Contractor will not provide rebar shop drawings? 11

[Ben29]

I did a fairly simple project. It is a 1,500SF,1-story addition to an existing building. The foundation consists of strip footings and slab on grade with WWF. Our general notes require that rebar shop drawings are provided. Our General Notes read: "if shop drawings are not provided then our firm is not responsible for the structural certification and design of the project."

The architect told me that the contractor does not plan to provide rebar shop drawings. The architect asked me, "Are you OK with that?"

How do you answer this question?

They do plan to have a 3rd party inspector inspect the rebar placement.

 

[rb1957]

Humour the ignorant, please.

what would a "rebar shop drawing" show ?

the details ? ok, this is easily confirmed with on-site inspection.

the material ? is there only one ??

are the rebar details straight (and are bends separate pieces) ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[canwesteng]

Yeah, everything in rebar shop drawing is easily confirmed on a site inspection (same as pretty much any shop drawing)... good look getting work again because you held up 10 concrete trucks because you didn't review the rebar shops and something wasn't built right, so they need to fab a whole new set of rebar.

 

[Greenalleycat]

The US sounds like the wild west
Why are you inspecting with the trucks lining up and why are you getting blamed if they fuck it up
Even if they have the drawings perfect you don't know how they are going to build it so you'd need to reinspect anyway

 

[dold]

@RB,
Here's a link to an example. They provide layout, quantities, bend schedules, lap lengths, etc. It's literally how the rebar shop knows what material to cut, fabricate, and send to the site. On site, each bundle of rebar has a piece mark. So when the shop drawing (looking at the link as an example) says "place piece mark 4DO3 at 12" o.c." or whatever, the rodbusters go grab "4DO3's" out of the pile and start tying them. And the shop knows how to bend the 4DO3 pieces by looking at the bend schedule.

All that said, for a little home addition slab on grade or something with #4 at 24" o.c. and that's it (no special bent pieces, etc) the contractor is just going to buy a bundle of #4s and cut them up in the field. When it comes to larger buildings with complicated reinforcing then a rebar fab shop is 100% going to generate shop drawings.

@greenalleycat,
Wild west to me is not reviewing shop drawings. I just don't see how this is a difficult task or see the reason to NOT review them? That's the entire point of shop drawings: to make sure the supplier and installer understand the intent of the structural drawings. And to prevent and correct any misunderstandings before everything is installed.

Our office also ended up having to settle on a precast panel where the precaster had shown cast-in inserts on the wrong side, so they ended up being built on the outside of the building
Our fault? Not even remotely. Had to pay $30k because we'd looked at the shop drawings? Yep

This seems like a perfect example of how actually reviewing/checking the shop drawings could have prevented the inserts from being installed on the wrong side. If they show it wrong on the shop drawings and you make a note that it's on the wrong side, problem solved. If the shop drawings you reviewed show it on the correct side, then they install it on the wrong side, you can say "you installed it on the wrong side. Shop drawings showed it on the other side. That's on the fabricator". But if you review the shop drawings and they're wrong, and you didn't make note of the issue, and return them with a "no exceptions taken" stamp then yeah, you didn't do your job.

 

[lexpatrie]

"Yeah, XYZ Engineering f'ed up my job because they wanted rebar shops for (2)#4 w/ 18" laps. What a bunch of idiots"

Anybody with any skill at all in the "business" of general contracting is going to see right through that.

I'm a Professional Engineer, I'm in the "business" of health, welfare, and life-safety. I have zero concern with "losing" a rogue, incomptetent, lackadaisical contractor who treats sealed engineering drawings (and their requirements for submittals) as if they are "suggestions". If I lose a small residential contractor, that impacts me about zero. And I would do the same regardless of the financial impact to me. As is required of me, ethically. Somebody tries to pull this on a 50 story building, same answer.

Duty to report. Done.

Further, enabling this kind of behaviour just allows it to perpetuate. At what point is the job "too small to do correctly"? Contractors of this nature, and their contemptuous attitude toward contractual requirements (as well as licensing requirements), can get their job red tagged anytime and it won't bother me.

Imagine inspecting rebar after it's been placed and poured? What's your "generally accepted principles of mechanics" methodology there? Consulting a psychic? GPR? In-situ live load testing?

My tolerance may be reduced as I've had this kind of "attitude" on much larger projects. To the effect that they said they'd do the shop drawings AFTER they poured the concrete and the job was done. It did not go well for them.

Did they find another engineer for the next project? Yes. I still don't care. Health, welfare, and life-safety.

 

[Greenalleycat]

Sorry Dold, I strongly disagree with you

RE the inserts: we don't draw the shop drawings...but our own drawings showed the correct side. They fucked it up, not us.
We don't have a 3D model showing how these things go together which would show which side the inserts are on
We may check that the correct inserts are specced but it is not our responsibility to check every single minute detail - we have no budget or obligation to do so

Contractors are big boys and girls and they can take responsibility for their own choices
It absolutely baffles me that you would WANT to review their work - they're just reproducing what your drawings already show ffs
It is the contractor's choice that their methodology includes reproducing our drawings into their own format
We are not paid enough to take responsibility for their decision or to have the time to check every single thing
We only check critical structural things and our stamp reflects that - but when the lawyer bills start ticking up, it doesn't matter what your stamp says

 

[dold]

@Greenalleycat

I guess we'll have to agree to disagree then. Not sure what else to tell you other than this is how we do it in the US. It's in every set of drawings and specifications I've ever generated at several firms.

Do you not consider rebar a critical structural thing?

 

[Eng16080]

So, they don't want to provide shop drawings because the project is so simple? My take on that is:
[ol A]
[li]If the job is really that simple, why even argue about it? Just provide the shop drawings. Done. Like if I had a square slab on grade with a single layer of WWF in it and somebody wanted a shop drawing, I wouldn't argue with that. I would take the 5 minutes to make the stupid drawing.[/li]
[li]I can't think of a single project I've ever worked on where I didn't find problems in reviewing shop drawings. In those cases, the problems were caught early when they were easy to fix and only cost my time, rather than several peoples time at the site plus potential material plus (more of) my time. This is one of the reasons I like designing with steel. Most of the time, the quality control of having a shop drawing review works really well. Then you go to the site and see the butcher job they did with the wood.[/li]
[li]Continuing my last point, sometimes small ("simple") projects are the worst with this kind of stuff. I've caught outrageous errors reviewing steel shops for such jobs, stuff that would be awful to try to fix on site.[/li]
[/ol]

In terms of requiring rebar shop drawings, that isn't something that I explicitly require for most projects (although perhaps I should). For OP, though, you already require it, so are you going to resubmit the plans now with the note omitted? I would bet my dollar that if the note stays and you tell them it's ok to proceed without the shops, and there ends up being an issue later, you'll be blamed.

Our office also ended up having to settle on a precast panel where the precaster had shown cast-in inserts on the wrong side, so they ended up being built on the outside of the building
Our fault? Not even remotely. Had to pay $30k because we'd looked at the shop drawings? Yep

Crazy! We had the same thing happen on a job several years ago. The inserts were on the wrong side and they went ahead and installed several panels reversed. The owner of the prefab company tried to convince us and our client that it would be ok that the lower level windows built into the panels wouldn't be aligned with the 4 stories of windows above. That didn't go over well.

 

[Greenalleycat]

@Dold, that's a loaded question
Of course rebar is as structurally critical here as it is everywhere
The discussion seems to be around the means of quality assurance to get that rebar correctly built

The process here is to produce structural drawings showing what is required, then to check the real-world reinforcement installation for non compliances
We inspect every pour as the means of quality assurance
If it deviates from the drawings, contractor's fault. They pay to fix.
I do not know of anyone that checks rebar shop drawings

The impression I have is that in the USA you guys produce structural drawings, then check the drawings that someone else produces of your drawings
It seems that the primary quality assurance is you checking that the guys copying your drawings haven't fucked it up
It seems to be uncommon for inspections to be undertaken prior to pouring the concrete? So the QA process doesn't include sighting what is actually built

Maybe I've misinterpreted it, but from where I am sitting, our way makes a lot more sense...

 

[Smoulder]

I side with Greenalleycat. Shop drawing review is error catching effort in good faith. Shouldn't be more liability for us. And always one way traffic. Contractors not liable for not flagging our errors before showing up at site even though they've reviewed the drawings and are qualified and experienced.

 

[human909]

While I do do agree a fair bit with Greenalleycat, I think the biggest lesson here is that things are done differently in different localities. Most of the time is just the peculiarities of history, codes and contracts combined with and industry that is very conservative to change. (Most of the conservatism comes from the vertically separated design and supply chain. To enact change all or half the chain needs to get on board.)

I think believer Greenalleycat is AU/NZ. While I do think we do alright down here, we no doubt have our own peculiarities.

IMO, the US generally has more because it is a more inward looking ecosystem that doesn't look outward at world's best practice. {*COUGH* METRIC SYSTEM *COUGH*). That said the US is miles ahead of us minnows down south in terms of research, codes and industry bodies. (I recognise the irony of using the word miles here)

The reason I don't like it is I think you take far more liability as a consultant (no matter what wording you use in your stamp) and it allows the shop drawers to turn their brains off
I have had drawing reviews where I have rejected 60%+ of the set - that isn't valuable review to prevent mistakes, it's just laziness by the contractor

I completely agree here. The last thing I want to do is review shop drawings for the exact reasons stated. Increased liability for minimal reward.

Wild west to me is not reviewing shop drawings. I just don't see how this is a difficult task or see the reason to NOT review them? That's the entire point of shop drawings: to make sure the supplier and installer understand the intent of the structural drawings. And to prevent and correct any misunderstandings before everything is installed.

I also agree here. And this came up for me last week. The client asked me to review the drawings and I replied I hadn't included that in my fee. I explained to him that I would do it if he wanted to cover himself, but it wasn't required. I pretty much encourage him not to give me more work! He ended up choosing the cautious option and requested the review. Mistakes in shop drawings were identified and corrected.

I got a additional fee and the contractor won't have a massive lawsuit if 0.2% seismic event happens to occur.

 

[XR250]

"Yeah, XYZ Engineering f'ed up my job because they wanted rebar shops for (2)#4 w/ 18" laps. What a bunch of idiots"

Anybody with any skill at all in the "business" of general contracting is going to see right through that.

I will respectfully disagree with that.

Imagine inspecting rebar after it's been placed and poured? What's your "generally accepted principles of mechanics" methodology there? Consulting a psychic? GPR? In-situ live load testing?

Review of shop drawings will not fix field errors or incompetence.

 

[JAE]

A few thoughts from the midwest USA:

1. Review of shop drawings is intended to check for general conformance to the plans/specs and not to verify every dimension, note, etc.

2. This is an effort to verify that the contractor - and their support entities - appear to correct interpret the EOR plans.

3. It's also to have a second layer of review for complex portions of the design - in the OP's case - not really complex at all, granted.

4. Our general conditions on our projects (found in the specifications) always indicate that review of submittals is only a general conformance review and the contractor is fully responsible for compliance with the plans and specs. The review doesn't shift any original risk to the EOR that wasn't already there.

5. In the US - the AISC specification includes an entire section discussing the EOR's responsibilities in reviewing shop drawings - ACI has similar provisions - so this isn't something that some US engineers just dream up to do - it's embedded in the construction industry.

6. Finally - for a simple rebar check of a slab like the OP posted - I'm not sure a review of rebar shops is all that needed. To have a "standard" note requiring shop drawings on every project, no matter the size, doesn't seem like a best practice.

 

[wth]

Interesting discussion for how rebar is handled in different parts of the world. Seems we're in our own category as we actually produce the shop drawings and rebar schedules as part of our design. Which is starting to feel more and more meaningless as we model it all in 3D anyway.
We also don't do site inspections as part of the design fee, the contractors build, and we design.

 

[Greenalleycat]

Amazing that you guys are so trusting of your contractors
I wouldn't trust 90% of the contractors I work with as far as I could throw them and I would never, ever assume that the building matches the drawings the contractor provides me
The amount of shit, non-compliant, and simply wrong construction I see every week would never allow me to put that much trust in them!

 

[wth]

In our case it's simply not our job or responsibility to verify that they follow our drawings, the contractors are responsible for their delivery, and are subjected to mandatory 3rd party inspections for load bearing structures. It's not perfect, as the inspection mainly focuses on quality control and systems, but it forces everyone to have a decent quality assurance system.

 

[human909]

Interesting discussion for how rebar is handled in different parts of the world. Seems we're in our own category as we actually produce the shop drawings and rebar schedules as part of our design. Which is starting to feel more and more meaningless as we model it all in 3D anyway.
We also don't do site inspections as part of the design fee, the contractors build, and we design.

Where are you located?

We also don't do site inspections as part of the design fee

As a sole practitioner I don't do site inspections as part of the design fee either. And from most small or medium sized consultancies are the same in my experience.

I also work for a design and build firm. We do mostly steel and mechanical equipment and have high faith in our trusted and skilled contractors that we use. I inspect when I get the opportunity, but I don't feel much urgency regarding it. Recently we've been had civil works done and have felt the need to watch the contractor EVERYDAY. Ideally it shouldn't be like this, but this is design and build and the buck stops with us.

 

[Greenalleycat]

Very interesting the different approaches round the world
Here, engineers are very hands on at the job site (well, maybe feet on. I picked up a shovel to clear some dirt the other day and the contractor told me they'd never seen that before...)

I will say there's also a big difference between resi and commercial
Commercial crews are typically much, much better and some of them could be trusted to build something 95%+ right off correct drawings
But there are still PLENTY of cockups on commercial jobs that fully justify engineering oversight
Residential...yeaaaaa

Engineering fees here are usually a fixed fee for design and drawing, then construction monitoring is open ended

 

[wth]

Where are you located?

Norway, it's worth mentioning we also have a pretty extensive national annex to Eurokode 0 covering quality control requirements for both design and construction for different complexities.

We don't have any design and build firms, no contractors have in-house design departments, except maybe small residential firms.
We do a lot of design and build jobs, but then we're designing for the contractors.

 

[AaronMcD]

We always require rebar shop drawings, no matter the size of the project. On small projects, we often don't see any or expect to see any. Sometimes we don't even get steel fabrication/erection drawings. And sometimes when we do, the shop is so small that the "shop drawings" are just copies of our details and don't even have parts listed. We don't make a huge fuss about it in most cases.

We always perform the required structural observations, including rebar and embedded items prior to concrete placement, wood framing and connectors, and steel framing. Our observation is more important than special inspection, because the inspectors always miss stuff and aren't familiar with the design.

If they want to finish the project, they need to do what we want. The city requires a letter from the structural engineer. We ask for all inspection reports and verify before signing off at the end of the project.