If there are not asphalt shingles and it meets the manufacturer specs for install, I can't find why not but you may still need to get it approved.
CHAPTER 9: ROOF ASSEMBLIES
SECTION R905 REQUIREMENTS FOR ROOF COVERINGS
R905.1 Roof covering applications. Roof coverings shall be applied in accordance with the applicable provisions of this section and the
manufacturer’s installation instructions.
R905.2 Asphalt shingles. The installation of asphalt shingles shall comply with the provisions of this section.
R905.2.1 Sheathing requirements. Asphalt shingles shall be fastened to solidly sheathed decks.
R905.2.2 Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (2:12) or greater. For
roof slopes from two units vertical in 12 units horizontal (2:12) up
to four units vertical in 12 units horizontal (4:12), double
underlayment application is required in accordance with Section
R905.2.7.
R905.2.3 Underlayment. Unless otherwise noted, required underlayment shall conform to ASTM D 226 Type I, ASTM D 4869 Type I,
or ASTM D 6757. Self-adhering polymer modified bitumen sheet shall
comply with ASTM D 1970.
R905.2.7 Underlayment application. For roof slopes from two
units vertical in 12 units horizontal (17-percent slope), up to four
units vertical in 12 units horizontal (33-percent slope), underlayment
shall be two layers applied in the following manner. Apply a 19-inch
(483 mm) strip of underlayment felt parallel to and starting at the
eaves, fastened sufficiently to hold in place. Starting at the eave,
apply 36-inch-wide (914 mm) sheets of underlayment, overlapping
successive sheets 19 inches (483 mm), and fastened sufficiently to
hold in place. Distortions in the underlayment shall not interfere
with the ability of the shingles to seal. For roof slopes of four
units vertical in 12 units horizontal (33-percent slope) or greater,
underlayment shall be one layer applied in the following manner.
Underlayment shall be applied shingle fashion, parallel to and
starting from the eave and lapped 2 inches (51 mm), fastened
sufficiently to hold in place. Distortions in the underlayment shall
not interfere with the ability of the shingles to seal. End laps shall
be offset by 6 feet (1829 mm).
CHAPTER 1 ADMINISTRATION
SECTION 104 DUTIES AND POWERS OF BUILDING OFFICIAL
104.11 Alternative materials, design and methods of construction and equipment. The provisions of this code are not intended to prevent
the installation of any material or to prohibit any design or method
of construction not specifically prescribed by this code, provided
that any such alternative has been approved. An alternative material,
design or method of construction shall be approved where the building
official finds that the proposed design is satisfactory and complies
with the intent of the provisions of this code, and that the
material, method or work offered is, for the purpose intended, at
least the equivalent of that prescribed in this code in quality,
strength, effectiveness, fire resistance, durability and safety. When
alternate life safety systems are designed, the
SFPE Engineering Guide to Performance-Based Fire Protection Analysis and Design of Buildings, or other methods approved by the building
official may be used. The building official shall require that
sufficient evidence or proof be submitted to substantiate any claim
made regarding the alternative.
Best Answer
Through other channels, I have found that the solution I need is non-fibrous aluminum coating available at most specialty roofing stores. I believe it has the viscosity of tar and is best applied using a stick brush.