Architectural and Engineering Design Standards

Rev. 13 November 1, 2016

Page | 51

22 14 13 Storm Sewer Piping Systems

1. Materials
   a. For typical storm sewer systems of 3” diameter and above, install cast iron (no-hub or bell-and-spigot) pipes.
   Tie all joints above 4” diameter to avoid blown apart joints.
   b. For typical storm sewer systems below 3“ diameter, install copper (ASTM B88, Type
   L) pipe.
   c. Install 1” fiberglass insulation, with all-service jacketing, on all:
   i. The initial interior section of piping from the roof drain to the first horizontal run of storm piping.
   ii. All horizontal runs of storm piping.
   iii. All exposed sections of storm piping.
   iv. Sections of storm piping in noise-sensitive areas, if such routing cannot be avoided.


2. Routings
   a. Cleanouts shall be provided at the first bend below the roof, at the base of all risers and at points where the
   system changes from horizontal to vertical or from vertical to horizontal.

22 14 23 Storm Drainage Piping Specialties

1. Cleanouts shall be line-size for storm mains up to 4” diameter. For storm mains above 4”
   Diameter, provide 4” clean-outs.

22 14 26 Facility Storm Drains

22 14 26.13 Roof Drains

1. Primary roof drains shall be of the beehive (dome) type, with drain bowls, clamping rings, under deck clamps,
   extension flanges, and domes being cast iron in composition. Clamping rings shall have four bolts. Drains with
   three bolts are not approved. Drain rims shall be elevated above the roof decking by setting the primary roof drain
   casting at deck level and installing a gasketed, threaded, adjustable extension flange with secondary clamping
   collar. Clamping collar elevation shall be lower than the roof surface elevation, but shall not result in steep roof
   transitions at roof drains. Roof system shall not be required to slope more than 1" per foot around drains.


2. Secondary drainage systems shall be installed through the use of secondary roof overflow drains with the top of
   the internal water dam set two inches higher than the primary roof drains. Overflow drain composition and
   method of setting shall be similar to that described for primary roof drains. However, overflow drain secondary
   clamping collar shall be set with elevation to be flush with the field of roof so as to prevent the need to sump the
   roof around overflow drains. Design overflow drains and coordinate with the roof system design, so as to prevent
   ponding of water around the overflow drains.


3. Primary roof drains shall be located at least 12" from adjacent perimeter parapet walls or roof penetrations
   requiring flashing.


4. Secondary roof drains shall be located at least 24" from adjacent primary roof drain and at least 12" from adjacent
   perimeter parapet walls or roof penetrations requiring flashing.


5. Approved Manufacturers:
   
   
   • Zurn
   
   
   • Josam
   
   
   • Wade
   
   
   • Jay R. Smith