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.
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.
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.
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.
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.
I live in SC …my home will be 10 years old in December I have pretty much the exact problem and now my roof is leaking. Everyone I have talked to “contractors” to fix it just say take the brick down. Mr. Randy can I send you pictures of my home or do you happen to know someone near me to help in SC.
