Steel lintels for CMU walls? 2

[strucbells]

What are the advantages of using steel lintels over door and window openings for masonry walled buildings? I see questions on here often about these.

I mainly do industrial and water/wastewater projects and we often design small to mid size 1 story reinforced CMU pump station/etc. buildings and we typically specify CMU lintels built up within the wall, even for decently large spans over 10'-16' wide roll up doors, we usually can get the depth we need to make it work, especially if arching action can be taken advantage of.

This seems simpler to coordinate and install.

Are there advantages on commercial buildings or for multistory projects or in other sectors that make steel lintels advantageous?

Thanks

 

[dik]

For small openings, less than about 6' or 8', HDG steel lintels are a real convenience. They are generally outside the thermal envelope and have little impact on this. They are fast and convenient and relatively inexpensive. Consider how you would support a brick veneer without the use of them.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[JLNJ]

I agree with dik if the OP is referring to veneer lintels.

For openings in structural CMU, I like the continuity that CMU lintels provide. You can run the jamb and head reinforcement right through. There is no doubt about load path. They don't rust and they are fire resistant.

Steel angles do have the advantage that they are easy to set (well, for short spans) and don't require any cure time to continue the wall up. I've done it both ways.

 

[strucbells]

I was thinking about structural (8" - 12" CMU block) walls, but yeah that makes sense when you have a brick veneer or even 4" CMU veneer wall to require a steel or precast lintel over openings.

Does anyone use steel lintels for 8" - 12" CMU structural walls as well? Seems like additional coordination and things that can go wrong than just having a lintel built directly into the structural masonry wall.

 

[phamENG]

Steel lintels in CMU walls that I'm accustomed to are usually W8x21 with a steel plate welded to the bottom flange. There's virtually no benefit. If it's an exterior wall, they need to be galvanized, ground down, welded, and painted at the welds. They can't be placed until the jambs are grouted with an embedded plate or directly bolted. For commercial applications, you likely need to encase them in cut face shells anyway.

I use them for retrofits and cutting new openings in existing CMU. New CMU I always do lintel blocks with rebar and grout. Precast is a good alternative if you want quick construction.

 

[XR250]

For new construction, I use pre-cast if the numbers workout and there is no veneer.

 

[dik]

For masonry high rise, in past, I've used 8" deep precast with (3#3 old) single leg stirrups at the end for shear with concrete grout between HC plands to act compositely for a 16" deep RC lintel... worked really well and very cost effective, and you had the required fire rating.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik