Roof Drainage. Dead level
roofs are not permitted. Roof
Exterior Doors. Entrance doors may be aluminum and/or
drains or scuppers are the only low points permitted.
glass of heavy duty construction. Glazed exterior doors
Provide a minimum slope to drains of 1:50 on roofing
and frames shall be steel and meet the requirements of
surfaces. When providing roof slope, consider sloping the
SDI Grade III with a G-90 galvanic zinc coating.
structural roof deck. Over the life of the building this may
Vestibules are desired to control air infiltration. Sliding
be less expensive than providing tappered insulation
automatic doors are preferred over swinging type. Motion
each time the roof is replaced. Roofs shall not be used to
detectors and push plates are preferred over mats as
Insulation. Roof insulation should be installed in a
Overhead coiling doors are preferred for loading docks. At
minimum of two layers to minimize thermal breaks in
least one personnel door should be provided in addition
the roof system.
to the overhead doors.
Access to Roof. An interior permanent stair should be
Hardware for Exterior Doors. Hinges, hingepins and hasps
provided to permit access to roof-mounted equipment.
must be secured against unauthorized removal by using
Permanent access to all roof levels should be provided to
spot welds or peened mounting bolts. All exterior doors
facilitate reoccurring inspection and maintenance.
must have automatic closers. The exterior side of the door
shall have a lock guard or astragal to prevent jimmying of
Roof-Mounted Equipment. Roof-mounted equipment shall
the latch hardware. Doors used for egress only should not
be kept to a minimum and must be housed in penthouses
have any operable exterior hardware. See Chapters 7 and 8
or screened by walls. Penthouses and screen walls should
for additional information.
be integrated into the building design and constructed of
materials used elsewhere in the building exterior. Some
All public entrances provided in accordance with
Paragraph F206.4.1 (Public Entrances) of the ABAAS shall
rods, flagpoles, etc., do not have to be screened, but these
have at least one entrance door complying with Section
elements must be integrated into the building design.
404.3 (Automatic and Power-Assisted Doors and Gates) of
Roof-mounted equipment should be elevated as
the ABAAS. Where a public entrance has a vestibule with
recommended in the NRCA Roofing and Waterproofing
exterior and interior entrance doors, at least one exterior
Manual and set back from the roof edge to minimize
door and at least one interior door shall comply with
visibility. Critical roof-mounted equipment should be
installed in such a way to permit roof system replacement
Roofing. Roofing design shall follow the recommenda-
or maintenance without disruption of equipment
tions of the National Roofing Contractors Association as
contained in NRCA publication, NRCA Roofing and
Penetrations through the roof to support equipment are
Waterproofing Manual. The design of metal flashing, trim,
extremely vulnerable to leaks. Flashing details must be
and roofing shall follow the recommendations of the
studied for appropriate continuation of the waterproof
Sheet Metal and Air Conditioning Contractors' National
barrier. Pitch pocket details should not be used.
Association (SMACNA) publication, Architectural Sheet
Revised March 2005 PBS-P100