Brick Shelf Angle 1

[mzaitz]

All,
This is a variation of all the shelf angle posts in the archive. I have a 3 story building that has precast veneer up to 3 ft or so above the second floor and then brick for 24 ft. The construction for the building is composite steel for the 2 floor and lt ga truss roof. My original thought was to put a shelf angle at the third floor but I am rethinking that. My understanding is that the shelf angles are used due to the expansive nature of the brick when it absorbs moisture. ACI530 allows 30 ft from foundation to the top of the brick at the eave. Has anyone done something like this without the shelf angle? Any other thoughts? I may just put in the shelf angle since ACI 530 clearly mentions the height from the foundation but that means designing the 3rd floor beams for a stricter deflection limit.

MZ

 

[KootK]

I think that this would be okay. The only time that I've ever had trouble was when the base building structure was framed in wood. When the brick swells and the wood shrinks, you can get issues at doors, windows, and plumbing.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.

 

[Ron]

A shelf angle helps more than just the simple movement of brick. I would use it to separate the different constructions (precast and brick), providing a "soft" joint between to allow for differential movement.

 

[XR250]

@Ron
Seems like a waste supporting 24 ft. of veneer over 3' of pre-cast.
Are you thinking the brick will expand horizontally more than the pre-cast and cause cracking? Wouldn't the same thing happen when it is supported by a lintel as the lintel will not expand at horizontally the same rate as the brick?