Shop Drawing Review Question 3

[SteelPE]

I don't know if I have already asked this question before (sorry if I did, but I couldn't find it during my one minute search of my previous posts).

I am in the process of reviewing the shop drawings for a large warehouse. We have been sent the shop drawings for the open-web steel joists and I was a bit surprised to see over a 400 page submittal. Upon further investigation, it appears as if the manufacturer has forwarded me all of their joist calculations (basically a data dump). I was a bit surprised by this as in my 20+ years in the business, I have never received such a submittal for a shop drawing review from a joist manufacturer standpoint. I don't know what the purpose is. Certainly I don't have plans of reviewing 400 pages of mindless calculations. Is this something open web steel joists manufacturers are doing now?

Currently we are indicating that we will not be reviewing the submittal after we are done with the JE drawings.

 

[JLSE]

Don't you usually stamp general conformance anyway? Would it hurt, just to verify the design criteria, member spans and supports, and stamp it if good?

 

[SandwichEngine]

I can't speak for joists specifically but I work for a PEMB company and so the process would be similar.

The first thing is whether or not their design team was instructed by their contract to provide calculations. Most of our jobs require them. If that's atypical for joists, it could just be that a new person was filling out their order sheet and accidentally checked that box.

As for the length of the calcs, joist calcs will be just like any other set of calcs in that you can get the short-short version, the regular version, the long version, etc. Most wouldn't want to receive our long version because it's checking every single weld, plate, bolt etc. for every single load combination and for multiple combined failure modes. For a decent sized metal building that could be thousands of pages. Because of that, we send a short-short version that basically just says what loading we designed the building for, basic geometry, etc. Every now and again though, someone will want a longer version so they can review every unity check and personally verify that none are over 1.0. No idea why but when that happens we send them a longer version that shows all that information.

I haven't needed to do this in many years but I remember a few times where the EOR decided it was their job to audit every calc that goes into a PEMB. In response we sent them "the Greater New York area phonebook." The longest possible set of calcs we could generate in the hopes of getting them to realize that verifying every single part of a delegated design in a specialty they aren't familiar with isn't a good use of their time.

It could be that either someone made a mistake and accidentally generated the longest version of the calcs or something else about the project made them think it was Greater New York Area phone book time.

 

[gte447f]

Are the calculations stamped by an engineer. If not I would not review at all. Reject and require a resubmittal. If they are stamped, I would look for design criteria used by the delegated design engineer (design loads, deflection criteria, anything special, etc.). If that info is not easy to find/identify within the 400 page data dump, I would kindly request a resubmittal with cover letter(s) listing the design criteria for each design.

 

[JedClampett]

In my big list of grievances, that's one of my joist ones. Our specifications used to ask for calculations for OWSJ. After 5 or 6 DOS based indecipherable computer vomit calculation packages, where I couldn't even verify the end reactions for correctness, I started:

[ul]
[li]Not specifying OWSJ as much (almost never).[/li]
[li]When I absolutely have to, I just specify the standard K joists.[/li]
[li]I stopped asking for calculations.[/li]
[/ul]

There were other reasons to stay away from joists, but it was mostly it was aggravating experience. We would put depth of the joists down, the contractors would say we can't bid without depths plus sizes. We would put preliminary sizes down, the joist supplier would say we have to provide that size joist, even though we clearly stated it was for pricing only.

 

[Brad805]

We have never had an issue with Canam or Nucor shop dwgs. I review the load diagrams on the calc sheets. Canam does not produce joists unless calcs package sent back as reviewed.

 

[JoshPlumSE]

The first thing is whether or not their design team was instructed by their contract to provide calculations. Most of our jobs require them. If that's atypical for joists, it could just be that a new person was filling out their order sheet and accidentally checked that box.

For PEMB, I think this is reasonably common. But, that's because the contracts are all over the place in their requirements. Right?

For joists, my impression is that the engineer chooses a joist designation out of a catalog. And, the manufacturer provides a joist that meets the loading requirement in that manual. Based as much off of testing as calculations. Different manufacturers will build the joists slightly differently. But, they are all saying that the joint meets the load requirements of the one specified in the SJI tables and called out by the engineer.

Now, if you have a non-standard joist. Like an Joist Girder or something like that. Or, a joists that have very non-standard loading. In those cases, maybe a calculation could be warranted.

 

[JedClampett]

As for the length of the calcs, joist calcs will be just like any other set of calcs in that you can get the short-short version, the regular version, the long version, etc. Most wouldn't want to receive our long version because it's checking every single weld, plate, bolt etc. for every single load combination and for multiple combined failure modes. For a decent sized metal building that could be thousands of pages. Because of that, we send a short-short version that basically just says what loading we designed the building for, basic geometry, etc. Every now and again though, someone will want a longer version so they can review every unity check and personally verify that none are over 1.0. No idea why but when that happens we send them a longer version that shows all that information.

I'll tell you why: We have long term clients, utilities and the such. And they occasionally want to modify a PEMB building that we specified way back, place a load in a new place, route a pipe. So we need the calculations to check this. Now in a perfect world, we could call you, send you a small fee and you'd tell us. But due to floods, fires, pestilence and just don't want to, that never happens. So if we don't ask for the calculations right off, we're never going to get them.
Now don't get me wrong, they're still impossible to use, but I'm still hoping.

 

[structSU10]

Here is one part of a multi part series on submittal review that is worth a read:

https://www.csiresources.org/blogs/...drawings-and-submittalsdelegated-design-submi

 

[phamENG]

For joists, my impression is that the engineer chooses a joist designation out of a catalog.

That's the "old way" of doing things. Seems to have really switched over in the last few years after I left commercial design. Now they're all about depth and load specs and allowing the joist manufacturer to design a finely tuned watch. Recently, with joist lead times measuring into years and freight costs skyrocketing, probably makes sense to shave as much cost/weight as possible since most of these are trucked over long distances to the job site.

SteelPE - only had something similar happen with joists once. I was a junior engineer and lugged the stack of papers, confused, into my boss' office. He had me stamp it "received for file, not reviewed" and move on with the shop drawings and summary sheet.

 

[XR250]

That's the "old way" of doing things.

I liked the "old way". I'm not sure I like the "new way" of anything lately. Then again, I'm still using the green book

 

[DrZoidberWoop]

The contract document your company developed and signed is everything. We explicitly subcontract stairs and OWSJ's, which includes thorough exculpatory clauses and specifically excludes shop drawing review for the subcontracted structural elements.

Edit to add: Post below me is correct on all counts.

 

[Brad805]

Unless I am mistaken, Dr. Z represents a fabricator. That setup is common. Shops are sent to the EOR for review. GC or customer is expected to check for general dimensional conformance.

I am sure SteelPE's dwgs are very well done and easy to follow, but it is worth looking at the question from the perspective of the supplier. There are ton of exceedingly poor EOR dwgs they are stuck dealing with. In my role as a delegated designer I see them. Structural dwgs with zero dimensions anywhere and architects that show the most useless dimensions you can imagine. The suppliers we deal with are large companies with policies. What do we expect them to do? If the EOR does not review them, who does? This project sounds like about 200 joists or so. If you have your stamps setup in bluebeam and do your review electronically this sounds like about 3hrs. If your rate is say $150usd/hr this should be in the realm of $500 or so. Avoiding one mistake will pay for that cost if the site crew (men and crane) is worth say $500/hr. That does not include the time you argue about who made the mistake, or who pays for what.

The standard joist concept went the way of the doe doe bird eons ago in our area. Canam rolls their own profiles and has beat down the weight of joists down. Do I agree with that, no, but everyone price shops.

This volume of paper is not large for wood truss package. We recently got a 200page truss package set for a project that is likely 25% the size of this warehouse.

Contractually most have a contract with the owner or architect. I suspect Dr. Z has a contract with the supplier.

 

[SteelPE]

So this is a rather large warehouse with, "from my standpoint", hundreds of the same joists over and over and over and over again. We have specified everything the have needed (joist size/designation, seat rollover capacities, roof uplift etc) on the drawings. Now, I say "from my standpoint" as the manufacturer may change piece marks depending on the roof slope of whatever they would like. It's not like I have given the manufacture a roof load and a bunch of lines to represent joist locations and said to them "the design of the joist is up to you". They are designing a joist that we selected from a catalog (say a 28K10 that's 48' long). I don't think it's that complex.

This fabricator has been a PITA. They haven't coordinated a thing with the joist manufacturer... or even incorporated a single RFI into their shop drawings and the GC is just putting a rubber stamp on everything and sending it down to the engineer for review. The whole project is turning me sour on this particular fabricator as I have never had this many issues with the other half dozen fabricators in the area.

 

[dold]

That's the "old way" of doing things. Seems to have really switched over in the last few years after I left commercial design. Now they're all about depth and load specs and allowing the joist manufacturer to design a finely tuned watch.

I've switched over to giving joist depth and uniform load (e.g., 24K (240/120)). For non-standard loading, I'll provide a diagram, or enough information for them to design it to their liking. E.g., I'll just draw in the snow drift width/Pd/extents straight onto the framing plan. Ditto for point loads, etc. This is opposed to designing each joist on my own, which becomes a pain when you have a diagonal bearing wall or something where each joist is a different length.

I've gotten a little bit of grief from GCs since it makes it a little more difficult to price the joist package, but it speeds things up on my end and my understanding is that it makes the joist designer's life a little easier. Inputting the joist span and loads into their software is all they do when the info is presented in this "new" way. Otherwise they have to kind of back calculate/look up the allowable loads for a 24K7 and tailor those loads to the specific span since a difference of 4" in span can lead to a slightly lighter chord member, for example. Spec'ing a 24K7 isn't the same as spec'ing a W24x55. Each one (or each 'group') is unique to the project. 24K7 is really just a load spec.

Different strokes for different folks. And markets...I guess.

 

[Aesur]

I would say it is fairly common in my area to have a joist package that is over a few hundred pages, same applies to wood trusses and I-joists, in fact we recently received a wood truss package with over 2000 pages. Typically we glance thorough and verify a few joists for loading and note as such on the shop drawing stamp, we also like to look for unique loading or other conditions, ie drags. Some jurisdictions in my state are actually starting to require all deferred submittal items be submitted before a permit is issued, not sure how this is going to play out yet as it has the potential to cause owners to just stop building locally due to the headaches and up front costs of doing this. There is also a discussion underway of requiring the EOR to review EVERY calculation, plan and layout generated by any deferred submittals, if this goes though I could see construction admin fees being higher than design fees...

It is worth noting that I am starting to notice that contractors are doing less and less coordination and saying "not my job" for shop drawings and deferred items.

 

[Brad805]

It is frustrating when others are not doing their part. We had a project like that in the spring. I was not the EOR, but our client was supplying parts that would be affected by joist alignment errors. I found about 10 joist discrepancies that would have caused us endless hours figuring out how to fix the mess later. I am constantly amazed how few GC's read the fine print on our stamps and check things. Ahh, how times have changed.

If they are using your part marks and it is from tables, I think you could skip viewing/stamping any of their calc sheets. If the fabricator has their own engineer you could kick it back to them. Presumably this is one of the big suppliers. Do you know their policy? I do not find reviewing the calc sheets exceedingly time consuming. The vast majority of the joist loading is the same, and we are only checking for general conformance.

My question was more general in nature to those who are staunch advocators of not reviewing these. I knew your dwgs would be good, and I expect most others here are as well based on their discussions. Many in the real world are not and the joist company policies are based on the worst offenders.

 

[JedClampett]

It is worth noting that I am starting to notice that contractors are doing less and less coordination and saying "not my job" for shop drawings and deferred items.

Less than nothing? Are they changing the submittals to make them worse?

 

[Aesur]

@JedClampett - I am noticing that contractors are just rubber stamping the submittals before they go to the engineer/architect and they are refusing to field verify dimensions or coordinate with other parts of the project for conflicts, relying 100% on the EOR and Architect to do so, which also doesn't get done as their reviews are for conformance only and typically only review loading and maybe special dimensions, but not everything.

Can you imagine how long it would take to review a 400 plus page of submittals, especially when the layout needs to be reviewed as well.. that's easily a few days to a week worth of time and the EOR would not have a CA fee that covers that.

The contractor is supposed to build the "final" structure that EOR shows, the EOR may not show every joist, but it is the contractors job to coordinate those detains with the manufacturer and their engineer. It seems more and more often the EOR is now having to review and coordinated not only the calcs for each joist but also the entire joist layout for any conflicts with MEP or even skylights, that IMO is the contractors job.

 

[Brad805]

"There is also a discussion underway of requiring the EOR to review EVERY calculation, plan and layout generated by any deferred submittals..." Aesur, is that your state Engineering Board or whom is talking about that?