A&P advised that clarfication of code requirements where a two hour fire rated
"blanket" wrapping system is applied to ductwork enclosed within a fire rated
mechanical shaft, may permit eliminating either the rated enclosure or the
blanket wrapping system. KH will review with
RJA; and,
A&P will consult with the City, and report to JV.
- Pre Function
Amit advised that A&P needs information ASAP on what kind of diffusers
are required for the Pre Function area?
Ivan advised that Clonia has notified Peter that this information is
needed.
- Basement.
Allen indicated that one of the mechanical shafts should not continue to
the basement floor.
- Elevator Cores 7 and 8.
Janet advised that the KH design provides 307 SF rather than 320 SF
previously requested by A&P.
Janet showed drawings of elevators at floors 1 - 3.
Amit indicated the KH design is okay for A&P requirements.
John advised that A&P needs 6" clear at the lavatory chase wall.
John wants to avoid pipe chase runs directly over beams.
Jannett reported that KH has done this.
- Restrooms.
Janet showed a sketch KH has underway to layout restrooms.
John suggested that KH design a double wall by turning wall studs
sideways to provide a space for piping, rather than have the piping
penetrate the wall studs.
John asked about sloping floors, and whether there will be a curb in the
restrooms for waterproofing?
KH advised that there will not a concrete curb, but there will be a
terazzo wall base.
John asked that drains be located away from floor beams.
[On Oct 15,
coordination with SDE
on structural issues.]
Ivan reported KH is following suggestion by Clonia Cautis to use details
from Moscone II on restroom floors.
Janet has reviewed dimensions with Clonia.
John indicated the KH drawings shown by Janet at the meeting today do not
present any evident problems for A&P's design.
- Elevator Cores.
Ivan showed a sketch prepared by KH that indicates potential conflicts
between elevator frame support, restroom piping, and water closet
carrier.
Michael suggested an alternate route for waste pipe, and floor drains.
A&P agreed to the alternate route.
Ivan asked if a column will interfere with the plumbing carrier; John
indicated the current dimensioning may present a conflict.
- Michael reported that KH submitted a detail to the elevator consultant of
ductwork in relation to the elevator machine room.
The elevator consultant has responded by modifying the shaft size.
- Duct Shaft at Elevators 7 & 8
AA is concerned that ducts are obstructed by structural beams.
AA advised this shaft will contain two ducts and will require 2 hour
wall rating.
IR asked if the shaft needs to split into 2 separate shafts?
Allen suggested eliminating the ducts, and simply use the architectural
shaft with a damper at the roof. Horizontal ducts would connect to the
vertical shaft.
Ivan advised that this design would require thorough documentation to
establish the extent to which the 2 hour shaft can be eliminated.
Michael noted complex design at B Line which may require increasing the
size of the shaft.
- Ductwork at Penthouse on Roof.
Allen showed a sketch A&P prepared for ductwork at the roof penthouse.
PB reported possible conflicts with ducts, bracing and stairs in the
elevator mechanical room.
Amit noted that A&P may have to move the ducts to avoid the conflict
with the stair.
- Duct Sizes on A&P Drawings
Ivan asked which size criteria KH should use for detailing ductwork in
ceilings and walls, where size notations on A&P drawings conflict with
scaled dimensions?
Allen said to use the scaled dimensions, because the size notations have
not yet been updated.
- Grease Duct
Michael requested confirmation of changes to the grease duct.
Allen advised that A&P has not changed the size of the grease ducts.
Michael showed a drawing indicating the size is 14 X 16.
Allen says 14 x 16 is wrong. He advised that KH should use the size
based on the prior drawings.
"Blanket" Wrapping System May Permit Omitting Shaft
Amit indicated an alternate design would be to eliminate the 2 hour rated
architectural wall shaft, and instead wrap the ducts with a 2 hour rated
"blanket" system.
Allen reported that preliminary discussion with City officials who
interpret the mechanical code, indicates it may be permissible to
elimiante the 2 hour shaft, if a "blanket" system of comparable rating is
used.
Ivan asked what A&P has learned about whether satisfying the mechanical
code requirement for a 2 hour rating, also satisfies the building code
requirement for a 2 hour shaft where ducts penetrate floor levels?
Allen advised this is a "grey" area, the code seems unclear.
There was concern that even if City code officials indicate approval
during the design phase, the system could still be rejected during City
plan check review, or later by City inspectors during construction.
There was discussion that Clonia Cautis may be able to resolve the issue
for the JV team, through discussions with the City Building Code
officials, or based on Gensler's experience with comparable work.
Amit advised that the "blanket wrap" system is expensive, so there is
incentive to limit its application. If it permits omitting construction
of a 2 hour rated shaft, then it would seem to be the less expensive
solution.
Michael advised that bracing and trusses at B Line make it difficult to
design and construct an adequately sized shaft. Wrapping the ducts with a
2 hour rated "blanket" system, may be a solution.
Another solution would be to use the "blanket wrap" system only on
horizontal runs from the kitchen to the shaft.
There was discussion that if a shaft is used, it should extend to the
roof and will require a vent.
Michael asked if the mechanical shaft can be eliminated at the 3rd floor
mezzanine if the blanket wrapping system used?