3030 HOYT AVE NORCO MEDICAL 2019-03-27

DEI DIBBLE ENGINEERS INC August 8,2018 Mr. Brian Lewis Total System Services 8227 44th Ave W,Suite G Mukilteo, WA 98275 Re: Norco RTU Replacement DEI Job#: 18-318 Dear Mr. Lewis: Dibble Engineers, Inc.(DEI)has completed a review of the new Rooftop Unit(RTU)proposed for installation at the Norco commercial building located at 3030 Hoyt Ave in Everett,WA 98201.DEI's scope of review is limited to structural feasibility of the existing building roof framing to support the new RTU. One existing Rooftop Unit installed at the building Is proposed to be removed and replaced with a new unit.Thi existing unit is a York brand 5-ton capacity BCH060 series model with a maximum weight of 620 pounds. The new proposed unit is a York brand 5-ton capacity XN036 series model with a maximum operating weight of 632 pounds. The new unit is proposed to be installed in the same location as the existing unit. Per our review,the replacement of the existing RTU with the new unit will be structurally acceptable.The increased weight and loading on the existing roof structure from the new rooftop unit was found to be within a 5 percent difference of the loading from the existing unit. Per IEBC 2012 Section 706.2 regarding Level 1 Alterations for addition or replacement of equipment: "Where addition or replacement of roofing or replacement of equipment results in additional dead loads, structural components supporting such reroofing or equipment shall comply with the gravity load requirements of the International Building Code. Exceptions: 1. Structural elements where the additional dead load from the roofing or equipment does not increase the force in the element by more than 5 percent." The increased loading due to the higher maximum weight of the new unit was found to be less than a 5 percent increase over the existing unit.As such,the IEBC exception listed above applies and no further strengthening or additional roof framing support will be required. Dibble Engineers review is limited to the support of the 5-ton capacity rooftop units as described above. Dibble Engineers did not conduct a comprehensive building analysis for either vertical or lateral loads. DEI's scope of analysis does not include the anchorage of the rooftop units to the roof framing or the structural integrity of the units themselves. Unless specifically discussed in our review, no other conditions were evaluated or considered. Our review and discussion summary does not provide warranty either expressed or implied to the existing conditions. DIBBLE ENGINEERS INC 11029 Market Street, Kirkland WA 98033 1425.828.42001 dibbleengineers.com