Attaching to existing masonry
Attaching to existing masonry
(OP)
I am designing an addition to an existing building. I have situation where I have to connect a deck angle to an existing CMU wall (this wall would be non bearing for the new structure). I have existing brick veneer on the existing wall that the architect does not want to remove. Can attach the deck angle to the existing wall using epoxy anchors or using thru bolts ? The existing CMU wall is fully grouted and I have to transfer about 4.5 k shear load over a length of 50'.






RE: Attaching to existing masonry
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
I would tell the architect that the veneer is not structural and you can't use it to transfer loads. Go back to the base cmu and do your attachment there.
RE: Attaching to existing masonry
RE: Attaching to existing masonry
Regardless - brick is pretty "lousy" - see if you can get to the grouted CMU - much better results!!!
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
Bo not bear on the veneer!!!!!!!!!!!!!!!!!!!!!!
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Attaching to existing masonry
RE: Attaching to existing masonry
The existing masonry wall is 22' tall with no openings. The new deck is going to be at 8' height.
RE: Attaching to existing masonry
Adhered veneer (noncomposite wythes) relies on the back up for out-of-plane loads only. Veneer bearing on the foundation wall is typically isolated from the back up structure vertically and laterally (in the plane of the veneer) and assumed to be self supporting for loads in the plane of the veneer. Given the small magnitudes of lateral loads, and no net tension on the veneer at the foundation level due to these additional lateral loads, the loads may be transferred via anchors in the veneer only and not through through-anchors to the CMU back-up.
RE: Attaching to existing masonry
The IRC in the U.S. prohibits this. I don't think the IBC out-and-out prohibits it, but it probably discourages it, and says it needs special engineering attention. The veneer can carry the vert. load, but needs shelf angles periodically in height. Remember, brick tends to grow in size while concrete or CMU's tend to shrink. The veneer can take some lateral load in plane. But, there should be no load perpendicular to the plane of the wall, or relative movement induced by the deck on the brick veneer wall. I would not attach a deck just to the brick veneer (to the veneer alone) because of the potential of lateral loads on the veneer.
RE: Attaching to existing masonry
RE: Attaching to existing masonry
RE: Attaching to existing masonry
Upon rereading, and I had already read it several times, you certainly might be right. The "4.5 k shear load over a length of 50'" reads better your way, than as a vert. load. I still might put that 90lbs./l.ft. into the plane of the wall if I had test prisms of some of that veneer brick/mortar lay-up; and had been able to design for it btwn. the veneer and the CMU wall. But, I think on existing brick veneer I would put that into the grouted CMU wall through some specially designed shear brackets. I do not want this loading to impart a load perpendicular to the plane of the veneer. This would involve removing 6-10 bricks at 6 or 7 locations and then partially replacing the brick around the brackets, with flashing, caulking, etc.
RE: Attaching to existing masonry