Building E to Building A – West window and door – Unprotected openings are within 3 feet from intersection of Fire Walls.New intersecting exterior walls are 1-hour rated at the fire wall intersections for a distance of 4’-0” minimum. The existing building walls are URM load-bearing walls with equivalent to 2-hour fire rating. Design proposes the fire walls terminate in accordance with 706 and to protect the openings within 4 feet of intersection with water curtain automatic sprinkler coverage. The historic school building has large existing openings adjacent to the intersection of fire walls at exterior walls. The relation of the imaginary lot line shall be such that exterior wall rating and opening protection complies with 705.5 and 705.ħ05.8.2 Opening protectives are not required where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.2.1.1 and the exterior openings are protected by a water curtain using automatic sprinklers approved for that use.Īutomatic sprinkler water curtain protection of window openings at fire wall termination per 705.8.2. Buildings or spaces on both sides of the intersection fore walls shall assume to have an imaginary lot line extending beyond the exterior of the fire wall.The fire resistance rating of the exterior wall shall extend not less than 4 feet each side of the intersection of the fire wall to exterior walls. Exterior walls shall have a 1-hour fire resistance with ¾-hour protection where opening protection is required per 705.8.Where the fire wall intersects exterior walls, the fire-resistance rating and opening protection of the exterior walls shall comply with one of the following: Please see Exhibits: SK-3A, SK-3B, SK-3C, and SK-3D, SK-3E and, SK-3F, and SK-3 Details, for revised information. Graphics of each location have been updated with the updated Imaginary Property Line locations. Details of opening protection via water curtain has been provided indicating sprinkler head location for the openings.
The Imaginary Property Lines have been adjusted such that a path to compliance is achieved. Reconsideration text for Appeal ID: 25110, Item 12: OSSC 705.8.2 Protected Openings and 706.5.1 Exterior Walls