Current through Register Vol. 48, No. 39, March 25, 2024
UPC chapter 11 is amended by adding a new section and
subsections as follows:
1110.0
Siphonic Roof Drainage System.
1110.1
General Requirements.
Siphonic roof drainage systems shall be designed as an engineered siphonic roof
drainage system when allowed by the administrative authority.
The engineered siphonic roof drainage system shall meet the
requirements of Sections 1110.2 and 1110.3.
1110.2
Design Criteria. The
siphonic roof drainage system shall be designed and certified by a registered
professional engineer.
1110.2.1
Sizing. The system shall be sized on the basis of a minimum rate of
rainfall of 4 inches per hour.
1110.2.2
Design. The drainage
system shall be designed according to ASPE Standard 45, Siphonic Roof Drainage,
and according to the manufacturers recommendations and requirements.
Manufacturer design software shall be in accordance with ASPE Standard
45.
1110.2.3
Roof drain
bodies. Roof drains shall meet ASME A112.6.9, Siphonic Roof
Drains.
1110.2.4
Water
accumulation. When designed for water accumulation, the roof shall be
designed for the maximum possible water accumulation according to Section
1108.1(7), as amended in this code, and Minnesota Rules, chapter
1305.
1110.2.5
Pipe size and
cleanouts.Minimum pipe size shall be 1-1/2 inches. All pipe sizes and
cleanouts in the drainage system shall be designed and installed according to
ASPE Standard 45.
1110.2.6
Horizontal pipes. Horizontal pipe size shall not reduce in the direction
of flow.
1110.2.7
Plans and
specifications. The plans and specifications for the drainage system
shall indicate the siphonic roof drainage system as an engineered method used
for the design.
1110.2.8
Markings. The installed drainage system shall be permanently and
continuously marked as a siphonic roof drainage system at approved intervals
and clearly at points where piping passes through walls and floors. Roof drains
shall be marked in accordance with ASME Al 12.6.9.
1110.2.9
Transition locations.
The transition locations from the siphonic roof drainage system to a gravity
system shall be determined by the registered professional engineer at a
location approved by the administrative authority. The design, sizing, and
venting of the transition location shall be in accordance with ASPE Standard
45. The gravity portion of the building storm sewer system receiving the
siphonic roof drainage system shall be sized for the design rate but not less
than a rainfall rate of 4 inches per hour and in accordance with Section
1106.0.
1110.2.10
Required
submissions. All plans, specifications, and calculations shall be signed
and sealed by the registered professional engineer and submitted to the
administrative authority. The submitted calculations shall include performance
data for the drainage system for the required rainfall rate, including the
minimum and maximum calculated operating pressures and velocities verifying
that the design solution is within the operating parameters required by the
design standard. All performance data shall be reported as the extreme maximum
and minimum calculations and shall not be presented as averaged data.
1110.3
Proof of
Suitability. Upon completion of the project: proper tests, inspections,
and certification of the siphonic roof drainage system shall be performed
according to items 1110.3.1 and 1110.3.2:
1110.3.1
Testing. Testing shall
be performed according to ASPE Standard 45.
1110.3.2
Written certification.
Prior to the final plumbing inspection, the registered professional engineer
shall provide written certification to the administrative authority that the
system has been visually inspected by the registered professional engineer or
the registered professional engineers designee and the installation has been
properly implemented according to the certified design, plans, calculations,
and specifications. The submitted written certification shall include any field
modification from the initial design involving dimensions, location, or routing
of the siphonic roof drainage system that shall be reapproved and recertified
by the registered professional engineer and be accompanied by a final as-built
design of the altered system and supported by calculated data to show that the
overall system remains in accordance with ASPE Standard 45.