2721 WETMORE AVE MARQUEE APARTMENTS 2023-06-28

Check B1906-031 2721Plan Wetmore Number Avenue Response to wood frame comments from Second Building Review,October 18, 2019 Structural: Item 11 11 a to 11 e. Roof Penthouse. See attached supplemental structural calculations for framing at the roof penthouse roof framing. As shown on Sheet S2.16,the roof framing is specified including the elevator hoist beam supplied by the elevator manufacturer. Roof sheathing is specified in the Structural Notes Sheet S1.02 Section 06500. Shear walls for this penthouse shall be Type P6 as shown on S2.16 and do not require holdowns. RE. S9.02 for added sections at Penthouse roof framing. Penthouse walls to roof and walls below RE. S9.01 for similar typical details. Structural/Gravity System: Item 18 18b and 18c. Previously submitted calculations considered the tributary area and corresponding design loading for each diagonal tension rod and its supporting wood columns. The rods are located at the two exterior corners of the typical bolted on deck with additional connections along the long side connected to the rim beam. With deck decking spanning exterior to interior, half the load is to the exterior rim. See attached calculations confirming that a rod within 9"maximum of the exterior edge is adequate. A typical deck has two diagonal braces along with two connections along its interior long side attached to the rim beam. At corner decks, one interior long side and one short side are attached to the building and one corner is supported by a diagonal brace.This occurs on the north end and south end of the west side of the building. RE 1/S9.02 for the diagonal brace to post connection and connections to the rim beam including sub-diaphragm connection to the framing. The prefabricated deck system including all connections to the rim beam are designed by design by the deck fabricator's structural engineer. Their design will be reviewed during the shop drawing process and submitted as a differed submittal per requirements of Structural Notes Section 01005 under the heading Differed Submittals. CTE has met with the deck fabricator and they understand this requirement. 18d. The curved decks located on the west side in the center of the building are custom designed prefabricated decks by others, not CTE. They are a series of cantilevered individual prefabricated decks connected to the rim beam and adjacent perpendicular framing, with include curved fascia beams. RE Arch Sheet A-10.0 and 6 &8/S9.02. See response to Item 18a and 18b above regarding differed submittal of all prefabricated deck and rail systems. RE supplemental calculations confirming the connection of these prefabricated cantilevered decks to the building. All connections will be verified again and all deck designs will be will be part of the differed submittal package including calculations by the deck fabricators engineer(not CTE.) Please note we have reviewed our details with the deck fabricator and they have confirmed the CTE details are OK with their system. They understand the requirement for calculations by their engineer as part of the differed submittal. Lateral System: Item 39 39a. Building story shears based on Equation 12.8-12 and wood diaphragm story shears based on Equation 12.10-1 were previously submitted. See attached copy from the supplemental calculations submitted in September 2019,for story shears and maximum diaphragm shears and diaphragm capacities. In the attached supplemental calculations we have corrected the diaphragm calculation to use diaphragm shears and confirm we are within code limits. Please also reference typical Detail 7/S9.00 for typical strap at the end of each wood frame shear wall attaching sub diaphragms to the end of each shear wall. 39b. Reference the structural notes Sheet S1.02 Section 06500 for specified floor and roof sheathing. It appears the reviewer did not review the structural notes when incorrectly assuming it was missing. 39c. Confirming,the previously submitted design of the wood frame lateral force resisting system and horizontal distribution of shears considered the open diaphragm configuration and associated torsional Page 12 -7)