I think i have a problem. need help understanding ibc 706.8.

[ccollings]

I have a double fire wall separating an existing building and a new addition. there are multiple openings in the fire wall. None of the openings are over 156 square feet. we were flagged on the code review to show compliance with 706.8. I need help understanding what is being asked for by the aggregate width of openings. My read is that i have a problem. the total length of the fire wall wall is 108 feet. 25 percent of that is 27 feet. the width of all the openings adds up to 30 feet. the existing building and the new building are fully sprinkled. the existing building is construction type IB with 2 hour rated exterior walls. the new building is construction type IIB.

 

[e hilton]

Exception 2: not limited to 156 sf if both are sprinklered. Wonder if that could be applied to the total width.

 

[ccollings]

I always thought that the allowable openings percentage was based on area rather than width, the same as openings in exterior rated walls so i missed this when i did my code analysis. the space with the fire wall is a tall space so the area of the openings is about 10% of wall area but 28% of wall width.

 

[ICE]

706.8 Openings. Each opening through a fire wall shall be protected in accordance with Section 716 and shall not exceed 156 square feet (15 m2). The aggregate width of openings at any floor level shall not exceed 25 percent of the length of the wall.

Exceptions:
1. Openings are not permitted in party walls constructed in accordance with Section 706.1.1.
2. Openings shall not be limited to 156 square feet (15 m2) where both buildings are equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.