M E E T I N G  N O T E S

Gensler/Michael Willis/Kwan Henmi

Project Moscone Center Expansion- Phase III Project Number 01.6250.000
Meeting Location JV Team Project Office Meeting Date October 14, 1998
Subject Mechanical Coordination Meeting Number



JV Team/KH
JV Team/KH
JV Team/KH
JV Team/KH
Ivan Romero (IR)
Michael Foegelle (MF)
Janet MacKinnon (JM)
Philip Buscemi (PB)
Allen Arbabaraghi (AA)
Amit Wadhwa (AW)
John Byrne (JB)


A&P suggests potential cost savings from eliminating some horizontal 2 hour shafts by using fire rated blanket wrapping. A&P will report on results of code research.

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.

  1. 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.

  2. Basement.

    Allen indicated that one of the mechanical shafts should not continue to the basement floor.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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?

Action / Decisions Pending / Follow up

Dual slot diffuser will be used.

A&P provided a drawing showing which mechanical shaft does not reach the floor of the basement.

KH will provide clearance requested by A&P.

A&P will submit a detail today at the toilet carrier for KH layout of restrooms and plumbing.

KH will change the design of restroom walls so the studs are sideways to provide a chase for plumbing piping.

John said that A&P will provide a large scale drawing and a "cut" of the plumbing carrier

KH will do an overlay analysis of plumbing, structural and other elements to resolve conflicts, including relocate beams and/or increase the size of the chase.

A&P will investigate and report to JV if code permits eliminating vertical ducts by connecting horizontal duct work to a 2 hour rated architectural shaft.

KH will request that RJA review this issue.

KH will submit a sketch later today to A&P showing details of this condition.

A&P will prepare a sketch showing an alternate duct route that avoids the conflict with the stair.

A&P will provide a drawing today for the grease duct, showing the correct size notations.

KH will consult with RJA for direction on designing 2 hour shafts with 2 hour blanket wrap on ductwork.

A&P will study this matter and consult with mechanical code officials for clarification on use of 2 hour blanket wrap system.

Gensler/Michael Willis/Kwan Henmi will rely on these notes as the approved record of matters discussed and conclusions reached during this meeting unless written notice to the contrary is received by Gensler/Michael Willis/Kwan Henmi within seven calendar days of the issue date of these meeting notes.


  1. GWK, Clonia Cautis
  2. GWK, Steven Hergert
  3. GWK, Bolivar Puyol
  4. The Engineering Enterprise, KC Hogan

Prepared by Ivan Romero Date Issued: 10/21/98

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