Purpose of steel plate under WF CMU lintel

[enginerd123]

I know this question may be a little basic, but I fell I should ask it anyways. I have been curious as to the purpose of a steel plate welded to the bottom of a steel W section lintel. Will the grout in the bond beam above the lintel and the webs of the CMU not transfer the load into the steel beam.

 

[hokie66]

Probably, but you have to give the mason a wide enough platform on which to place the masonry. Filling in on each side of a W section is tedious.

 

[SteelPE]

I think the plate is to allow the mason to cover the beam with "soaps" (a 2" thick piece of masonry) so you don't see an ugly WF section in the final as built condition.

 

[RUS777]

Also could be so that it is easyer to set plates to required elevation rather than messing with the fw lintel. Plus sometimes lintls are welded to bearing plates.

 

[SteelPE]

Russ777

We avoid welding the lintels to the bearing plates...... every time we do we get a crack the forms diagonally from the center of the plate to the door opening. We switched to a bolted detail. We find that this detail has a little more relieve to allow for the deflection of the beam w/o cracking the block.

 

[enginerd123]

thank you everyone for your responses, especially warnings about faulty details. all additional information would be appreciated.

 

[RUS777]

@SteelPE

Very good point, but when I was working for a steel erector all I ever saw were welded lintels.

 

[SteelPE]

All I can tell you is what I have seen and what we do. Doesn't mean my detail is perfect.... or even will fully prevent cracking.

I do some work with a steel fabricator and made them switch to this detail. They didn't like it but they did. I haven't seen one crack yet since the switch. However, about 2 weeks ago I was on a job where the fabricator accidentally switched from a bolted connection to a welded connection and guess what....... there was a crack.

His excuse was that he thought is was for lintels only. In this instance the beam was supporting roof joists and spanned from wall to wall so he didn't think the connection required the same flexibility.