I suspect that pretty much all of the people involved in steel framed structures that utilize metal deck and shear studs will be able to relate to the information contained in this post.
What has happened to the days when a design engineer gave specific instructions to follow for their design that did not leave room for interpretation or misinterpretation of what is required?
How often have you looked at a set of structural drawings and not found a definitive shear stud length – or even quantity?
Have you ever seen notes or details indicating that the stud length is to be a minimum of 1-1/2” over the top of the deck and minimum – or maximum – of 1” below the top of concrete?
Have you ever seen notes that tell you to place studs 12” in center on any beam or girder that does not indicate a stud quantity? How about a note that says that you are to place studs at a minimum of 12” on center regardless of the quantity shown for that member?
An estimator may have a different interpretation of such a detail or statement than a detailer or an installer or an inspector and none may be what the designer intended.
Many deck suppliers, if they are tasked with detailing the shear studs (they will usually tell you that since they are not supplying the studs, they will give you stud drawings as a “courtesy” and will take no responsibility for their correctness. How often have you seen deck suppliers shop drawings that give exactly what the design drawings give – sometimes with no definition of stud length, and sometimes with notes referencing the 12” on center “rule”? If they show a quantity where there was a note on the structural drawings referencing the 12” on center rule, did they calculate correctly? How many studs should be on a beam in a 30 foot bay? Does it depend on the column size? How far off the column flange do you place the first and last stud and was that taken into consideration when deciding on a stud quantity?
Have you ever run into a raised beam or depressed slab condition that requires a different stud length, but these are not clearly indicated on the shear stud shop drawings? It does not sound like a big deal, except that you now need to get different stud lengths – and the trades that follow may be delayed – and we know what grief that causes.
Often we see 7/8” and 1” studs shown on concrete encased beams and columns. This is easy enough to do for new steel in a fabrication shop where the pieces can be laid flat and the studs “machine shot”. We, however, have seen these studs detailed on “existing members” in renovation projects (at least in the New York City Metropolitan Area). This can be a nightmare as they may need to be hand welded!
Studs or deformed bars that are attached to the face of angles or bent plates that tie the piece into the slab are rarely shown on the stud shop drawings – at least those produced by the deck suppliers. If these pieces are shop attached to the beams or girders, the studs can often not be shop installed as they are prohibited by OSHA regulations because they create a tripping hazard. These items can easily be overlooked by the stud crew if the proper shop drawings are not presented to them. Again, not a major problem – just a need for a bit more time to get the material and install it while the trades that follow wait for the area to be turned over to them.
One of the many services that we, as A C Associates can provide, is to assist you in looking after these easily overlooked things. Not caught ahead of time, these things can be quite expensive to rectify and can cause a lot of friction with your customer.
Please feel free to call us before (preferably), during, or after you find yourself involved with any of these issues