Loose Lintel Angle Design 1

[bolt45]

Does anybody have a good reference for loose lintel angle design? The problem seems to be pretty complicated in reality.

Can you assume the angle is braced by the brick? Has anyone simplified it and produced span tables?

 

[shobroco]

The Ontario Building Code has very limited tables, and CSA CAN3-S304 has more extensive ones.

 

[bridgebuster]

Free dowload on lintels from the brick industry

http://www.gobrick.com/Portals/25/docs/Technical Notes/TN31B 7.18.12.pdf

Index of publications:

http://www.gobrick.com/TechnicalNotes/LinkstoTechnicalNotes/tabid/11294/Default.aspx

It's not a difficult design.

 

[haynewp]

The BIA tables assume lateral bracing and it references you out to the AISC when not laterally braced.

Loose Angle Lintels. Loose angle lintels are used in
brick veneer and cavity wall constructions where the lintel
is laid in the wall and spans the opening. This type of lintel
has no lateral support. Figure 1a shows this condition.

 

[RFreund]

Depending on how thorough you would like to be, this manual is very helpful. It has spreadsheets I believe. However it is not free

http://www.lulu.com/shop/whitney-mcnulty/single-angle-design-manual/paperback/product-6241104.html

EIT

http://www.HowToEngineer.com

 

[MisterBill]

Equal leg angles are scaled up by a factor of 1.56 for deflection provided you are using the Ixx

They should be designed for the full height of brick above. Deflection will govern L/480 (see s304.1 masonry code Canada). Even if you have a control joint on one side only arching is ineffective. Rarely do I see control joints specified on the architectural drawing at design stage.

Taking 480x1.56=748. Design for L/748. Loose angles should not be designed for over 10'-0" spans. I would connect the angle back to the main lintel with batten plates or provide hangers to beam above (with a knee brace in ceiling space).

 

[Hokie93]

I have found the paper "Safe Load of Laterally Unsupported Angles", published in the AISC Engineering Journal, first quarter, 1984, to be useful. The paper provides load tables for yield strengths equal to 36 ksi and 52 ksi (yes, 52 ksi). The paper is based on research performed in Australia and Australian standards. The Editor's Note to the paper cites the following rule of thumb: "... use an allowable bending stress, F[sub]b[/sub] = 0.60F[sub]y[/sub], with appropriate serviceability deflection limits. Available evidence indicates that laterally unsupported practical angle sections in bending experience excessive deflections prior to any lateral buckling and, therefore, will be governed by deflection limitations rather than buckling".

 

[dik]

I typically design loose lintels for a triangular loading with the vertex along the C/L of the span if the is no control joint or with the vertex at the end of the span if there is a control joint... I typically use L/720 for deflection as an arbitrary value... I don't think I've ever designed one for the full height of a veneer wall...

Dik