Loose Lintel for Large Brick Opening

[skired]

I'm designing a load bearing CMU building with a brick facade (8" cmu, 4" cavity, 4" brick) that has 12 foot window openings.

I would like to keep the brick support to loose lintels and use bond beam lintels for the CMU openings instead of going to wide flange beams with a plate at the bottom to pick up the brick.

IMI recently had a webinar where they mentioned using a built up section of an angle and channel to span the opening. This would be a loose lintel, bearing on the brick on both ends of the opening. I attached a screenshot of the table they posted.

They suggest using an angle with a 5" horizontal leg but my instinct is to want the vertical leg of the angle and channel as close to the brick as possible.

Has anyone used this detail before and have any words of advice? Any issues or other suggestions?

 

[dik]

Can you use a W beam, bearing on the CMU wall with a plate welded to the bottom flange to pick up the brick? A lot better for support and deflection.

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

-Dik

 

[skired]

Can you use a W beam, bearing on the CMU wall with a plate welded to the bottom flange to pick up the brick? A lot better for support and deflection.

I can, some of the reasons not to use steel:

1. moving the cmu wall vertical reinforcement further away from the openings to accommodate the beam and bearing plate

2. how to resolve the torsion on the beam from the eccentric brick load - unless you'd continue the plate past the opening and bear that on the brick?

3. all of the IMI (International Masonry Institute) webinars pushing using CMU bond beam lintels as more efficient and economical than steel

 

[dik]

Can you use the lateral masonry ties to reduce or eliminate the torsion, using the wall/opening reinforcing and the roof to accommodate the horizontal load component?

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

-Dik

 

[XR250]

What about using an L7x4x3/8"

 

[skired]

What about using an L7x4x3/8"

Do you treat brick angles as braced?

 

[phamENG]

For that span, I'd be looking to bolt the angle to the CMU.

 

[LittleInch]

Catnics?

https://catnic.com/products/lintels/lintel-product-selector

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[bones206]

Not sure those Catnic type lintels are available in USA, but this is a product I like for this application:

https://ferocorp.com/products/fast-thermal-brackets/.

 

[LittleInch]

Well you're missing out - someone should set up an import business for them...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dik]

The reason for the beam and plate welded to the bottom flange.

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

-Dik

 

[phamENG]

dik - I agree but 1) some jobs it's best not to introduce new materials or create situations where the trades have to work over/around each other and 2) the OP specifically identified the beam and plate solution and said they were looking for other ideas.

 

[dik]

concur... but a loose lintel with bearing plates W rather than an L.

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

-Dik

 

[bones206]

What does the built-up angle + channel detail look like? Does the channel live in the cavity space between the brick and backup structure?

 

[skired]

What does the built-up angle + channel detail look like? Does the channel live in the cavity space between the brick and backup structure?

Yes, exactly. Image here is a screenshot from the IMI Webinar

 

[skired]

For that span, I'd be looking to bolt the angle to the CMU.

Problem with that is getting my CMU bond beam to work. I'm approaching the limits of what I'm comfortable supporting with CMU and don't want to add additional load.

dik - I agree but 1) some jobs it's best not to introduce new materials or create situations where the trades have to work over/around each other and 2) the OP specifically identified the beam and plate solution and said they were looking for other ideas.

minimizing some of the trade coordination is something I'm trying to do. This is a really large building with more than 70 of these openings...

concur... but a loose lintel with bearing plates W rather than an L.

Dik, are you proposing having a W as a loose lintel and not within the CMU bearing wall?

 

[dik]

Bearing on the CMU wall with bearing plates cast into the wall to support the W. Unless you need the 16" U blocks for a lintel in the CMU and not for lateral design, it's likely less costly to use the W section to form your CMU lintel.

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

-Dik

 

[bones206]

With the built up channel option, it’s probably worth discussing with the architect to make sure it plays well with the flashing and any long term durability issues are minimized with good detailing. Structurally if it works, it works. But the durability is a question mark.