simplified wind design in ASCE 7-05 for bldgs with parapets?

[bjcure]

See ASCE 7-05 section 6.4.1.1, note #7.

This says that the simplified method for wind design can be used for buildings with either a flat roof or gable roof. Does this mean that flat roof buildings with parapets can be analyzed using the simplified method?

Some city reviewers are saying that method 2 (analytical procedure) must be used for all buildings with parapets, and I'm not sure if that was the intent of the code.

 

[msquared48]

I think that you are going to have a real hard time finding a flat roof building with absolutely no parapets. Technically, anything extending afove the line of the roof is a parapet, regardless how small.

Mike McCann
McCann Engineering

 

[bjcure]

I agree. I don't think I've ever seen a flat roof building without a parapet. That's what's confusing about the code- it seems to be saying that the simplified method can be used, but I've had some city reviewers disagree, and the code isn't clear enough to argue with them.

 

[csd72]

Rather than doing a whole new set of calcs, you may be able to do a comparison of parapet and no parapet to the detailed method just to show that it makes negligible difference.