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StructuralEng, Consultant
Category: Structural Engineering
Satisfied Customers: 7264
Experience:  Structural Engineer
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I am looking into enlarging a 34" opening into a wider 72" double door a

Customer Question

I am looking into enlarging a 34" opening into a wider 72" double door and want to add an adequate lintel.
Wall is masonry, made of two layers of brick with Lime mortar (150 year-old wall).
There are two floors above, I calculated the total uniform load over the 72" opening to be about 10,000 to 12,000 pounds (about 5000 kg) for both brick layers.
I am looking to add two steel lintels (ideally an angle since it is easier to install, otherwise a channel) for each layer of brick. Would be 8 foot long total, with 6 foot span.
I am thinking of using a lintel 5 to 6 inches deep (high) and 3 to 3.5 inches wide (2 inches if a channel), with 5/16 to 3/8 thickness.
Is that a reasonable approach? Thanks for you help.
Submitted: 2 years ago.
Category: Structural Engineering
Expert:  StructuralEng replied 2 years ago.
Hello. I'll be happy to assist you. I will have some questions for you.
Customer: replied 2 years ago.
While I suspect this is an automatically generated answer, please let me know what the questions are.
I should add that the floor joists are not bearing on the wall to be opened, as they run parallel to it.
Expert:  StructuralEng replied 2 years ago.
It was not automatically generated.
What is the total height of the brick left above the lintel?
Customer: replied 2 years ago.
I estimate it to be about 22 feet at most, probably closer to 20 feet: 2 feet above the lintel before the next floor, then 9-10 feet for each of the remaining floors above. I can give a precise measure tomorrow if needed. I used 100-130pcf to calculate the uniform load of up to 12,000 lbs based on these 22 feet height over the lintel. I am curious if my reasoning was correct.
Customer: replied 2 years ago.
Also, FYI, current "lintel" is a brick arch.
Expert:  StructuralEng replied 2 years ago.
You need two angles 6x4x3/8 ASTM A36 (through-bolted) to limit the deflection to span/600 (a requirement of the masonry code).
Expert:  StructuralEng replied 2 years ago.
Do you have any other questions for me on this topic?
Expert:  StructuralEng replied 2 years ago.
If you could rate my answer, I would appreciate it.