Brick Shelf Angles
Brick Shelf Angles
(OP)
I'm posting this question for a friend, who writes:
We are working on a 60-feet high building, 4 levels with brick veneer/steel stud wall.
The BIA technical notes recommends shelf angles above 30-feet building height, unless the wall is rationally designed.
We are pursuing literature research to eliminate the need for the shelf angles. One reason is that the building structural steel is mostly fabricated.
We are considering several additional vertical control joints in the brick, particularly at the building corners and on each side of the windows. We have flexible ties to allow vertical brick movement. We are trying not to restrain brick as it grows.
Does anyone have any recommendations or suggestions for available literature that would tend to justify eliminating the shelf angles at each level?
We are working on a 60-feet high building, 4 levels with brick veneer/steel stud wall.
The BIA technical notes recommends shelf angles above 30-feet building height, unless the wall is rationally designed.
We are pursuing literature research to eliminate the need for the shelf angles. One reason is that the building structural steel is mostly fabricated.
We are considering several additional vertical control joints in the brick, particularly at the building corners and on each side of the windows. We have flexible ties to allow vertical brick movement. We are trying not to restrain brick as it grows.
Does anyone have any recommendations or suggestions for available literature that would tend to justify eliminating the shelf angles at each level?






RE: Brick Shelf Angles
RE: Brick Shelf Angles
Brick has long term irreversible expansion, while the steel structure does not. The angle are not just for brick support, but to separate the panels from each other so any movement can be allowed.
In the real world, the stiffness of the veneer may even be greater than that of the backup, so make sure the ties are proper to make things work together horizontally.
Once you get above the 40' mark, you are on thin ice. I have seen 20 story buildings properly designed that had excessive differences in elevation between the structure and the veneer, making windows a very big problem.
The BIA has seen many situation since brick veneer began to be used with a flexible back-up that can be subject to corrosion despite all the galvanizing and screw requirements. They are well experienced in the proper use of brick.
It is not just a structural situation, but you could be dragged into a future problem if someone allows a violation of a national recommendations.
Dick
RE: Brick Shelf Angles
Somewhere I have an article that estimates the growth per floor. On buildings with low floor to floor heights, shelf angles on alternate floors have worked!
RE: Brick Shelf Angles
RE: Brick Shelf Angles
Tide, R.H.R and N.V. Krogstad, 1993, "Economical Design of Shelf Angles," Proceedings of the Symposium on Masonry: Design and Construction, Problems and Repair, STP 1180, American Society for Testing and Materials, Philadelphia, PA.
RE: Brick Shelf Angles
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Grimm and Yura, "Shelf Angles for Masonry Veneer", Journal of Structural Engineering, Vol. 115, No. 3, March 1989.
Parker, "Façade Attachments to Steel Framed Buildings", AISC Steel Design Guide 22, AISC, 2008.
Technical Notes on Brick Construction, Brick Industry Association, www.gobrick.com.
18 - Volume Changes - Analysis and Effects of Movement, October 2006
18A - Volume Changes - Accommodating Expansion of Brickwork, October 2006
Tide and Krogstad, "Economical Design of Shelf Angles", ASTM STP 1180, ASTM International, 1993.
MSJC Code (TMS 402-08/ACI 530-8/ASCE 5-8) Building Code Requirements for Masonry Structures, The Masonry Society, Boulder CO.
RE: Brick Shelf Angles
RE: Brick Shelf Angles
It has maximum shelf angle spacings depending upon the wall type (wood stud vs. steel stud). The most you can get out of a steel stud wall is 30ft (38ft at a gabled end). After that you need to provide shelf angles at every floor.