Sliding Brick Veneer

[Randy L. Mayo, PE]

Called out to do an engineering evaluation on a 9 year old house with large cracks in the brick veneer over the garage. The cracked area was supported by a 4x4 attached to the wall studs that was flashed with a factory painted aluminum flashing. The 4x4 was strong enough to hold the vertical load but the bond between the mortar was probably compromised due to shrinkage of the studs and the 4x4 over time. There were no lugs or angle iron clips attached to the 4x4 and the brick slid down creating the cracks seen by the owner and the bulge in the back wall. I am bringing this to your attention as an item to check on your inspections.

[Marcel R. Cyr]

Obviously constructed wrong as usual Randy, and doesn't surprise me.

The angle must be able to support the brick veneer with a total deflection limited to the lesser of 1/600 of the span of the angle or 3/10 inch.

The angle rotation should be limited to 1/16 inch. When this approach is taken, there should be a minimum 1/4-inch separation between the bottom of the angle and the roof construction for the single story attachment.
The horizontal component friction force between the shelf angle and the brick veneer must be checked to make sure that the brick will not slide down the slope of the roof of the single-story attachment.
The maximum slope should be 14 degrees from horizontal, which is roughly a 3-inch rise for a 12-inch run.
The resistance to sliding can be achieved by welding 2-inch-long studs with at least 1/2-inch outside diameter to the bottom leg of the angle. These studs would project into the brick cores.
The other method around this for wood frame building would be step angle supports.

In either case, the example you have given here is a clear example of improper construction design or construction building performance.

Good picture for this example.

[Bob Elliott]

If you come up with one of your famous links to an illustration of proper support Marcel (that would be great)

Nice photo shop Randy The transparency illustration was nice.

[Randy L. Mayo, PE]

Bob

Here is a detail I found and two figures from the IRC code book.

I disagree with the code book on the need for the angle clips for roof pitches over 7:12

By my calculations the coefficient of friction between the brick mortar and the steel angle is about 0.45 and divide that by two to get a safety factor of 2 puts the maximum roof pitch at about 3:12 with out angle clips.

[Marcel R. Cyr]

I agree Randy. I don't go along with that 7/12.
Thanks for the graphics, I could not find one, but know what it is supposed to look like and how it is done.
I am more used to the commercial details where steps are created on a main support angle fastened to the structural frame of a building.

Code does allow brick to be installed on wood support frames as long as it is engineered for it.
Stops are required for slopes to prevent that slippage affect.

Thanks

[Bob Elliott]

Originally Posted by mcyr

I agree Randy. I don't go along with that 7/12.
Thanks for the graphics, I could not find one, but know what it is supposed to look like and how it is done.
I am more used to the commercial details where steps are created on a main support angle fastened to the structural frame of a building.

Code does allow brick to be installed on wood support frames as long as it is engineered for it.
Stops are required for slopes to prevent that slippage affect.

Thanks

I have not seen that first illustration before and saved it to my files.
Thanks Marcel.

[ROBERT V. YOUNG]

Originally Posted by mcyr

Obviously constructed wrong as usual Randy, and doesn't surprise me.

The angle must be able to support the brick veneer with a total deflection limited to the lesser of 1/600 of the span of the angle or 3/10 inch.

The angle rotation should be limited to 1/16 inch. When this approach is taken, there should be a minimum 1/4-inch separation between the bottom of the angle and the roof construction for the single story attachment.
The horizontal component friction force between the shelf angle and the brick veneer must be checked to make sure that the brick will not slide down the slope of the roof of the single-story attachment.
The maximum slope should be 14 degrees from horizontal, which is roughly a 3-inch rise for a 12-inch run.
The resistance to sliding can be achieved by welding 2-inch-long studs with at least 1/2-inch outside diameter to the bottom leg of the angle. These studs would project into the brick cores.
The other method around this for wood frame building would be step angle supports.

In either case, the example you have given here is a clear example of improper construction design or construction building performance.

Good picture for this example.

Thank you Mr Cyr for the deflection limits.
Its is copied and saved as we speak''so to speak''ha ha.
Thanks a feather in my cap.Thanks for the feather.

[mthomas2]

Thanks to everyone who contributed to this thread, that detail was new to me.

[David C. Macy]

Thanks for the post and education, illustrations.

Maybe we can ask Dominic to add transparency to the HIP program

[Bob Elliott]

Originally Posted by dmacy

Thanks for the post and education, illustrations.

Maybe we can ask Dominic to add transparency to the HIP program

Nah! you can do that on any graphics software.
His list is long enough right now.