Loading...
2019-02-20_Stair Tower Fire Rating CorrespondanceJune 12, 2018, 11:11 AM Good Morning Louis, I have been trying to determine if both the stair tower to the corner house and the adjacent duplex on Bridge Street require a (1) hour fire rating on the wall assembly or if it is only required at (1) of these buildings. What is your interpretation of this item per the code? IBC 2009 Chapter 7 Fire and Smoke Protection Features Section 705 Exterior Walls 705.3 Buildings on the same lot For the purposes of determining the required wall and opening protection and roof-covering requirements, buildings on the same lot shall be assumed to have an imaginary lines between them. Where a new building is to be erected on the same lot as an existing building, the location of the assumed imaginary line with relation to the existing building shall be such that the exterior wall and opening protection of the existing building meet the criteria as set forth in Sections 705.5 and 705.8. Exception: Two or more buildings on the same lot shall either be regulated as separate buildings or shall be considered as portions of one building if the aggregate area of such buildings is within the limits specified in Chapter 5 for a single building. Where the buildings contain different occupancy groups or are of different types of construction, the area shall be that allowed for the most restrictive occupancy of construction. 705.5 Fire-Resistance Ratings: Exterior walls shall be fire-resistance rated in accordance w/ tables 601 & 602 and this section. The required fire-resistance rating of exterior walls with a fire-separation distance of greater than 10' shall be rated for exposure to fire from the inside. The required fire-resistance rating of exterior walls with a fire-separation distance of less than or equal to 10' shall be rated for exposure to fire from both sides. The stair tower will be rated from both sides of the wall assembly facing the duplex. Best Regards, Jessie Davey-Mallo June 14, 2018, 10:02 AM Jesse, I'll look more when I back on Monday but if memory serves, residential code requires rating for distance < 5', nothing else. I don't remember the distance between those buildings. Residential fire protection is 5/8 gypsum and non-combustibable siding. Louis Hasbrouck City of Northampton, Town of Williamsburg (413) 587-1240 June 20, 2018, 11:10 AM Jesse, As long as the separation is > 5', only the apartment building needs fire protection; residential code table R302.1 (1) Louis Hasbrouck City of Northampton, Town of Williamsburg (413) 587-1240 Selected Code References 2009 IBC TABLE 601 FIRE-RESISTANCE RATING REQUIREMENTS FOR BUILDING ELEMENTS Exterior Bearing Walls in Type VB Construction: 0 Hours Exterior Non-Bearing Walls in Type VB Construction: See Table 602 2009 & 2015 IBC TABLE 602 FIRE-RESISTANCE RATING REQUIREMENTS FOR EXTERIOR WALLS BASED ON FIRE SEPARATION DISTANCE 5’ ≤ X < 10’ (1) Hour 2009 IRC TABLE R302.1 EXTERIOR WALLS Walls Not Fire-Resistance Rated X ≥ 5’ (0) Hours Projections Not Fire-Resistance Rated X ≥ 5’ (0) Hours Openings X = 3’ 0 Hours 2009 IEBC SECTION 703 BUILDING ELEMENTS AND MATERIALS 703.2.1 EXISTING VERTICAL OPENINGS All existing interior vertical openings connecting two or more floors shall be enclosed with approved assemblies having a fire-resistance rating of not less than 1 hour with approved opening protectives. Exception 11. In group R-2 occupancies, a minimum of 30-minute enclosure shall be provided to protect all vertical openings not exceeding three stories. This enclosure, or the enclosure specified in Section 703.2.1, shall not be required in the following locations: 11.2 Buildings protected throughout by an approved automatic sprinkler system. 11.3 Buildings with not more than four dwelling units per floor where every sleeping room above the second floor is provided with direct access to a fire escape or other approved second exit by means of an approved exterior door or window having a sill height of not greater than 44 inches and the building is protected throughout by an automatic fire alarm system complying with Section 704.4.