Jambs/Lintels

[slickdeals]

Folks,
I am wondering how you approach designing the framing around an opening in masonry construction. I live in hurricane country and getting masonry to work for 10' heights becomes difficult when the openings are big.

How do you assume the load distribution around the opening? Do you assume the glazing on the opening to have a two-way behavior and distribute the loads to the framing elements (namely the jamb/header beam) based on a yield line of sorts? Or do you use a tributary width to design the lintel/tie beam and then design the jamb/wind column for a point load from the lintel?

We are Virginia Tech
Go HOKIES

 

[DaveAtkins]

It depends. A smaller window or door will distribute wind load by two way action. But when an opening gets very wide or very tall, the framing of the window itself distributes wind load more by one way action.

DaveAtkins

 

[ash060]

How much of the jamb do you consider to be effective to resist the load from the opening?

I am also in hurricane country and masonry design gets a little ridiculous, so I will look at it every way possible to get a sensible design. The old south florida concrete tie beam/column method has preformed and I can't get the numbers to work for the unreinforced portion of the masonry, so being liberal with my analysis for reinforced masonry can not be too bad.

 

[slickdeals]

@ash060: What is the best way to communicate personally other than the forums. I would definitely want to discuss this in depth because it is something we deal with on every project we do in South Florida. I am in Miami.

We are Virginia Tech
Go HOKIES

 

[ron9876]

I am also in South Florida and I use the 2 way distribution sometimes. I think the load distributes to the members of the window/door system based on their layout and then to the masonry. Certainly hard to get masonry to work in a lot of conditions.

To me the tough question is as ash060 said how much masonry can you count on to resist the resulting loads. Maybe h/3 at the most seems about right to me unless that starts to look wrong. You get to a point where you have to put in either a masonry pilaster or a concrete column.

 

[JohnWylie]

Have you checked the Brick Industry Association website? They may have a technical article that may assist you in your design.

http://www.gobrick.com/

 

[ash060]

slickdeals - I think you may have a co-worker in your WPB office that can get you my email. He is a UF graduate.

 

[slickdeals]

I guess small world. Whose email do I ask my colleague? Is ash060 something he might recognize?

We are Virginia Tech
Go HOKIES

 

[ash060]

He will recognize it.

 

[CTSeng]

It seems like the walls just keep getting taller and the openings wider. Architects don't seem to understand that 8" masonry wasn't meant to span 14 to 16 feet tall in high wind regions. I very often end up putting concrete columns in the wall around these openings. Although I've had some success convincing architects to put in 8"x16" piers (perpendicular to the wall) at the jambs, the increased depth makes all the difference.