'Wall stiffener' under lintels? 1

[Redacted]

Hi there, I have seen on quite a few different engineers and architects drawings where they call out for a 'wall stiffener' under lintels, which is essentially filled CMU block with 1T12 or 2T12 typically. See the screen shot of a note from a drawing below.

I am trying to understand the purpose of the rebar in this case. They do not ever show or call out footings to go with the filled CMU wall, so I am assuming that the CMU wall and rebar would essentially just be sitting on the floor slab. They can perhaps drill about 6" or so into the floor slab to place the rebar but this most likely won't be enough to develop it for any moments? I'm not sure where moments would be coming from either as I would assume that for lintels there would just be the vertical load.

So I guess my question is what would the purpose of the rebar be if it does not get fully developed into a footing to take moments? Should they be calling out for a footing even though the lintels are lightly loaded?

The local building code does call for CMU block to be fully grouted under lintels over 6' but doesn't mention anything about needing rebar?

 

[strucbells]

Isn't this just jamb steel for your door opening? We would normally thicken the slab locally to create a footing of sufficient depth to allow development of a hooked dowel lapped to the jamb steel. For windows, we usually have sufficient room to just run the trim bars 2' past the opening on all sides.

 

[Tomfh]

Presumably to toughen the wall end, which can otherwise be quite flimsy.

 

[masonrygeek]

As the other posters have mentioned its steel to help the wall span around the window. It's not really there to support the lintel. The reinforced masonry acts together as the bearing for the lintel. The note is too vague and could be confusing. It doesn't state whether the bars are to be oriented vertically or horizontally and how long they should be. I wouldn't include that requirement on my drawings or in my specs for those reasons. Here is document showing typical masonry reinforcing details:

https://www.masonryinfo.org/wp-content/uploads/2021/05/Structural-Details.pdf.

This might help show what's typical in US masonry construction.