Interior Exit Stairways And Ramps Enclosures Fire Resistance.

Interior Exit Stairways And Ramps Enclosures.

Interior Exit Stairways And Ramps Enclosures . must be constructed as fire barriers according to Section 707 of the IBC, or as horizontal assemblies according to Section 711 IBC , or both.

Fire-Resistance Rating of Enclosures for interior exit stairways and ramps

1. Not less than 2 hours if connecting four stories or more.
2. Not less than 1 hour if connecting less than four stories.

Termination. 

Interior exit stairways and ramps shall terminate at an exit discharge or a public way.

Note:

1. The number of stories includes any basements but excludes mezzanines. The fire-resistance rating of the interior exit stairways and ramps should not be less than the floor assembly being penetrated, but it doesn't need to exceed 2 hours.
2. If a stairway or ramp does extend below the level of exit discharge, it must be equipped with an approved barrier at the exit discharge level. This barrier serves to prevent people from inadvertently continuing their descent into lower levels of the building.

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IBC & SBC : Fire wall protection in Stepped buildings

Fire wall protection in Stepped buildings

1. Stepped buildings: This refers to buildings with different roof levels separated by a fire wall.

2- Termination of Fire Wall: If a fire wall also acts as an exterior wall for a building and separates buildings with different roof levels, it must terminate at least 30 inches (762 mm) above the lower roof level.

3. Fire resistance rating: the exterior wall for a height of 4.5 m above the lower roof is not less than 1-hour fire-resistance-rated construction from both sides with openings protected by fire assemblies having a fire protection rating of not less than ¾ hour.

4. Exception: There's an exception to the termination height requirement. If the fire wall terminates at the underside of the roof sheathing, deck, or slab of the lower roof, certain conditions must be met:

1. The lower roof assembly within 3.0 meters of the wall must have a fire-resistance rating of at least one hour.
2.  The supporting elements (such as beams or columns) for the rated roof assembly must have a fire-resistance rating of at least one hour for their entire length and span.
3. Openings in the lower roof must not be located within 3 meters of the fire wall.

These regulations aim to ensure that in buildings with different roof levels, fire containment and resistance are maintained adequately to prevent the spread of fire between sections or buildings.