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Contractor will not provide rebar shop drawings?
11

Contractor will not provide rebar shop drawings?

Contractor will not provide rebar shop drawings?

(OP)
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.

RE: Contractor will not provide rebar shop drawings?

Tell them you need to do a pre pour inpsection for a day and charge them for it.

RE: Contractor will not provide rebar shop drawings?

Can your firm be "not responsible for the structural certification and design of the project"?

If there's a lawsuit that is in any way related to the rebar, I'm pretty sure the GC's and owner's lawyers would try to get around that and come after your firm.

RE: Contractor will not provide rebar shop drawings?

Is the rebar that complex for a 1,500 sq. ft. addition that the building inspector can't verify it on-site?
Probably the reason he ain't providing drawings.

RE: Contractor will not provide rebar shop drawings?

I agree with XR.

Do most in the US check dimensions or verify for general conformance only when checking rebar shops? The rebar shop reviews I see are not of great value in my opinion.

RE: Contractor will not provide rebar shop drawings?

On a very simple project, the contractor may purchase rebar in 30' lengths and cut it on site. Hence, no shop drawings.

But to answer your question, if you are not paid to do a site visit and do not receive shop drawings, how can you certify the project was built according to plans? Can the contractor at least take photos for you to review before the concrete is poured?

DaveAtkins

RE: Contractor will not provide rebar shop drawings?

I don't think you can get off the hook for the structural sufficiency. However, inspection of the bar placement and certs for the rebar verifying the strength should be adequate to ensure the structural capacity is met.

RE: Contractor will not provide rebar shop drawings?

OP,
This point has been made but I will ask, are you comfortable with "the structural certification and design of the project" without review of the rebar drawings? With the sign-off of a 3rd party inspector? With pictures taken of the rebar prior to concrete placement?
If the answer to these is no, I would let the architect know that the rebar drawing review is to keep from you billing for an additional site visit and see what their response is.
I was involved with a project (heavy industrial, so not really apples to apples) where the foundation sub had sub'd out the rebar fabrication. Because of the drawing review, it was discovered the rebar fabricator had misread the drawings and had the rebar in interference with the anchor bolts. Unfortunately, the rebar had already been fabricated, so the sub had to eat the cost for new rebar, but I say this only because in this situation, there was great value in review the rebar shop drawings.

RE: Contractor will not provide rebar shop drawings?

Heaviside1925, the rebar shop reviews I see would not detect a clash as described. One of our guys is doing field reviews on behalf of the EOR for a project. This project is $600mil or so and there are multiple floors of slabs. There are full rebar shops, and IFC dwgs on site. The level of EOR review of the rebar shop dwgs is size and quantity. To do clash detection would take endless amounts of time, and nobody wants to pay us to review 100's and 100's of sheets of drawings to that level let alone coordinate them with another set of trade dwgs.

I did not think you might not do field reviews. If a project requires a permit in my area of Canada, the EOR must complete field reviews to get an occupancy permit.

RE: Contractor will not provide rebar shop drawings?

2
We never certify anything.

Our signature and seal on our plans only certifies that we did the design. It doesn't imply a warranty or certification that the plans are 100% correct.
Read any US state engineering act to see.

RE: Contractor will not provide rebar shop drawings?

Yea, I thought that waa a strange note to have on a drawing. Seems a bit weasel-ly and, at the same time, probably not something their insurance company wants to see.

RE: Contractor will not provide rebar shop drawings?

JAE, I was just typing the same thing.

Everyone else- please be careful about the word Certify. It is a word that is casually mentioned- but has significant implications.
As engineers, we should not be certifying construction

RE: Contractor will not provide rebar shop drawings?

I was prepared to argue with JAE based on what we do here in Wisconsin, but...

We sign a "Compliance Statement" when construction is complete. We do not certify.

DaveAtkins

RE: Contractor will not provide rebar shop drawings?

Brad805 Fully agree with your points and yes, we do field reviews. This may have been a one-off case, and I was not speaking as general rule, just a case I was involved with that the rebar drawing review saved a lot of headaches down the road. There are a lot more details and nuances I left out to not too be windy, but I thought I'd throw it out in case OP found any relevance in it. Just to clarify a point, the review did not detect the interference, the review detected that the rebar fab shop did not read (geometry and orientation) the drawings correctly. The result, if installed would have been an interference. The EOR (SE) was going to be on vacation and asked me to review them when they came through. It was my one little gold star playing in your sandbox for a day. Maybe completely irrelevant and if so, please ignore.

RE: Contractor will not provide rebar shop drawings?

I haven't read all the replies, and this isn't the world's largest project.

However,

Your dyamite, here, should you chose to do it, is to inform the local building department that you have not received rebar shop drawings, have not reviewed them, and are hereby withdrawing from the project. You can copy the contractor and the architect. Close it out and send a "cancellation fee" to whoever you have a contract with. This should result in a red tag and a ground stop on the project whereby the contractor can produce the shop drawings while the project is at a full, dead, halt. This is the nuclear option, but if you believe health, welfare, and life-safety are at risk as the concrete rebar placement hinges on it being done correctly, well, what choice do you have.

RE: Contractor will not provide rebar shop drawings?

"if shop drawings are not provided then our firm is not responsible for the structural certification and design of the project."

This is a BAD note because it gives the contractor tacit permission to NOT provide shop drawings, even if doing so ignores the consequences down the road.

A better approach would be to require rebar shop drawings, period. You could add weight to this requirement by stating that rebar shop drawings and review of same by the EOR are required as part of submitting the EOR's Compliance Statement (or whatever you must provide) to the Building Department and ultimately for occupancy.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

RE: Contractor will not provide rebar shop drawings?

Quote (lexpatrie)

Your dyamite, here, should you chose to do it, is to inform the local building department that you have not received rebar shop drawings, have not reviewed them, and are hereby withdrawing from the project. You can copy the contractor and the architect. Close it out and send a "cancellation fee" to whoever you have a contract with. This should result in a red tag and a ground stop on the project whereby the contractor can produce the shop drawings while the project is at a full, dead, halt. This is the nuclear option, but if you believe health, welfare, and life-safety are at risk as the concrete rebar placement hinges on it being done correctly, well, what choice do you have.

Seems a bit extreme for what appears to be a simple project.
Does not seem like a great business practice if you want further work in the community.
"Yeah, XYZ Engineering f'ed up my job because they wanted rebar shops for (2)#4 w/ 18" laps. What a bunch of idiots"

RE: Contractor will not provide rebar shop drawings?

Man, you guys do stuff weirdly!
We would never do rebar shop drawings - the closest we would ever come is reviewing drawings for precast concrete panels
But never for random rebar
We would always do a site inspection to check the reinforcement prior to pouring though
This is far far far more important than looking at some drawings anyway - anyone who has ever set foot on a building site knows that it's irrelevant what the drawings say, the important is thing is what they have built (and figuring out how many details they got wrong/basic non compliances they've done...)

RE: Contractor will not provide rebar shop drawings?

Quote (greenalleycat)

anyone who has ever set foot on a building site knows that it's irrelevant what the drawings say, the important is thing is what they have built

The reason we do it is so that if the rebar shop gets something wrong and ships out a ton of incorrectly bent, or incorrect size, whatever, steel then there are not huge delays while they tear all the bar out and have to re-fabricate, ship, and install everything again.

Rodbusters definitely look at the drawings, how else would they know what to build? And they're looking at the shop drawings generally and probably not the structural drawings. Whether it actually gets installed correctly is a different thing.

You review structural steel shop drawings though right? I don't really see much of a difference...

RE: Contractor will not provide rebar shop drawings?

I personally hate reviewing structural shop drawings (and precast), but yes, we do sometimes do that
Typically on larger jobs

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

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

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

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

RE: Contractor will not provide rebar shop drawings?

@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.

Quote (greenalleycat)

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.

RE: Contractor will not provide rebar shop drawings?

"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.

RE: Contractor will not provide rebar shop drawings?

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




RE: Contractor will not provide rebar shop drawings?

@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?

RE: Contractor will not provide rebar shop drawings?

So, they don't want to provide shop drawings because the project is so simple? My take on that is:
  1. 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.
  2. 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.
  3. 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.
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.

Quote (Greenalleycat)

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.

RE: Contractor will not provide rebar shop drawings?

@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...

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

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)


Quote (Greenalleycat)

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.

Quote (dold)

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.

RE: Contractor will not provide rebar shop drawings?

Quote (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"

Quote (Lexpatrie)

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.

Quote (Lexpatrie)

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.

RE: Contractor will not provide rebar shop drawings?

3
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.

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

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!

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

Quote (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.
Where are you located?

Quote (wth)

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.

RE: Contractor will not provide rebar shop drawings?

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

RE: Contractor will not provide rebar shop drawings?

Quote (human909)

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.

RE: Contractor will not provide rebar shop drawings?

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.

RE: Contractor will not provide rebar shop drawings?

I always think pretty hard about things that I require on my drawings because it gets really awkward when you relax the requirements later. If they're going to ask if they can omit, you allow the relaxation, and then something goes wrong it looks like you didn't meet your own standard of care. If you just didn't require it, then them making a mistake is on them. I generally try to give a justification for the relaxation or ask for something to mitigate it.

RE: Contractor will not provide rebar shop drawings?

Quote (Greenalleycat)

Man, you guys do stuff weirdly!
We would never do rebar shop drawings - the closest we would ever come is reviewing drawings for precast concrete panels

Where I work in Canada it is commonplace to get rebar shop drawings. Aside from very few simple projects where the contractor asks if they can use our foundation drawings as the shop drawings, we require rebar shop drawings to be detailed.

Quote (Brad805)

To do clash detection would take endless amounts of time

You mean you just place your anchors on the drawings willy nilly and don't check if they actually fit within the grade beam with the prescribed covers? How do you ensure that the rebar gets enough cover, or that the anchor has enough edge distance then if you don't check if it even fits properly?

Quote (TLHS)

I generally try to give a justification for the relaxation or ask for something to mitigate it.

This is the way.

RE: Contractor will not provide rebar shop drawings?

EngDM, no, that is not what I am saying. Those are basic design issues. I am suggesting the time to compare the rod buster shop dwgs with all the various trades takes a lot of effort. It is not what I see being done. One can have clashes with mechanical blockouts, electrical items, architectural details and any number of other things. Most have generic details for those. A set of rod buster drawings for a decent sized pour can be a 20-100 pages and they are designed to be concise for the field people. I do not see a lot of markups suggesting much of that is being checked.

RE: Contractor will not provide rebar shop drawings?

2
If anyone cares... from the point of view of a GC, not producing shop drawings and not having them reviewed is nuts.

Strongly agree with Eng16080/JAE/XR250/others regarding the overall purpose of shop drawing review - to ensure the details have been correctly interpreted by the GC, concrete sub, and bar fabricator.

I can't speak for every GC... but in my orbit, rebar shops are no different than any other submittal; an engineer's review does not absolve me of complete responsibility for conformance with drawings/specs/code/whatever. If an engineer misses a bend detail or whatever that's wrong, and we catch it in pre-pour, it's still my problem to fix. If it got missed by the EOR and installed, that means me and my guys missed it twice. It's on us.

Quote (Greenalleycat)

The process here is to produce structural drawings showing what is required,

No offense intended - but if you're telling me that you produce drawings sets for large, complicated projects which show every single possible configuration of many various concrete encapsulated assemblies in sufficient detail for rebar crews to order, tag, and tie bar using your drawings alone.. I don't believe you. Every single job I've ever build with significant concrete had SOME sort of clash, or issue with embedded utilities next to a column or thickened edge, or penetration not shown on structural, or whatever, that was caught at some point between rebar shop review and GC side trade coordination. That's why we do it, so it doesn't get caught on pre-pour when it's too late. Not to mention that I've never seen a structural drawing which had each individual bent bar identified with a piece code, which is an absolute necessity for a large complicated reinforcement design, and gets done as part of the process of producing the shops.

Quote (Greenalleycat)

Amazing that you guys are so trusting of your contractors

You're putting WAY more trust in your contractors by not requiring them to show you the plan before they start ordering bar. To me, and it seems to most of my colleagues in the states, that's crazy. They review shops specifically because they DON'T trust me to get it right. And I'm perfectly fine with that attitude because the stakes are high. I will never turn down one more opportunity to catch mistakes before the money has actually been spent.

Quote (Greenalleycat)

Why are you inspecting with the trucks lining up and why are you getting blamed if they fuck it up

No one is performing a pre-pour inspection day of, unless we're talking about a very small pour.

And if you are inspecting day of, in our world you've already looked at the shops so you have at least some idea how competent the GC is at all the required coordination.

RE: Contractor will not provide rebar shop drawings?

SwinnyGG nailed it.

RE: Contractor will not provide rebar shop drawings?

I have practiced as both an engineer and a contractor in both North America(NA) and Australia. The conditions Greenalletcat is talking about relate to the norm in AU/NZ where the engineer's construction documents near-fully detail the reinforcing steel such that shop drawings are not required for building structures.

The GC sends the EOR drawings to his rebar supplier, they schedule/cut/bend the rebar, and the steel fixers (aka rod busters in NA) install. The EOR does not get a rebar shop drawing to review.

The EOR in AU (used to) undertake his own rebar (pre-pour) inspections too. If it was a complicated arrangement it was common for them to occur over several days as the rebar was being installed (I am thinking of raft foundations, or complicated transfer floors).

For DOT bridge work (I worked on a large cable stayed bridge in AU) the engineer's drawings were of such detail that they included all rebar tags, bend schedules etc. Simply take it to the rebar supplies for scheduling/cutting/bending.

It has been more than 10 years since I have undertaken any AU work, so the standard of AU engineers drawings may have changed, but 'back in the day' I never saw - as an engineer on some projects, and contractor on others - any rebar shop drawings.

Now for NA projects - it would be an absolute disaster if the rebar supplier did not produce shop drawings, except for the most simple of projects. I just completed a minor project with small 16" square pedestals and had to product a rebar shop drawing.

So it is horses for courses...depends on the detail of the EOR's drawings and regional practices.

RE: Contractor will not provide rebar shop drawings?

Quote:

For DOT bridge work (I worked on a large cable stayed bridge in AU) the engineer's drawings were of such detail that they included all rebar tags, bend schedules etc. Simply take it to the rebar supplies for scheduling/cutting/bending.

As far as I can tell, our DOT doesn't require rebar shops. We provide a Bill of Reinforcement for each component (generally each piece that will be placed at one time) that includes coating requirements (epoxy coated or plain), bar lengths, the number required, bending diagrams, set diagrams for cut sets, total weights for the bars in each component, and a note that designates a prefix number for the groups of bars (Ensure fabricator prefixes Abutment no. 1 bars with numeral 1, etc.).

Laps not dictated by the bars lengths (i.e. where there's only 2 bars overlapped within a component) are called out in the details; first and last bars in sets are called out, etc. Everything needed for fabrication and placement of bars is in the plans.

RE: Contractor will not provide rebar shop drawings?

Quote (Ingenuity)

where the engineer's construction documents near-fully detail the reinforcing steel such that shop drawings are not required for building structures.

If that level of detail is in the CD's, then obviously it changes the conversation. That's a pretty big departure from how we normally operate.

I have a really hard time envisioning getting a set of CDs that are truly comprehensive to build from without any additional detailing at all in between; but if that's how they're doing it, they're obviously making it work.

RE: Contractor will not provide rebar shop drawings?

SwinnyGG, some countries are moving in that direction. Here is an example in Norway where no drawings were provided. Norway Bridge It will be a long time until North America goes that route, but some are trying.

RE: Contractor will not provide rebar shop drawings?

For regular buildings IFC should be sufficient for both manufacturing and placing of rebar. We model all the rebar in 3D in Revit, then we detail them in 2D and produce rebar schedules based on the 3D model, so all the info is in the model.

As mentioned earlier there are bridges and state run projects in Norway that has been built without paper drawings, not only without rebar drawings, but without any drawings. However, convincing the contractors to do it on design & build projects have been though, so usually we produce the plans, and provide the 3D reinforcement as a visualization tool.

IMO rebar drawings is the easiest part of a project to build from a model, as it's mostly repeating a detail along a line. And for complex details you can visualize it by filtering schedule numbers, rotating, mark with different colours among other tools.

That bridge linked on the other hand requires some serious modelling skills. Those post-stresssed anchors are probably modelled using dynamo (visual programming) or other tools specially made for that project. So they're basically pushing innovation, which is great in the long run, but probably limiting the number of firms capable of designing bridges in the short run.

RE: Contractor will not provide rebar shop drawings?

Quote (Brad805)

It will be a long time until North America goes that route, but some are trying.

They that will happen when the US adopts the metric system, and hell freezes over.

RE: Contractor will not provide rebar shop drawings?

Clearly regional differences are the biggest factor at play here

For us, the concrete standards setout the baseline for how steel is done
The contractor has responsibility to comply with those which prevents stuff being grossly wrong (in theory)
Next, all engineering drawings have standard notes and details at the front that replicate a lot of this and basic things like lap lengths etc
Then, typical concrete drawings will include elevations, sections, and plan drawings of the main foundation details so that critical information is conveyed

The complexity of these varies hugely according to the project of course
A house will have one foundation plan and 3-6 details usually
A commercial building will have many more, particularly if it's a concrete framed building
Typically every wall or frame would be elevated with critical information noted - rebar layouts, "don't lap here" and all that
Complex joints - such as a beam-column joint - are likely to be modelled in 3D with bar cranks etc shown - this depends on the job though as to how far this goes

So, not every single thing is detailed, but enough

RE: Contractor will not provide rebar shop drawings?

Ingenuity, that is very true. We have a very combative system for a number of reasons. I have attended some integrated project delivery seminars and that looked promising, but it is too difficult to award projects that way. I guess productivity improvements in construction may never change.



wth, the guy that started that bimcorner site offers a lot of training in the use of grasshopper with different software packages. I have been learning that and it is not that difficult. I can see a lot of benefits in this as you can drive your geometry, analysis and detailing with it. Structured Parametrics has created a number of tools as well. I am not affiliated with either of them.

RE: Contractor will not provide rebar shop drawings?

Maybe some examples would help to understand the differences between approaches.

I've attached a 3rd party UK example and found examples from the Philippines and Sierra Leone that look to have a similar approach including the bar schedule full reinforcement arrangements :

https://www.iom.int/sites/g/files/tmzbdl486/files/...

https://www.afdb.org/sites/default/files/corporate...


and a US set of drawings that omit the bar schedule and reinforcement arrangements beyond typical details

https://govtribe.com/file/government-file/p09-draw...



RE: Contractor will not provide rebar shop drawings?

Another contractor perspective (steel fabricator):

The quality of design drawings are declining in my area, leaving many areas of uncertainty. Schedules are getting more compressed, leaving less time for RFI's. We often rely on shop drawing review to clarify design questions that weren't answered via RFI. Another emerging trend is that consultants tend to use our shop drawings as a final check on their design. It is becoming more common that we're seeing markups on our shop drawings for changes to the design, unrelated to any uncertainties that we may have flagged.

I can't imagine doing this work without shop drawings. Its the final chance to say "did I understand you correctly" and "are you sure you want to do this".

RE: Contractor will not provide rebar shop drawings?

Ditto what CANPRO said for the steel side of things. I can barely RFI anything these days with the required drawing turnaround by the GC. So to make timelines we do most things in the shop drawings unless things are so uncertain that I cannot proceed without clarification. I bubble / make bold red what I need confirmation on to ensure the EOR cannot miss it.

When I was a concrete contractor shop drawings for reinforcing steel were the norm. However, I never liked them much as they mostly convoluted things and were pretty worthless since I worked in restoration where dimensions are never quite what they were supposed to be. I eventually changed from getting the rebar supplier to do the detailing / bar cutting to ordering stock lengths and cutting as required on-site. Circular ties or large stirrups or what have you I still had them produce a drawing and do the fabrication since those were hard to do properly. Once I switched to this approach engineers that I usually worked with would be fine without shop drawings and we field reviewed everything. Engineers I did not have a history with still required shop drawings which I produced in CAD for them.

As others have said seems to be local practice that dictates. As an engineer these days I wouldn't mind a small slab pour without shop drawings so long as I am doing the physical inspection.

RE: Contractor will not provide rebar shop drawings?

Here's a sample of our bridge details and bill of reinforcement. Our spec book and notes cover the rest. For bends and hooks, we reference the ACI Manual of Practice for Detailing Reinforced Concrete Structures.

RE: Contractor will not provide rebar shop drawings?

To discuss the drawing quality problem I think one would have to divide the discussion into regions, and market sector. The bridge world always is dealing with authorities that care far more about what they are supplied. Most seem to spend vast amount of time creating standard details they want suppliers or consultants to follow. As a result, I think the quality is better in that market. Now, I have not worked much in that field, but I have found endless examples of details from that sector when researching problems. In the AEC world, the quality is driven by owner's, architects and building officials. All of those vary wildly in what they expect.

The timeline problem we have now is odd. Some deal in reality, some never think things thru and simply ask for something unrealistic and hope for the best.

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