Who is responsible fro the architects design? 1

[SteelPE]

I do fill in work from time to time helping steel fabricators with the design of their stairs. I was recently asked to look at a project with a high profile engineer and architect. The projects consists of what I think is an addition to an existing building. The architect has a very specific set of requirements as to what the stringers, railings and guards are to be. The architect is so specific that they call out the size of every little member to be used. Being an addition, I think they are trying to match materials used within the existing building.

Now my client bid and won the project and is being asked by the engineer to provide a set of calculations for the misc iron package. That would be fine, however, some of what the architect is asking for doesn't work structurally. Seems like the architect and engineer didn't really think this paradox through. If they required engineering then they are open to their sizes being changed...... but they require the sizes they show.

Usually, with my help, they can fight these projects off but I don't think they are going to be successful here.

I know asking for a set of engineering calculations is standard for misc iron, but is it standard to require those calculations when the architect is this specific?

 

[msquared48]

The Architect can be as "specific" as he wants, but if it doesn't work structurally, then it does not work.

HE will have to bend a little, or the stairs will bend a lot. His choice.

Most Architects I have worked with are more reasonable, providing some latitude. Tell him to do the calculations and stamp it. See how far he gets.

Mike McCann
MMC Engineering

 

[cliff234]

That's not a paradox. That's a mistake (if the sizes shown on the contract documents don't work). Sounds like a change order for your client. Communication is getting worse and worse in our profession. The architect shows sizes but seemingly never asked the structural engineer if the sizes are ok. The engineer requires stair calculations, but does not look at the architects drawings close enough to see that sizes are called out. I would think that if the sizes are called out then there should be no need for calculations, but thankfully calculations were called for - and you caught some undersized members.

 

[nutte]

Undersized by calculation, yet perfectly adequate if the long successful performance of similar handrails is worth anything.

This same thing has happened to me, where the architect calls everything out, but they still want the fabricator's engineer to provide calculations, and then the members don't work. Every time, when this is brought to the architect's attention, they defer to us and the member sizes are increased. It doesn't make any logical sense, but that seems to be the way our industry operates.

 

[SteelPE]

In the defense of the architect, I was asked to look at the project so I haven't run any calculations. I have my suspicions that something is not correct with the sizes that I am seeing though based upon my experience. I just find it odd that the architect would tell you what he wants and then the engineer would say "prove it" to a third party engineer who has nothing to do with the project.

I've talked this over with my client. We are going to run the calculations as they currently shown and when something doesn't work, we are going to change the sizes as necessary to get a system to work. They will then fight it out with the architect.

 

[msquared48]

Good choice.

Mike McCann
MMC Engineering

 

[JStephen]

On similar issues in completely unrelated work- I find the best approach is to ask (or have the contractor ask, in your case) the customer as to who is responsible for the design. Sometimes, a lot of thought has already gone into it, and there's no reason to re-invent the wheel. Sometimes, you'll have very specific information with a PE seal there on the page, and it's just a bunch of lines slapped on paper that nobody has even thought about.

 

[TDIengineer]

The architect is responsible for their design. If you're designing the structural portion, then that's your responsibility.

If your stamp is anywhere on the drawing, and there is a problem, you're named on the law suit.

 

[XR250]

The same thing happens to me all the time except it is with light gage steel and the EOR has stamped it.

 

[SteelPE]

Excel,

The lightest steel I design would be girts and purlins. I don't do studs and in fact exclude their design in my proposals. There is a bit of a difference though, the architect is calling out what he wants to use because it either matches what is in the existing building or he "likes the look" of what he showed. What I don't get is, either call out some generic sizes (steel plate, steel rail, steel stringer etc) and let the engineer decide what to use, or call out the sizes and don't require a third party engineer.

As mentioned above, this has opened the owner up to a back charge from the fabricator. Usually this would be squashed by the GC but I'm sure there will be some sort of compensation which will end up coming from the owner.

 

[XR250]

Agreed. I get EOR's calling out sizes, gages and connections, but still want it engineered by a third party.

 

[archeng59]

In my opinion, the architect and EOR are responsible for making certain that what is on their drawings meets code. Even if a third party designs something for the project per a performance spec, the architect/EOR is responsible as the prime design professionals.

 

[steellion]

I've seen this before where the architect has indicated specific stringer sizes without any calculations to back it up because that's the look they wanted. Do not assume these stringers have been designed. Design the stringers based on what is needed structurally.

 

[PUEngineer]

Were the stairs shown on the architectural drawings or the structural drawings? If it's not on the structural drawings then I don't see how the EOR is responsible for those sizes.

Our typical projects are bid with performance specified stairs, which is an architecturally authored specification. If the architect attempts to dictate sizes on their drawings, then I wouldn't attempt to review those sizes, knowing that it would be engineered per the engineered stair specifications. If it's in our contract to consult on the engineered stairs then that's another story.

I would expect the architect would have to be flexible if something couldn't be engineered to work as they'd shown. Just like during the design phase of the project.

 

[JLNJ]

In casees like this I do my best to have it both ways. I note that the architect wants a certain "look" is the structural sizes are representative of the architect's intent. I note that the third party guy is responsible for the final engineering and design and needs to negotiate the "look" with the architect to best match his original intent. I put this on the structural drawings without necessarily telling the architect. In some cases the smart guys might actually save themselves money - such as when the architect calls out 1 1/4" stainless standard pipe handrail but can make do with 1 1/2" OD stainless thinner wall tubing.

These notes are definitely not foolproof. If the real, final design has to veer way off the intent you still may have a contractual disagreement, but at least the bidders know as much as possible what they are getting in to up front.

Similar, or sometimes worse, problems can arise when the physical space alotted is not adequate for the stair.

 

[Bagman2524]

We've had cases where we bid on projects based on the sizes the Architect has shown which later turn out to be too light. The contract people then need to fight it out over who's paying for it.