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McPherson Engineering By: F.A. <br />Date: 3/6/23 <br />Existing Loads: <br />Roof Design Loads: <br />Roofing = 4.0 p.s.f.Rolled Composition roofing <br />Sheathing = 1.5 p.s.f.1/2" Plywood <br />Framing = 1.5 p.s.f.2x Framing <br />Misc = 1.0 p.s.f. <br />DLr1 = 8.0 p.s.f.Roofing Dead Load (applied to top of rafters/trusses only) <br />Ceiling = 2.0 p.s.f. Drywall and framing <br />DLr2 = 10.0 p.s.f. Total Existing Roof Dead Load <br />LLr = 20.0 p.s.f. Roof Live Load (Per C.B.C, Table 1607.1) <br />SL = 0.0 p.s.f.Snow Load <br />Floor Design Loads: (if applicable) <br />Flooring = 10.0 p.s.f.Weight of floor finish <br />Sheathing = 2.2 p.s.f.3/4" plywood <br />Framing = 2.0 p.s.f.2x framing or manufactured floor truss <br />Interior Partitions = 15.0 p.s.f.2x framed walls with drywall finish each side <br />Ceiling = 5.0 p.s.f.Drywall ceiling finish below <br />Misc. = 0.8 p.s.f. <br />DLf = 35.0 p.s.f.Total Existing Floor Dead Load <br />Proposed Loads: <br />Panels = 2.8 p.s.f. weight of panels including rack system <br />DLr1_proposed = 10.8 p.s.f. Proposed Roof Dead Load (applied to top only) <br />DLr2_proposed = 12.8 p.s.f.Total Proposed Roof Dead Load <br />LLr_proposed = 0.0 p.s.f. <br />Check Proposed Gravity Loads: <br />Total Existing Roof Load <br />Wex = (DLr1 + LLr) (Aroof) = 33.6 kips <br />Total Proposed Roof Load <br />Wprop = (DLr1 + LLr) (Aroof - Aarray) + (DLr1_proposed + LLr_proposed) (Aarray) = 27.6 kips <br />Proposed Load Demand <br />Gravity Loads <br />Roof Live Loads need not be applied to the area covered with by PV panel where the <br />clear space between the panels and the roof sureface is 24in or less, 1607.13.5.1 item 1 <br />Exception <br />Wprop - Wex = -17.98% TOTAL DECREASE IN GRAVITY LOADS, PANELS OK! <br />Wex <br />3/6/2023 11:32 AM <br />4 of 7 <br />©McPherson Engineering <br />821 N Lowell St <br />03/14/23