Do you like this detail and why or why not?

[TRAK.Structural]

I see this a lot in my area but have never understood why from a structural standpoint this is allowed without much thought. There is the argument that it has been done for years and years without issue, which is valid in a sense, but I would like to be able to rationalize the acceptance. Tell me why this works, or doesn't.

1. Net uplift seems like it could be an issue with this load path, would you prohibit the use of this in this case?
2. Is getting solid/full bearing of the plate on both the brick and CMU a concern with residential construction quality?
3. Shear load (in-plane) gets transferred to the plate at the outside edge by the sheathing and then has to get to the anchor bolt, seems less than ideal.
4. What about edge distance concerns for the anchor bolt in the plate?

 

[Tomfh]

no way

In that case I don’t like it since the top course can pull off. I see plenty of cracked horizontal mortar beds.

I’d want that anchor deep enough to mobilise the whole wall.

 

[Harbringer80]

This is always true for any detail. That’s why the sole plate washers need to be large enough to confine the outboard edge. This load path coupled with toenail-withdrawal through the end grain at stud bottoms is how uplift gets into the foundation.

One there is no plate washer on the detail. Also it's going to take a very thick plate washer to actually have any effect with that large of a cantilever. Are you planning on having a plate washer go under the 2x4 sill? Typically for thick walls (think 2x10) we are offsetting the sill bolts toward the sheathing side and using a normal plate washer rather than coming up with some enormous plate washer to get within 1/2" of the sheathing.

Two the load path for uplift would be wall sheathing edge nailing into the sill. I'm not considering toenails for uplift....

 

[bIockhead]

Great thread, thanks for posting!

Agree that it comes down to the loading, and that if this were to fail, we would expect that top course of block plus whatever brick clung to it would get ripped right off. Are all these buildings just not experiencing the design loads (true for many load types), or by the time you get that far down, there are enough different attached components balancing out that load?

As far as whether it's realistically cracked or not, Canadian code only lets you use masonry in tension in flexure calcs, and not to resist pure axial tension. Even in flexure, the code reduces ft to only 0.1 MPa specifically for cantilevers. Steel is needed for anything south of the origin on the interaction diagram.

The detail shown is a composite wall, and a relic of old design and construction. Many have held up great but putting in an air space and making that brick a tied veneer means that it would need to be analyzed as a 4" URM element. I would guess it fails once you apply any loads.

Only way it works is by disagreeing with the material standards or the building code imo