Calculating Multi-Story Stairway Width Tracy Mikulec Tracy Mikulec, a seasoned leader in the digital marketing realm, currently serves as the Director of Digital at SixAxis, a pioneering manufacturer of industrial and commercial safety products from renowned brands like SafeRack, ErectaStep, and Upside. With a career spanning over three decades, Tracy has been at the forefront of digital innovation, ecommerce, and technology strategy. Since January 2015, Tracy has been instrumental in shaping the digital landscape at SixAxis, LLC, based in Andrews, South Carolina. His role involves leading digital strategies and overseeing technological advancements for SixAxis and its diverse portfolio of brands. May 07, 2019 Estimated reading time: 2 minutes If you haven’t read our IBC Stair Width Calculation article, I recommend reading that first so that you can see the IBC codes we reference. If you have already read it, below is a scenario in which we calculate the required width of multiple stairways that serve multiple floors. Scenario: We need exit stairs for a building that has 3 floors that have varying occupant loads. There is a sprinkler system, but the system was not installed per code requirements. The occupant loads are as follows: Floor 1: 40 occupantsFloor 2: 480 occupantsFloor 3: 110 occupants The required total stairway width per floor is as follows: Floor 1: 40 occupants x 0.3” = 12” (BUT the minimum stairway width for a floor serving less than 50 occupants is 36”. Can you imagine trying to walk down a 12” wide stairway?)Floor 2: 480 occupants x 0.3” = 144”Floor 3: 110 occupants x 0.3” = 33” (BUT the minimum stairway width for a floor serving more than 50 occupants is 44”.) What do we do when each floor requires a different width? We use the largest minimum width because we don’t want to create a bottleneck effect where a wide stairway leads into a narrower stairway. Therefore, we want to use the 144” measurement for the minimum combined stair width. We will need two stairways because we have an occupant load between 1 and 500 per story. The 144″ width can be divided between the two stairways. BUT in case a stairway is destroyed or inaccessible during an evacuation, the remaining stairway needs to be at least half of the required minimum (144″). We cannot have a stairway that is 60” wide and the other one is 84”. Why? If we lose the 84” stairway to a fire, we only have the 60” stairway which is less than half the required width. Summary: We calculate the minimum required combined width by multiplying the occupant load of each floor by 0.3″ and using the largest number, which is 144″. We need two stairways, so we can divide the 144″ between the two stairs. However, since we only have two stairways, each stairway must be at least half of the 144″. View IBC Stairways StairsTools & Resources IBC Stair Width Calculation Read More » May 6, 2019 StairsTools & Resources Types of Stairs for Commercial and Industrial Use Read More » June 7, 2022
Calculating Single-Story IBC Stairway Width Tracy Mikulec Tracy Mikulec, a seasoned leader in the digital marketing realm, currently serves as the Director of Digital at SixAxis, a pioneering manufacturer of industrial and commercial safety products from renowned brands like SafeRack, ErectaStep, and Upside. With a career spanning over three decades, Tracy has been at the forefront of digital innovation, ecommerce, and technology strategy. Since January 2015, Tracy has been instrumental in shaping the digital landscape at SixAxis, LLC, based in Andrews, South Carolina. His role involves leading digital strategies and overseeing technological advancements for SixAxis and its diverse portfolio of brands. May 07, 2019 Estimated reading time: 2 minutes If you haven’t read our IBC Stair Width Calculation article, I recommend reading that first so that you can see the IBC codes we reference. If you have already read it, below is a scenario in which we calculate the required width of a multiple stairways serving one floor. Scenario: We need exit stairs from the second story of a building. There is a sprinkler system, but the system was not installed per code requirements. The occupant loads are as follows: Floor 1: 175 occupantsFloor 2: 300 occupants The required total stairway width per floor is as follows: Floor 1: Not applicable because this floor is ground level.Floor 2: 300 occupants x 0.3” = 90” We will need two stairways because we have an occupant load between 1 and 500 per story. The 90″ width can be divided between the two stairways. BUT in case a stairway is destroyed or inaccessible during an evacuation, the remaining stairway needs to be at least half of the required minimum (144″). We cannot have a stairway that is 44” wide and the other one is 46”. Why? If we lose the 46” stairway to a fire, we only have the 44” stairway which is less than half the required width. Summary: We calculate the minimum required combined width by multiplying the occupant load of the floor by 0.3″, which is 90″. We need two stairways, so we can divide the 90″ between the two stairs. However, since we only have two stairways, each stairway must be at least half of the 90″. StairsTools & Resources IBC Stair Width Calculation Read More » May 6, 2019 StairsTools & Resources Types of Stairs for Commercial and Industrial Use Read More » June 7, 2022
