unless contracted to do so.


RE: Contractor requesting calcs

I would give them to the contractor, with the disclaimer. We as engineers need to stand behind our work, and not be afraid of providing a calculation. If you know your providing a calc, you may check more things that normally you might let slide without checking.

RE: Contractor requesting calcs

(OP)
I am with JAE on this one. We don't want to be working for the owner and the contractor at the same time, especially when the contractor's work involves mean and methods. Plus we are currently simply too busy to take on new work from a new client.

RE: Contractor requesting calcs

(OP)
TDIengineer, we actually already supplied our calcs for the city to review. It is required in this jurisdiction.

RE: Contractor requesting calcs

I have always done exactly what JedClampett recommended.  Do the work for the owner, and if that is not accepted, don't get involved.

As to destroying calculations like TDIengineer suggested some firms do, I think that is negligent.

RE: Contractor requesting calcs

Calculations are always (usually) required for the building official to review, but the plans are approved not the calculations is my understanding.
Drawings are approved not the calculations so destroying the calculations is not negligent in my opinion. The design can always be justified again by calc if necessary. If you get into a lawsuit, the calculations just become ammunition for the forensic attorney's engineer, this has been my experience. Why else would a large firm destroy their calcs? Pure liability reasons... If you think it's negligent, blame the countless attorneys. Just my opinion!



RE: Contractor requesting calcs

Many public agencies require the EOR to submit calcs as part of the review and permit process and I'm pretty sure the final calcs then become public record. Since the agency has the calcs, destroying the originals is not only dumb, it's also pointless. In addition, every engineer I know worth his salt keeps copies of such calcs for his personal archive.

BTW, in a professional liability action, you are sure to lose if you can't document your design with calcs, which should be stamped and signed. The other party's attorney is going to have a field day.

==========
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

RE: Contractor requesting calcs

Think of it this way. A failure occurs. You are on the stand, defending your design. The attorney for the other side asks you why the calculations were destroyed. What do you say? No matter how you answer, truthfully or not, a perceptive juror will assume you shredded the calculations to cover up your mistake. Case closed.

This is the first I have heard of systematic destroying of calculations. Throwing them away or losing them after years have passed, yes, but destroying them willfully once a permit is issued, stupid.

RE: Contractor requesting calcs

I feel the same way as many here regarding having a contractor as the main client. I have had bad experiences and I think is a bad setup. The building owner is my preferred party to report to. As to the idea of destroying calculations after permit is issued I find unacceptable.

RE: Contractor requesting calcs

An attorney advising a former firm advised us (civils) to destroy all files as soon as possible. His reasoning was that the files could only harm you in court. Absence of files may imply negligence, but an error in the files proves it. He wanted the final constructed product to stand or fail on its own merits and to make the opposing lawyer show that a physical failure was the result of a design error outside of ordinary care, without giving the opposing lawyer access to the design files.

RE: Contractor requesting calcs

That attorney may know how the legal system works at times, but his advice is unethical. Not surprising.

RE: Contractor requesting calcs

For those in disagreement, its fine by me. But referring to worth a grain of salt etc.. is just uncalled for.

I find your lack of respect for lawyers and the law naive. It's all about controlling information, think NSA. Attorney's don't play fair, they try and make money. Unlike engineer's lawyers are good at that part.

If only engineers existed in this world, keep all your calcs.. Frame them in fact. But in this country that is litigation happy you don't even have to have done anything wrong necessarily to get dragged into a law suit. And if a large firm has a junior engineer prepare some calcs that aren't properly checked and you combine that with contractor error, you could be in for trouble.

The contractor will do his best to drag the engineer's and architects down with them. Using the calculations to justify as such is a usual path is what I have read and seen.

But again, we are all entitled to our own opinion. That's the beautiful thing about this country!

Regards.

RE: Contractor requesting calcs

Would be interesting to hear what Ron has to say about destroying calculations. He probably has more experience with the US legal system than anyone else here.

RE: Contractor requesting calcs

I don't see why who is paying the bill makes a difference. You engineering opinion shouldn't be changing based on who pays the bill. The structure can handle the equipment or not. I see no conflict of interest working for both the owner and contractor so long as the owner is ok with it.

RE: Contractor requesting calcs

There's no conflict unless a conflict arises.

Taking fees for engineering services from two different entities (who might someday get in a lawsuit/conflict) on the same project could put you between two squabbling firms.

I would agree that if the owner/client agrees with you providing those services for a fee then perhaps its just an accounting/bookkeeping issue as to where the money flows.
But there's always an issue of the sense of client trust that gets warped when you split "alliances".

We just try to avoid it as much as possible.

RE: Contractor requesting calcs

We get asked questions like this a lot on projects. If I have time in my schedule then I will answer these means and methods questions for the contractor (to be a team player), but I would not provide calculations to a contractor who is not our client for a service which we're not being paid.

RE: Contractor requesting calcs

I did forget about the calculation part. I probably wouldn't give them the actual calcs for the purposes of their equipment loading. I would provide framing information to a 3rd party engineer, but probably not my capacity calculations as a basis for their work.

RE: Contractor requesting calcs

Another consideration: Technical calculations are a specialized tool of the trade. Things that we assume are clear are easily misinterpreted by even skillful contractors.

I would try to avoid this conversation:

Contractor: "You have a 100 psf load permitted for this 200 sqft slab. Therefore, I can put my 20000 lb outrigger load in the middle of the slab without problems."
Engineer: "Let me take 5 hours to explain why this is a bad idea and why you don't understand my calculations."

I don't mind providing calcs for reviewers to verify my assumptions, I don't like giving calcs to contractors so that they can derive their own engineering conclusions from.

And as for destroying calcs: that seems foolish. They are a valuable resource long after shit has hit the fan. Rather than systematically destroying evidence, take that time to ensure your calculations are accurate and your assumptions are valid. Preemptively shredding your design aids is like placing bad reinforcing steel then 'accidently' pouring concrete so the engineer can't find your mistakes. Foolish.

RE: Contractor requesting calcs

Shredding calculations is a really bad idea. It’s even bad legal advice. A typical insurance policy will cover errors and omissions claims but will not cover negligence. “Negligence” is defined as not performing up to the standard that would be expected of a typical engineer under similar circumstances. An engineer’s calculations not being 100% correct: that does not constitute negligence. No one is going to pour over every page of your calculations and say “Haha! You forgot to factor in this 1.1 coefficient. Negligence!” What is more likely to happen in the event of a lawsuit is that a 3rd party structural engineer will be brought in to analyze and “reverse-engineer” the structure shown on the design documents. Someone coming in after the fact may be able to analyze the structure with calculations, but they won’t know your design as well as you. If you are a competent engineer, there was probably a good reason for designing something the way you did, and the calculations can prove this. If you don’t have the calculations, you are at the mercy of the expert witness.

As far as getting rid of them as soon as the permit is issued, before the building is even constructed, well that’s just bad practice. I constantly refer back to my calculations during construction when RFI’s start coming in. What do you do when the contractor asks if they can change something for a field-fix or an alternate detail or the architect needs to cut a hole you weren’t anticipating, re-calculate everything in that detail over again? It’s good to know what you were thinking during design, because by the time it gets built, you may not remember.

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