rebar shop drawings

[v2]

Hi,
This an interesting question that perplexed me lately.
Can a 2-story concrete house be built without rebar shop drawings?
the house is on 14" auger cast piles. Fisrt floor concrete slab is 6' above grade.
The second floor and roof are also 7" to 9" concrete slabs.
everything supported on load bearing reinforced CMU exterior walls and interior concrete columns...
Total house area is about 5000 SF, and it is about 35' high.
all concrete construction.
There are transfer beams and slabs due to elaborate architectural features.
The stairs are concrete as well. There are concrete balconies with 6" step down at the door sills.
So, it is clear the house is fairly complicated with a lot of rebars in it.
I looked up the Florida Building Code on this issue but could not find anything.
The project is in south Florida near the cost line in hurricane zone.
I appreciate your thoughts on this.
Regards,

V2

 

[wannabeSE]

I would expect to find the requirement for shop drawing in the contract documents (specifications).

 

[dik]

As wannabe notes, the requirement for shop drawings is often in the Contract. One consultant I worked with about 25 years ago prepared structural drawings that were in effect 'placing' drawings and these could be used as shop drawings. Shop drawings give you an added 'review' prior to placing steel.

Dik

 

[ron9876]

I don't think that there is a requirement in the Florida Building Code. However given the complexity of the house that you are describing and knowing the quality of the contractors that normally build houses in this market I would strongly recommend that shop drawings be required to be sure the contractor understands your drawings. Unfortunately they will build the house from the shop drawings.

 

[dik]

It may not be in the code (not in any codes that I'm aware of)... but, it may be in the construction contract (common item). In which case, the Contractor is obligated to provide them.

Dik

 

[v2]

Thank you for your replies. This issue actually came up during the permit phase.
The building official requested that the plans be detailed in such a way that shop drawings would not be necessary and not be required or needed! We have done many similar projects before and never had to deal with this issue in this fashion. Like everyone else we have in our project spec's detailed information instructing the contractor to submit rebar detailing in the form of shop drawing. But in this case the building official still not satisfied with this shop drawing specifications and requirements.
my concern is whether the building official is over reaching and being unrealistic.
our opinion is that the house is too complicated to detail and call out all of the rebars directly on the structural plans.


V2

 

[hokie66]

The building official is overreaching, but I don't know what you can do about it.

 

[dhengr]

That requirement by the BO sounds like absolute silliness, but there is no telling what authority some BO’s will bestow upon themselves these days. That shouldn’t be any of their business, as long as the job gets built to code, assuming they understand the intent of the code. I suppose you could detail the rebar, but is the BO going to compensate you for that time and effort, or make sure the owner does? Can he assure you the rebar will come in at a lower cost by a comparable amount? Then, who is going to check the shop drawing, his brother-in-law at an extra fee? Why don’t you just note on your drawings the need for six barrels of rebar bends of various sizes and shapes, some hooks, a truck load of extra splices; to be properly located by the BO and his dept. inspectors during their sight visits.

 

[wannabeSE]

I do not understand the building code officials request. Unless the concrete or CMU design is a deffered submittal, the structural drawings should suffice. The structural drawing should provide enough detail so the plans can be reviewed and the reinforcing inspected without shop drawings. I would be concerned if an inspector referenced shop drawings rather than the structural drawings while inspecting the reinforcement.

 

[hokie66]

Agree with wannabeSE on that. In Australia, shop drawings for reinforcement are almost never made. The bar setters work off the structural drawings and a whole bunch of bending lists. When I go to the field to check the reinforcement, I take a set of structural drawings, not shop drawings.

 

[TXStructural]

That is not a code requirement and the official does not really have the authority to require it. It may be a contractor or owner that wants that detail so the contractor can self perform, and had the official make the request. If it is the case that the contractor wants to bend his own bar without proper fabrication tools and details, don't allow it. Field bends like that are never bent to proper radius and short laps are very common.

Shop drawings serve two main purposes: 1) so that the bars can be properly fabricated (not on the bumper of the pickup) and 2) to assure that bars are identified properly and can be placed in the correct part of the building.

Rebar detailers are uniquely qualified to figure out how the bars can be fabricated for economy of material and placement. Very few engineers have the experience or time to properly detail bar. Rebar fabricators generally provide this service as part of the fabrication cost, and dislike cutting and bending on other people's shop drawings. It often results in field problems and inefficient use of stock bar lengths. They may charge a premium to fabricate from outside details, since they may have added waste, and difficult sizes and shapes.

One of our members reported to us that they had a building official requiring that the 100-plus foot bars in a grade beam, shown in drawings as "CONT", be continuous one piece without splices. They finally convinced him it was not really required.

 

[TXStructural]

Also, there is no single definition of shop drawings. In some regions, shops include only the cut and bend information, along with identification showing where on plan a certain bar number is to be placed (without tags/ID, many bars look alike). In other regions, shops will have significantly more details, enough to properly place bars, including cover and location, reinforcement supports, and relationship of bars to each other where needed.

ACI 301, ACI/CRSI 315, and a couple of CRSI committees are working the issue now.