Garage Doors - Weighted Average of Int. & End Zones

[Raspo]

The Door & Access Systems Manufacturers Association (DASMA) utilizes a weighted average of the interior and end zone pressures in order to determine the wind loads acting on garage doors.

I have also heard the argument that if any part of the door is in the end zone the entire door needs to resist that pressure. Your thoughts?

Also, any guidance with respect to analyzing a garage door that protrudes 20ft from the face of a 2 story structure as a single story structure with respect to wind loading? It's hard to believe that the pressure on the 2 story structure would apply.

 

[csd72]

The wind doesnt know if it is a garage door or a wall. The pressures should be taken as the actual block pressures as if applied over a simple span.

 

[Raspo]

Perhaps I wasnt clear enough about what I am asking. Manufactures of garage doors have series of garage doors that cover particular ranges of pressures.

In analyzing the loads that the garage door will experience (in order to understand what door to specify/purchase), some engineers take a weighted average of interior and end zones based on the percentage of door area in each of these zones.

Other engineers simply take the endzone pressure if the door is located even 12 inches into the endzone and apply it to the entire door as the pressure that needs to be met by the door manufacturer.

While this is a simplified and conservative alternative, it can have a unfavorable cost increase. Just checking to see what method other engineers are typically using...

 

[csd72]

Thr roof joist manufacturer wont design for wind based on the worst pressure so neither should the wind pressure on the door be that way.

What I mean was, apply the actual moment from the stepped wind load distribution to wl^2/8 to get an equivalent uniform wind load(averaging is only conservative up to about 1/3 span or so of the higher pressure).

csd