Wind Load on Fabric Wall-mounted Sign

[epr]

When you mount a fabric sign on a flat wall of a building, (anchored only along its edges using tension cables) how do you determine the wind load for its design, using ASCE 7-98? Simply applying the suction force (determined by the analytical procedure) for components and cladding seems like it is very conservative. Does anyone have another interpretation?

 

[akastud]

epr,

From what I understand, unless you have testing done on the particular component to show that the wind load is less (which is usually more expensive than providing structure to resist the forces), you must use the full wind load as required under ASCE 7-98.

 

[akastud]

I apologize for not providing this earlier, but see ASCE 7-98 Section 6.4.3

 

[epr]

Thank you akastud. I am aware of that section, but I was hoping that someone had some words of wisdom as to how to "interpret" it more loosely. Some previous codes at least allowed "open" factors if more than 50% open mesh. etc. It doesn't make sense that this has been completely removed.

 

[egc]

I am not sure what you are after. Is the "fabric" a mesh fabric with the "solid" graphics part of the sign only a fraction of the total sign area? Is this this a single application question or a "what is the analysis technique" question?

I just hang here (occasionally)

 

[epr]

to egc,
This is a general analysis question. The mesh could be open weave with a solid graphic, or screen printed on an open weave mesh.

 

[egc]

Then you need to look at all of Chapter 6 (particularly Tables 6-111 & 6-12 Pages 66 & 67).

I just hang here (occasionally)