Bar Grating on Concrete Beams Detail
Bar Grating on Concrete Beams Detail
(OP)
See attached sketch. This is rooftop, within a screen but otherwise exterior. A series of flying beams forms a screen and various intermediate levels and at one of these levels there will be bar grating supporting mechanical equipment. A couple of beams will be steel to allow future removal/access but otherwise all concrete.
Any suggestions for a detail for the grating to concrete beam? Seems like it will require an embed of some type to which angles/clips can be welded?
When using embeds at exposed conditions what precautions are taken to limit water ingress around the plate into the beam?
(I'm stuck with the concrete beams - so going all steel isn't an option)
Any suggestions for a detail for the grating to concrete beam? Seems like it will require an embed of some type to which angles/clips can be welded?
When using embeds at exposed conditions what precautions are taken to limit water ingress around the plate into the beam?
(I'm stuck with the concrete beams - so going all steel isn't an option)






RE: Bar Grating on Concrete Beams Detail
Having small embedded anchors or studs that protrude from the beams is not a good idea. They are easily damaged, can be a safety concern, and often require the grating be precisely and carefully placed before it can be tied down. We started using the G-clip fasters at electric generating stations in the early 1990's - they have proven to be quite satisfactory.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Bar Grating on Concrete Beams Detail
Mike McCann, PE, SE (WA)
RE: Bar Grating on Concrete Beams Detail
RE: Bar Grating on Concrete Beams Detail
RE: Bar Grating on Concrete Beams Detail
RE: Bar Grating on Concrete Beams Detail
Here is some background info that may be of interest:
Embedded plates, anchored with Nelson studs, are used for all sorts of purposes at electric generating stations, including bar grating support. In our experience, as time goes by (measured in years) a disturbing percentage of the embedded plates come loose - then you have a "perfect storm" of trouble. Often the reason they came loose was honeycomb concrete directly below the embedded plate. No matter how diligent the Contractor, getting the concrete properly consolidated under the plate is an elusive goal - and you don't know there is a problem, the plate blocks view of the honeycomb. At this point, the (loose) Nelson studs make things worse - they insure that concrete BELOW the shallow honeycomb is disintegrating, too. Now, removing the compromised embedded plate, with Nelson studs attached, causes more damage. Finally, you have to try to come up with a way to replace the embedded plate, and all you have for support is concrete that has been more or less pulverized.
We found it best to avoid using embedded plates when possible - easily done with many bar grating supports.
Where you do have to use embedded plates, we doubled the number of Nelson studs and put numerous small holes in the plates to help get trapped air out during concrete placement.
www.SlideRuleEra.net
www.VacuumTubeEra.net