Impact louver - Building Code

[kdxbob]

Hi - I'm an owners rep for a building construction project in a wind borne debris region - Fl coast. Issue of the day is whether our exterior louvers need to be impact rated.

Florida BUilding Code - 1609.1.4.5 (Protection of openings) Louvers protecting intake and exhaust ventilation ducts not assumed to be open that are located within 30 feet of grade shall meet requirements of the Large Missile Test.

Question #1 - What does "not assumed to be open" mean? I'm guessing this is related to wether the building is closed or (partially) open.

Question #2 One of our louvers is covering an exhaust fan outlet - no real "ventilation duct". Does that in any way make this an exception?

I've generally thought that all openings needed to be protected with something in a WBDR.

Thanks

 

[imok2]

Answerer to question #1

BUILDING, OPEN. A building having each wall at least 80
percent open. This condition is expressed for each wall by the equation:
Ao?0.8 Ag (Equation 16-31)
where:
Ao = Total area of openings in a wall that receives positive
external pressure, in square feet (m2).
Ag = The gross area of that wall in which Ao is identified, in square feet (m2).

for more see:1609.2 Definitions. The following words and terms shall, for
the purposes of Section 1609.6, have the meanings shown
herein.

http://www2.iccsafe.org/states/2004_florida_codes/2007_Revisions/2007_Amendments_FL_ Bldg.pdf

 

[DonPhillips]

I would call the building official and ask the question.


Don Phillips

http://worthingtonengineering.com