706.5.1
Exterior walls. 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:
1. The exterior walls on
both sides of the fire wall shall have a 1-hour
fire-resistance rating with
3/4-hour protection where
opening protection is required by Section 705.8. The fire-resistance
rating of the exterior wall shall extend a minimum of
4 feet (1220 mm) on each side of the intersection of the fire
wall to exterior wall. Exterior wall
intersections at fire walls that form an angle equal to or
greater than 180 degrees (3.14 rad) do not need exterior wall
protection.
2. Buildings or spaces
on both sides of the intersecting fire wall shall assume to
have an imaginary lot line at the fire wall
and extending beyond the exterior of the fire wall. The
location of the assumed line in relation to the exterior walls
and the fire wall shall be such that the exterior
wall and opening protection meet the requirements set forth in
Sections 705.5 and 705.8. Such protection is not required for exterior
walls terminating at fire walls that form an angle
equal to or greater than 180 degrees (3.14 rad).
706.5.2
Horizontal projecting
elements.
Fire walls shall extend to the outer edge of
horizontal projecting elements such as balconies, roof overhangs, canopies,
marquees and similar projections that are within 4 feet (1220 mm) of the
fire wall.
Exceptions:
1. Horizontal projecting elements without
concealed spaces, provided the exterior wall behind and below
the projecting element has not less than 1-hour fire-resistance-rated
construction for a distance not less than the depth of the projecting element
on both sides of the fire wall. Openings within such
exterior walls shall be protected by opening protectives
having a fire protection rating of not less than
3/4 hour.
2. Noncombustible horizontal projecting
elements with concealed spaces, provided a minimum 1-hour fire-resistance-rated
wall extends through the concealed space. The projecting element shall be
separated from the building by a minimum of 1-hour fire-resistance-rated
construction for a distance on each side of the fire wall
equal to the depth of the projecting element. The wall is not required to
extend under the projecting element where the building exterior
wall is not less than 1-hour fire-resistance rated for a distance on
each side of the fire wall equal to the depth of the
projecting element. Openings within such exterior walls shall
be protected by opening protectives having a fire protection
rating of not less than
3/4 hour.
3. For combustible horizontal projecting
elements with concealed spaces, the fire wall need only extend
through the concealed space to the outer edges of the projecting elements. The
exterior wall behind and below the projecting element shall be
of not less than 1-hour fire-resistance-rated construction for a distance not
less than the depth of the projecting elements on both sides of the
fire wall. Openings within such exterior
walls shall be protected by opening protectives having a
fire-protection rating of not less than
3/4 hour.
