Calculating Fire Stair Width and Stair load

[liarchitect]

Question i am in the process of designing the stairs for an a-3 house of worship

Due to a strange site, the sanctuary is elevated to the upper level

I have 3 exit stair serving that space. The occupant load for the entire space is 450 people. Does the code allow for me to split the occupant load to 150 people per stair, or do i need to calculate 450 people for each stair.

This question arises when trying to calculate the required stair width

thank you in advance, to this members of this great forum

 

[Coug Dad]

Each stair would accomodate at least 150 persons. A typical 4 foot stair accomodates at lease 160 persons (depending upon the code you are using).

 

[Brookhaven 58]

I do believe you would also have to consider section '1024.3 Assembly other exits'. At least one stairway (Main Exit) would have to handle one half of the occupancy load on that level or in this case 225 persons

 

[Coug Dad]

Good point Brookhaven if the space is configured with a main entry / exit

 

[Examiner]

Assembly does not get the factor or egress width in Chapter 10's Table 1005.1. You must use Section 1025.6 (2006 IBC).

 

[liarchitect]

thank you for the help

thank you for all your help