1704.10.1 Structural member
surface conditions. The surfaces shall be prepared in
accordance with the approved fire-resistance design and
the approved manufacturer’s written instructions. The
prepared surface of structural members to be sprayed shall
be inspected before the application of the sprayed fire-resistant
material.
1704.10.2 Application.
The substrate shall have a minimum ambient temperature before
and after application as specified in the approved manufacturer’s
written instructions. The area for application shall be
ventilated during and after application as required by the
approved manufacturer’s written instructions.
1704.10.3 Thickness.
The average thickness of the sprayed fire-resistant materials
applied to structural elements shall not be less than the
thickness required by the approved fire-resistant design.
Individually measured thickness, which exceeds the thickness
specified in a design by 1/4 inch
(6.4 mm) or more, shall be recorded as the thickness specified
in the design plus 1/4 inch (6.4 mm).
For design thicknesses 1 inch (25 mm) or greater, the minimum
allowable individual thickness shall be the design thickness
minus 1/4 inch (6.4 mm). For design
thicknesses less than 1 inch (25 mm), the minimum allowable
individual thickness shall be the design thickness minus
25 percent. Thickness shall be determined in accordance
with ASTM E 605. Samples of the sprayed fire-resistant materials
shall be selected in accordance with Sections 1704.10.3.1
and 1704.10.3.2.
1704.10.3.1 Floor, roof
and wall assemblies. The thickness of the sprayed
fire-resistant material applied to floor, roof and wall
assemblies shall be determined in accordance with ASTM
E 605 by taking the average of not less than four measurements
for each 1,000 square feet (93 m2) of the sprayed area
on each floor or part thereof.
1704.10.3.2 Structural
framing members. The thickness of the sprayed fire-resistant
material applied to structural members shall be determined
in accordance with ASTM E 605. Thickness testing shall
be performed on not less than 25 percent of the structural
members on each floor.
1704.10.4 Density. The
density of the sprayed fire-resistant material shall not
be less than the density specified in the approved fire-resistant
design. Density of the sprayed fire-resistant material shall
be determined in accordance with ASTM E 605.
1704.10.5 Bond strength.
The cohesive/adhesive bond strength of the cured sprayed
fire-resistant material applied to structural elements shall
not be less than 150 pounds per square foot (psf) (7.18
kN/m2). The cohesive/adhesive bond strength shall
be determined in accordance with the field test specified
in ASTM E 736 by testing in-place samples of the sprayed
fire-resistant material selected in accordance with Sections
1704.10.5.1 and 1704.10.5.2.
1704.10.5.1 Floor, roof
and wall assemblies. The test samples for determining
the cohesive/adhesive bond strength of the sprayed fire-resistant
materials shall be selected from each floor, roof and
wall assembly at the rate of not less than one sample
for every 10,000 square feet (929 m2) or part
thereof of the sprayed area in each story.
1704.10.5.2 Structural
framing members. The test samples for determining
the cohesive/adhesive bond strength of the sprayed fire-resistant
materials shall be selected from beams, girders, joists,
trusses and columns at the rate of not less than one sample
for each type of structural framing member for each 10,000
square feet (929 m2) of floor area or part
thereof in each story.
