Simply supported steel lintel on masonry wall connection?

[Redacted]

Hi there,

I am running into a bit of an issue on a job site with some lintels.

I had originally designed simply supported reinforced concrete lintels, where the architect approved the depths, however, based on an email today it seems that the depths will need to be reduced to fit the door frames in.

Most of the lintels that I specified were 8” deep, and the spans are quite short at 4’.

The architect is asking whether we can use 4” or 6” deep steel beam sections for the lintels instead so that the door frames fit.

The issue is that these lintels are right up to the timber rafter wall plate (only supporting the roof).

The typical construction of these elements where I am from involves constructing a reinforced concrete lintel for openings (or bond beams with 2T12 bot as the top course for all interior and exterior masonry walls without openings) that is anchored into the timber wall plate (every 48” with a CIP anchor), and the rafters are connected to the wall plate either with skew nails or hurricane clips.

I am not sure how this system will work with the steel beam so any advice or sketches with options would be greatly appreciated.

My current thinking to get the steel beam system to work is to demolish the existing bond beam and create a notch or pocket cut out at the top of the masonry wall, which will allow the steel beam to have a bearing rest of 8”.

I have seen connection details of having a plate welded to the steel beam and using CIP anchors to secure it. I am thinking that as there is limited space this may be a difficult approach for the contractor.

I have also seen details of a steel beam just resting in the pocket on a concrete padstone and just filling the pocket in with concrete. This would perhaps be the easiest approach but would like to hear opinions on temperature expansion and if this will cause any issues with this approach.

What kind of detail would you use to connect the timber wall plate to the steel beam? I do live in an area with hurricane wind uplift. In our building code it states to have anchors at every 4’.

Sorry for the long question but any input would be appreciated.

I have attached a sketch and image of the site.

 

[JedClampett]

If you look at Powers Metals, they make lintels that you can build into the block. They even have load tables.
Just curious, why not just reinforced CMU lintels? I've designed hundreds of them and never had a problem or question.

 

[Redacted]

@JedClampett

Thanks for the insight, unfortunately where the job is located they don't have access to bespoke steel solutions and there is no time to order as the job will need to be finished this month. The only materials available are what we can source from the local steel supplier like I beams and angles.

It's the same reason why CMU lintels were not specced, the lintel blocks just aren't available, we only have the standard CMU block with two cells.

The depth requirement of 6" is what is causing the issue and I guess I can look into designing a 6" reinforced concrete lintel as well but I have never needed to design a beam less than 8" deep.

 

[WARose]

What kind of detail would you use to connect the timber wall plate to the steel beam? I do live in an area with hurricane wind uplift. In our building code it states to have anchors at every 4’.

Me personally, I'd weld nuts to the top of the beam (offset from the stud spacing), have a oversized hole in the top plate(s) to accommodate that nut, and finally, I'd have a threaded rod (w/nut) or bolt screwed into that nut that would hold the sill plate down.

That might help out at the ends if you have some kind of hold-down hardware that needs to anchor to something.

It's the same reason why CMU lintels were not specced, the lintel blocks just aren't available, we only have the standard CMU block with two cells.

The mason can cut out the cells? I've seen them make bond beams out of regular blocks.