Shop drawing dimensions 6

[haynewp]

I usually put a note on shop drawings for the architect and the contractor to verify all dimensions. Especially plan dimensions for example on base plate and steel shop drawings. This is because I don't always know if a dimension has been changed and I was not notified of it.

If there is a dimension on the shop drawings that contradicts the structural plan and architectural plan dimensions that you have been given, what is the proper way to handle it?

1)Write in the dimension the shop drawings you have based your design on and is correct as far as you know, and put a note for the architect to verify.


2) Circle the dimension and put a note for the architect to verify.

 

[JedClampett]

"1) Write in the dimension the shop drawings you have based your design on and is correct as far as you know, and put a note for the architect to verify."
I like to give the contractor (architect, in your case) a number to work off of. He can then figure out why there is a discrepancy.

 

[haynewp]

Yes I agree, but I am afraid that the architect will not verify the dimension I have placed, the dimension I write in is not the most current, and the steel will be fabricated by the wrong dimension.

I am actually afraid this may have already happened.

 

[ChipB]

Having worked as an Engineering Manager for a Steel Fabricator (unless you don't have a family, and like working for an hourly rate that, when you work it out, is less than you were making as a new graduate, DON'T Work for a fabricator!), when I received shop drawings back which the EOR had marked "Architect Verify", if there was no answer, I would generate an RFI and wait on the answer before I sent that steel to the shop.

Some Fabricators have notes on the shop drawings that state something about all unanswered "verifies" are assumed correct and they accept no responsibility for field work as a result of this. The guy that owns the company I worked for thought that this was BS and should be handled more as a team effort and not pointing fingers at one another at the end of the project. I still think that was way cool.

Anyway, bottom line is, as long as you asked for it to be verified, you have a paper trail covering your butt. I never let an architect detail a baseplate because they are typically unaware of the oversize hole requirements.

 

[connect2]

we always make it the Contractors responsibility to verify site conditions or dimensions and report any dimensions that are outside the permissible anchor bolt placement requirements. After all its the contractors responsibility and the trades they hire to perform the work in accordance with our specifications. we do not field measure anchor bolt placement for fabricators or general contractors, however we end up dealing with their screw ups fairly often.

 

[jheidt2543]

My understanding of haynewp's question was that the ARCHITECT refuses to verify a design dimension. And, in the case where haynewp notes the correct dimension for his design, not knowing for sure if the ARCHITECT has changed it for some reason, he requires that the dimension be verified by BOTH the ARCHITECT and the CONTRACTOR.

Most of my career has been on the CONTRACTOR side of the project and most of my time has been spent trying to get the ARCHITECT to verify his design dimensions. I never had a problem taking responsibility for verifing field dimensions, the problem is getting the DESIGNER to at least put SOME dimensions on their drawings. It has gotten so bad that some structural's aren't putting dimension on their drawings at all! They have a note to "See Architectural Drawings for Dimensions". THIS IS DESIGN?

I like haynewp's solution, put as much information as possible on the drawing and ask BOTH the ARCHITECT and the CONTRACTOR to verify it. It is supposed to be a TEAM effort. Once you start trying to CYA, the system breaks down and problems really start. After all, the designer has to figure the dimensions to finalize the design in the first place, why hide that information from everyone else involved in the construction project?

Bye the way, once the screw ups start, there is usually enough blame to go around. I always try to head them off before they happen, it is a lot cheaper.

 

[connect2]

Hardly a CYA situation. The Architect defines the dimensions, we translate this into a grid with anchor bolt placement, structure in relation to ... as is Haynewps querry. If a set of shop drawings comes back with questions of dimension or elevation we review our drawings and if the info is on our drawing we state 'please review project drawings', if the info can not be found on our drawings then we will provide the info on the shop drawing review. shop drawings in our case flow from the trade, to the general, to the architect, to us, and then back out the other way after all review. All get a look at it, all get their two cents worth, as it should be. But yes we have an all encompassing statement to verify all dimensions with site prior to fabrication. We don't place anchor bolts. It is prudent for all to ask that the site verify bolt placement. It is our responsibility to deal with misplacement outside of the permited tolerances, a fairly frequent occurrance that despite all the above 'prudence' only shows up as the columns are checked for plumb. jheidt2534 not sure where you are, but comment wrt. 'structurals' as rather hmmmmm.... odd?

 

[jheidt2543]

Yes, strange as it sounds, on three different projects, with three different design firms, in the last four years, all the building dimensions were on the architecutral drawings, none on the structural. The structural drawings did show the column line grid with column line numbers, but no dimensions. Even many of the structural details were drawings only, no dimensions. You had to turn back to the architectural drawings to find the dimensions. Two of the projects were multi-million dollar jobs, I just hope this is not a trend!

 

[connect2]

Well for sure those drawings wouldn't meet the requirements of our building code, nor standard of practice expected ... wild!?

 

[Dinosaur]

Can a situation like this be handled by marking the correct (as per structural plans) dimension on the plans asking the fabricator to supply documentation why his dimension varies and then mark the plans correct and resubmit?

I am also frustrated that nobody wants to be a team anymore.

Dinosaur

 

[SperlingPE]

I work in an A/e (lower case e on purpose) office. There are (4) structural engineers and (1) technician [& 25 architects or architectural designers]. We stopped dimensioning the structual plan drawings about 5 years ago. The constant changes to the base plans, shortened schedules, and the age of instant communication made it difficult to keep up with the architect's changes. This shouldn't happen in a full service A/e firm but that is another discussion. We reasoned that it was better to have the dimensions in one place to avoid conflicts on the drawings. This is working in our office but we do hear the grumbling by the contractors or surveyors. Recently, we started doing structural work for outside architects and came to understand that this is not the norm. For the architect clients, we have asked that they dimension their own project but we will show the dimensions on the structural drawings and not on the archtiectural drawings [put the dimensions on a layer by themselves that can be turned on/off]. This has worked well for three projects.

 

[jheidt2543]

SperlingPE,

Thanks for the backup and your explaination. I understand your problem, however, I can't say that I agree with the practice at all. The additional time this causes everyone else in the construction process is enormous!

The bid take-off time is increased 25%-50%, the chance for field layout errors, as noted, is increased substantially, the amount of time required for those preparing shop drawings is also increased. Just the added time you spend on the phone working out the problems is worth something too.

You solved the problem your in-house architects created by pushing it on the backs of everyone else down the line. I think you should have a serious talk about office operations with your architects, before contractors start raising your bid prices to cover the added time.

Just my two cents, hope you get back on the team!

 

[connect2]

In Ontario the structural drawings can not be submitted in such a state, for Building Permit application, all necessary 'Dimensions' and 'Elevations' must be contained on the drawings. Such is the Regulation, such is the Law. Our firms drawings though do contain a statement that 'All Parties shall verify dimensions shown on the drawings with Architectural drawings .... and the Architectural Dimensions shall govern ...'. To be an effective team, everybody has to do their job in good faith. Architects change their plans alot, and we find generally, not always, the Contractors interest in the 'team' goes out the window when as the 'sucessful' bidder, {read low bidder) he finds out how much money he left on the table.
In any case i believe the question is with regards to dimensioning on structural drawings. we try to provide all necessary dimensions on our drawings, they don't go out the door otherwise. Architects change things, such is life, and its really just a business matter between us.

 

[samdamon]

I would not be comfortable omitting dimensions on my structural plans. The resulting potential for late or uncoordinated changes could affect everyone involved, including the building schedule and probably the bottom line for the Engineer.

If the grid or other dimensions are modified after drawings are issued for construction and the Engineer is unaware of it, what's shown on the struc drawings may not work anymore, and this may not be discovered until the shop drawings have been submitted. This could be true even for something as simple as a change in an edge of slab dimension. Uncoordinated dimensional changes also could be missed during the shop drawing review. If that happens, then I wonder if with no indicated dims on the struc drawings there is a potential liability issue.

Contractors who are fabricating and erecting a building need to look at both architectural and structural drawings as they do their work, but IMHO in the end, they should be able to to do the vast majority of the structural work just by looking at the structural drawings. At least that is the ideal.

Having said all that, the stated reasons for omitting dimensions (Rapid repeated changes on the architectural side) are understandable. If some of your architectural clients have a permanent habit of doing this, talk with them about it. If the changes are not driven directly by the Architect's clients then maybe the Architects can modify how they work. Otherwise, perhaps its time for the Engineer to do some marketing and find other clients. (Easy to say, I know).