Use of SE stamp

[PostFrameSE]

I have been asked to stamp an agri-business structure with my SE stamp for loads less than the ASCE 7 prescribes. This structure is actually going in an area of the US that does NOT require buildings to follow any code or design standard. So for argument sake, is it wrong, or dangerous to use an SE stamp to give a building owner the confidence that a structural engineer has designed the building for a windspeed of 75mph when all engineers know good and well that the ASCE 7-05 has minimum windspeeds of 90mph? This is what the owner has asked for because he doesn't want to pay for what it would take to design it to a 90-mph wind speed.

Put another way, is it my "right" as a design professional to use my stamp to "certify" whatever I want so long as I state the criteria by which I'm stamping it, or does the mere fact that I obtained the stamp bind me to follow generally accepted documents like ASCE 7 regardless of whether there is an AHJ stating that there is a code or standard to follow?

Thanks

 

[JAE]

Canuck67 - exactly.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[dcarr82775]

I don't see stamping calcs for the building as all that different than the drawings. The drawings are presumably based on the calcs so you are on the hook. I wouldn't stamp something that I know doesn't meet Code minimums regardless of whether or not there is an adopted Code.

Ask you state board for their opinion. Will take a bit longer to get a response of course

 

[jayrod12]

I don't see how stamping calculations is the same as stamping the drawings.

If someone came to me and asked to design a stud wall for a 75 MPH wind speed and 20 feet of roof load at 36psf and 15 psf for snow and dead respectively I can do that. It's a design check, it's not accepting liability for the wall that is built in a specific location. It is accepting liability that your calculations for a stud wall subjected to that specific design loading proves it is adequate.

I'm sure if you tried hard enough on any timber framed building you could find enough deviations in construction from the design drawings to render yourself non-liable.

Maybe we're too nice up here in the north. Although we also aren't litigation happy like everyone south of the border.

 

[Ron]

JAE and Canuck67.....exactly!! The standard of care typically includes meeting the minimum design standards. Deviating from a code requirement with justification might not get you into trouble, assuming engineering judgment is employed and documented. Deviating from the standard of care gets you into deep poop!

 

[TLHS]

jayrod,

I wouldn't be stamping a design I'd done for an arbitrary design condition unless the design spec I was passed was stamped by someone taking responsibility for it, or I had some sort of contractual assurance that what I was doing would be only used as a detail to be applied by a knowledgeable engineer. If I didn't have that, I'd be doing my own sanity check on any design conditions I'm given. We're not supposed to be calculation monkeys, we're supposed to exercise our judgement to ensure the safety of the public.

 

[jayrod12]

Everyone's points are correct.

I don't see providing calculations the same as providing sealed plans in certain cases.

A good point is manufacturing equipment supports. I'm not designing to code level values, I'm designing to client dictated values for equipment.

I'm likely off-base, and if it were me in Postframe's position my mentality might be different. However,I see the owner wanting some assurance that his building has been designed to 75MPH regardless of what the code level values are. How else, besides an engineer providing calculations, is he supposed to have that assurance.

So many of you are scared by litigation that you aren't willing to look outside the box.

 

[PostFrameSE]

This has been a great conversation.......and frankly.........jayrod12 you've hit the nail on the head. "We are scared by litigation." I've not been involved in it in my 14 years as a registered engineer and I don't intend to go there. None of us do. However, some have been there, and I'm quite certain that once there, you'd really rather not go there again......at least if your neck was on the chopping block. Hence, the reservation I have to even appease a customer who is not being forced to build to code yet desires to have his project certified to whatever level he deems important to him. I'd like to accommodate him in that regard, but if there wasn't a liability risk, I would have never started this post. This group of engineers that comment on this site are fabulous. I appreciate each and every one who has taken the time to respond. I hope we've all benefited from seeing the various perspectives. I know I have. Thanks.

 

[dcarr82775]

I would agree there are always scenarios that can work. This is new construction, not some existing condition or stand alone garden shed. Disclaimers are fine things, but within reason. Seems strange to stamp something with the disclaimer that the design is grossly inadequate to support the code required loads.

I suppose if on the first page of the calcs in 70 point font says "This design does not meet code and is approximately adequate to support only 70% of the required wind load", it could work. Weird and pointless to stamp it, and nothing but a potential headache for the stamper, but to each his own.

 

[TLHS]

Jayrod,

I do all sorts of industrial stuff and strange installations with my own invented or client invented design requirements, but in those cases you have a couple of things:

1) There isn't a code or widely adopted standard that explicitly covers the scenario. That means there isn't a documented practice that a reasonable engineer would follow.
2) Often your client is knowledgeable and sophisticated. They are either engineers themselves or experienced in industry. They understand the design basis and consequences.
3) There is no access for the public in general.
4) There's generally a good basis for the loads and, if anything, conservative safety factors on the unusual loading. Low safety factors are justified and defined when they're used.
5) If the property changes ownership, there's likely records and the person who would be involved in operating the equipment will likely understand (1) and (2).

Number 3 might be true for an agricultural building, but 1, 2, 4 and 5 likely aren't.

For a building type structure in the US, ASCE-7 is the practice that a reasonable engineer would follow. You can certainly have reasons to deviate from it, but you've got to have a reason. Stamping something with an inadequate design basis seems like it's ignoring the most fundamental part of the structural engineering process. Developing the applied loads has the largest effect of anything in the design process (except possibly establishing the basic load path). Not establishing that those meet a reasonable level of safety seems like it would be bad practice. A stamp doesn't certify that the math is right. It means that what's been designed meets some reasonable level of safety and engineering practice. If I deviate from standard industry practice I need to explain why and then I own that deviation.

If designing an agricultural building to a lower windspeed seems reasonable, I can go ahead and stamp it, but by stamping it I'm certifying that I think it's a reasonable design practice. If something happens later on, I own that choice morally and legally. Pointing at a salesman and a layman owner because they gave me a design basis doesn't work.

I'm not saying that a lowered windspeed isn't defensible somehow, but determining and justifying that needs to be done by the engineer involved in the project.

 

[dhengr]

Your post of 15MAY15, 13:23 sheds some new light on the matter. I agree with the people who are giving good (ethical, etc. etc.) sound reasons for not doing this kind of engineering, thus my post of 14MAY15, 22:38. There just isn’t much in it for you except the likely headaches and liability. The new dimension is that it is your employer doing it to you, using you, your stamp, to sell a product at a lower price. If you let them and the salesmen start going down that road, pretty soon they’ll be beating the competition with 65mph wind speeds and half the roof load. We all know that wood products have fairly high factors of safety on their allowable stresses, let’s cut these by 30 or 40%, that won’t cause too many failures, and we can sell even more agri. bldgs. And, then when something does go wrong, the customer comes after the company and its insurer, and some smart attorney sees another insurer to split the cost with, and you, your stamp, and your insurer are quickly involved, for having signed the plans and calcs. The owner should be going after the company that sold and built the building, but you’ll be dragged into the fray because you signed the plans and calcs. And, at the end of the day all you really have is your good name, reputation and SE licence; and if the company gets ticked because your building fell down, you could be looking for work without those three things. And, it will quickly become your building in that kinda fight, you should have warned them that they were going just a little to far. You should be able to work within the company, and try to keep them out of serious trouble, but if they want to gamble (skimp a little or a lot) with loadings and design, they take the risk and defend you and the company and its products, and your name and stamp/license aren’t so exposed. And, you should talk with the boss about how they have you insured if you are acting as the company Structural Engineer.

 

[PostFrameSE]

Thanks dhengr. I am not an independent engineer. I am employed by the company that puts up the structures. That tends to make things a bit interesting as well.

 

[IRstuff]

Since your company is selling these structures, they fall under the "public safety" clauses of most PE laws, so the question will be what will you have to defend yourself with if the structure collapses on top of someone?

TTFN
faq731-376

Need help writing a question or understanding a reply? forum1529


Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
There is a homework forum hosted by engineering.com:

http://www.engineering.com/AskForum/aff/32.aspx