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Mr. Audie Wallace <br /> McKinstry Co., LLC <br /> Plan Check Number: X1907-001, Second Building Review <br /> August 29, 2019 <br /> Structural <br /> 1. This comment has not been addressed; the original comment is provided below. The response <br /> stated that independent support and bracing are not required, and cited ASCE 7-10 Section <br /> 13.6.7. This section is intended to enforce designing HVAC and ductwork for seismic forces, as <br /> stated in the first sentence. This is further emphasized by the commentary, which states that <br /> "bracing in accordance with ANSI/SMACNA"is effective in resisting seismic loads; design per <br /> SMACNA is not an alternative to providing bracing. Section 13.6.7 includes exceptions for when <br /> ductwork bracing may be omitted. However, the presence of the heavy concentrated loads <br /> from the inline units disqualifies the use of the exceptions, and therefore bracing is required. <br /> This may be accomplished by providing bracing to the ductwork instead of the unit directly if <br /> the unit weight does not exceed 75 pounds. Per the commentary, the connection between the <br /> unit and ductwork must still be explicitly designed for the seismic load. The connection and <br /> ductwork must also be able to transfer the unit weight to the ductwork supports. Where the <br /> unit weight exceeds 75 lbs, or the connection and ductwork have not been explicitly designed <br /> to transfer the weight and seismic loads of the unit to the ductwork supports and seismic <br /> bracing, then independent support and bracing of the unit is required. <br /> The project includes four air terminal units per Sheet M0.02. It is presumed that the units <br /> weight approximately 50 lbs each and will require individual gravity suspension and seismic <br /> bracing. See IBC Sections 107.2.1, 1604.1, and 1613.1, and ASCE 7-10 Section 14.1.4 Item 6c. <br /> The following comment shall be addressed: <br /> a. Details for the support of the units shall be included in the construction drawings. <br /> b. Calculations for the support design shall be submitted for review. The seismic bracing shall <br /> comply with the requirements of IBC Section 13.6. <br /> c. It is anticipated that the anchorage will include post-installed concrete anchors connecting <br /> to the concrete floor slab above. The drawings shall specify special inspection for the <br /> anchors. The types and frequency of the inspections shall be listed. See IBC Sections <br /> 1704.3 and 1704.3.1, and Table 1705.3 Item 4. <br /> This review has been performed for general compliance with the building codes as adopted and <br /> amended by the state of Washington and the city of Everett. Corrections and comments made <br /> during the review process do not relieve the project from compliance with code and permit <br /> requirements. The designers-of-record are responsible for a complete design in accordance with <br /> the laws of the state of Washington. <br /> If you have any questions or require additional clarification, please contact us. <br /> Respectfully, <br /> Drew Martin, P.E., S.E. <br /> Associate Engineer/ Commercial Plans Examiner <br /> (425)257-8813 <br /> dmartin@everettwa.gov <br /> S:\BMartin\2019\X1907-001_R2.docx <br /> O3200 Cedar Street © 425.257.8810 0 everetteps@everettwa.gov <br /> Everett,WA 98201 425.257.8857 fax everettwa.gov/permits <br /> Page 3 of 3 <br />