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21 -018 JB-010868-Vachelli Version #43.7 April 22, 2015 Project/Job # 010868 RE: CERTIFICATION LETTER Project: Vacchelli Residence 511 Sylvester Rd POLE 45Florence, MA 01062 To Whom It May Concern, Design Criteria: - Applicable Codes = MA Res. Code, 8th Edition, ASCE 7-05, and 2005 NDS - Risk Category = II - Wind Speed = 90 mph, Exposure Category C - Ground Snow Load = 40 psf - MP1A&B: Roof DL = 13 psf, Roof LL/SL = 21.6 psf (Non-PV Areas), Roof LL/SL = 21.6 psf (PV Areas) - MP1C-LOWER: Roof DL = 10 psf, Roof LL/SL = 21.6 psf (Non-PV Areas), Roof LL/SL = 21.6 psf (PV Areas) - MP1C-UPPER: Roof DL = 9 psf, Roof LL/SL = 21.6 psf (Non-PV Areas), Roof LL/SL = 21.6 psf (PV Areas) Note: Per IBC 1613.1; Seismic check is not required because Ss = 0.22424 < 0.4g and Seismic Design Category (SDC) = B < D Sincerely, Nick Gordon, P.E.Professional Engineer T: 888.765.2489 x58391 email: ngordon@solarcity.com A jobsite survey of the existing framing system was performed by a site survey team from SolarCity. Structural review was based on site observations and the design criteria listed below: I certify that the structural roof framing and the new attachments that directly support the gravity loading and wind uplift loading from PV modules have been reviewed and determined to meet or exceed structural strength requirements of the MA Res. Code, 8th Edition. Please contact me with any questions or concerns regarding this project. On the above referenced project, the components of the structural roof framing impacted by the installation of the PV assembly have been reviewed. After this review it has been determined that the existing structure is adequate to withstand the applicable roof dead load, PV assembly load, and live/snow loads indicated in the design criteria above. 04.22.2015 Version #43.7 Project Name:AHJ: Job Number:Building Code:Customer Name:Based On:Address:511 Sylvester Rd POLE 45 ASCE Code:City/State:Florence,MA Risk Category:Zip Code Upgrades Req'd?Latitude / Longitude:42.327042 -72.718748 Stamp Req'd?SC Office:PV Designer: Calculations:EOR: Certification Letter 1 Project Information, Table Of Contents, & Vicinity Map 2 Structure Analysis (Loading Summary and Member Check)3 Hardware Design (PV System Assembly)4 Note: Per IBC 1613.1; Seismic check is not required because Ss = 0.22424 < 0.4g and Seismic Design Category (SDC) = B < D Latitude: 42.327042, Longitude: -72.718748, Exposure Category: C 511 Sylvester Rd POLE 45, Florence, MA 01062 Grady Koupal Nick Gordon, P.E. 1/2-MILE VICINITY MAP Springfield Northampton MA Res. Code, 8th Edition IRC 2009 / IBC 2009 Yes Vacchelli Residence Vacchelli, Tony And Debbie ASCE 7-05 010868 David Caropresi No01062 II PV System Structural Design Software PROJECT INFORMATION & TABLE OF CONTENTS Overhang 0.99 ft Actual W 1.50'' Span 1 9.73 ft Actual D 7.25'' Number of Spans (w/o Overhang)2 Span 2 4.00 ft Nominal Yes Roofing Material Comp Roof Span 3 A 10.88 in.^2 Re-Roof No Span 4 Sx 13.14 in.^3 Plywood Sheathing Yes Span 5 Ix 47.63 in.^4 Board Sheathing None Total Span 14.72 ft TL Defl'n Limit 180 Vaulted Ceiling Yes PV 1 Start 1.33 ft Wood Species SPF Ceiling Finish 1/2" Gypsum Board PV 1 End 12.58 ft Wood Grade #2 Rafter Slope 45°PV 2 Start Fb 875 psi Rafter Spacing 24'' O.C.PV 2 End Fv 135 psi Top Lat Bracing Full PV 3 Start E 1400000 psi Bot Lat Bracing Full PV 3 End Emin 510000 psi Roof Pitch 12/12 Initial Pitch Adjust Non-PV Areas PV Areas Roof Dead Load DL 13.0 psf x 1.41 18.4 psf 18.4 psf PV Dead Load PV-DL 3.0 psf x 1.41 4.2 psf Roof Live Load RLL 20.0 psf x 0.60 12.0 psf Live/Snow Load LL/SL1,2 40.0 psf x 0.54 ǀ x 0.54 21.6 psf 21.6 psf Total Load (Governing LC)TL 40.0 psf 44.2 psf Governing Load Comb CD CL (+)CL (-)CF Cr D + S 1.15 1.00 1.00 1.2 1.15 Maximum Max Demand @ Location Capacity DCR Shear Stress 44 psi 1.0 ft.155 psi 0.28 Bending (+) Stress 597 psi 5.1 ft.1389 psi 0.43 Bending (-) Stress -697 psi 10.7 ft.-1389 psi 0.50 (Governs) Total Load Deflection 0.28 in. | L/590 5.4 ft.0.92 in. | L/180 0.31 Notes: 1. ps = Cs*pf; Cs -roof, Cs -pv per ASCE 7 [Figure 7-2] 2. pf = 0.7 (Ce) (Ct) (Is) pg ; Ce=0.9, Ct=1.1, Is=1.0 Member Design Summary (per NDS) Member Analysis Results Summary Roof System Properties Member Loading Summary STRUCTURE ANALYSIS - LOADING SUMMARY AND MEMBER CHECK - MP1A&B Member Properties Summary MP1A&B Horizontal Member Spans Rafter Properties PV System Load PV Module Weight (psf)2.5 psf Hardware Assembly Weight (psf)0.5 psf PV System Weight (psf)3.0 psf Roof Dead Load Load Roof Category Description Existing Roofing Material ( 2 Layers )5.0 psf Re-Roof Underlayment 0.5 psf Plywood Sheathing 1.5 psf Board Sheathing Rafter Size and Spacing 2 x 8 @ 24 in. O.C.1.5 psf Vaulted Ceiling 3.0 psf Miscellaneous 1.5 psf Total Roof Dead Load 13.0 psf Reduced Roof LL Non-PV Areas ASCE 7-05 Roof Live Load Lo Table 4-1 Member Tributary Area AtRoof Slope Tributary Area Reduction R1 Section 4.9 Sloped Roof Reduction R2 Section 4.9 Reduced Roof Live Load Lr Equation 4-2 Reduced Roof Live Load Lr 12.0 psf Code Ground Snow Load pg ASCE Table 7-1 Snow Load Reductions Allowed?From ENP Effective Roof Slope Horiz. Distance from Eve to Ridge W From ENP Snow Importance Factor Is Table 1.5-2 Eq: 7.3-170% ASCE Eq: 7.4-1 54% ASCE Eq: 7.4-1 54% Design Snow Load Over PV Modules ps-pv ps-pv = (Cs-pv) pf21.5 psf ASCE Design Sloped Roof Snow Load Over PV Modules Surface Condition of PV Modules Cs -pv All Other Surfaces Figure 7-20.8 Design Roof Snow Load Over Surrounding Roof ps-roof ps-roof = (Cs-roof) pf21.5 psf Figure 7-20.8 Flat Roof Snow Load pf pf = 0.7 (Ce) (Ct) (I) pg; pf ≥ pf-min 28.0 psf ASCE Design Sloped Roof Snow Load Over Surrounding Roof Surface Condition of Surrounding Roof Cs -roof All Other Surfaces 1.1Minimum Flat Roof Snow Load (w/ Rain-on-Snow Surcharge)pf-min 28.0 psf 7.3.4 & 7.10 Snow Thermal Factor Ct Structures kept just above freezing Table 7-3 45° 20.6 ft 1.0 Snow Exposure Factor Ce Fully Exposed Table 7-20.9 Reduced Ground/Roof Live/Snow Loads 40.0 psf Yes 0.6 Lr = Lo (R1) (R2) 12 psf (MP1A&B) 13 psf (MP1A&B) Value 20.0 psf < 200 sf 12/12 1 Roofing Paper Yes None Yes Miscellaneous Items LOAD ITEMIZATION - MP1A&B Material MP1A&B Comp Roof No Roofing Material PV System Type Spanning Vents Standoff (Attachment Hardware) Roof Slope Rafter Spacing Framing Type / Direction Wind Design Code Wind Design Method Basic Wind Speed V Fig. 6-1 Exposure Category Section 6.5.6.3 Roof Style Fig. 6-11B/C/D-14A/B Mean Roof Height h Section 6.2 Wind Pressure Exposure Kz Table 6-3 Topographic Factor Kzt Section 6.5.7 Wind Directionality Factor Kd Table 6-4 Importance Factor I Table 6-1 Ext. Pressure Coefficient (Up)GCp (Up)Fig. 6-11B/C/D-14A/B Ext. Pressure Coefficient (Down)GCp (Down)Fig. 6-11B/C/D-14A/B Design Wind Pressure p Equation 6-22 Wind Pressure Up p(up)Wind Pressure Down p(down) Y-Direction Max Allowable Standoff Spacing Landscape 39'' Max Allowable Cantilever Landscape NA Standoff Configuration Landscape Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR Y-Direction Max Allowable Standoff Spacing Portrait 65''Max Allowable Cantilever Portrait NAStandoff Configuration Portrait Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR 22 sf 3.0 psf-315 lbs 500 lbs 63.1% 500 lbs56.9% X-Direction 48'' 17'' Staggered Staggered 20 sf 3.0 psf -284 lbs 14.6 psf ALLOWABLE STANDOFF SPACINGS X-Direction 72'' 0.88 p = qh (GCp) -15.8 psf 24'' qh qh = 0.00256 (Kz) (Kzt) (Kd) (V^2) (I)Equation 6-1516.7 psf Wind Pressure -0.95 Wind Pressure Calculation Coefficients 0.95 1.00 0.85 1.0 Velocity Pressure 25 ft Wind Design Criteria ASCE 7-05 Partially/Fully Enclosed Method 90 mph C Gable Roof Y-Y Rafters No Comp Mount Type C 45° 24'' O.C. CALCULATION OF DESIGN WIND LOADS - MP1A&B Mounting Plane Information Comp Roof SolarCity SleekMount™ Overhang 0.99 ft Actual W 1.50'' Span 1 9.50 ft Actual D 7.25'' Number of Spans (w/o Overhang)1 Span 2 Nominal Yes Roofing Material Comp Roof Span 3 A 10.88 in.^2 Re-Roof No Span 4 Sx 13.14 in.^3 Plywood Sheathing Yes Span 5 Ix 47.63 in.^4 Board Sheathing None Total Span 10.49 ft TL Defl'n Limit 120 Vaulted Ceiling No PV 1 Start 1.33 ft Wood Species SPF Ceiling Finish 1/2" Gypsum Board PV 1 End 10.49 ft Wood Grade #2 Rafter Slope 45°PV 2 Start Fb 875 psi Rafter Spacing 24'' O.C.PV 2 End Fv 135 psi Top Lat Bracing Full PV 3 Start E 1400000 psi Bot Lat Bracing At Supports PV 3 End Emin 510000 psi Roof Pitch 12/12 Initial Pitch Adjust Non-PV Areas PV Areas Roof Dead Load DL 10.0 psf x 1.41 14.1 psf 14.1 psf PV Dead Load PV-DL 3.0 psf x 1.41 4.2 psf Roof Live Load RLL 20.0 psf x 0.60 12.0 psf Live/Snow Load LL/SL1,2 40.0 psf x 0.54 ǀ x 0.54 21.6 psf 21.6 psf Total Load (Governing LC)TL 35.7 psf 40.0 psf Governing Load Comb CD CL (+)CL (-)CF Cr D + S 1.15 1.00 0.45 1.2 1.15 Maximum Max Demand @ Location Capacity DCR Shear Stress 45 psi 1.0 ft.155 psi 0.29 Bending (+) Stress 792 psi 5.8 ft.1389 psi 0.57 (Governs) Bending (-) Stress -64 psi 1.0 ft.-630 psi 0.10 Total Load Deflection 0.42 in. | L/385 5.8 ft.1.34 in. | L/120 0.31 Notes: 1. ps = Cs*pf; Cs -roof, Cs -pv per ASCE 7 [Figure 7-2] 2. pf = 0.7 (Ce) (Ct) (Is) pg ; Ce=0.9, Ct=1.1, Is=1.0 Member Design Summary (per NDS) Member Analysis Results Summary Roof System Properties Member Loading Summary STRUCTURE ANALYSIS - LOADING SUMMARY AND MEMBER CHECK - MP1C-LOWER Member Properties Summary MP1C-LOWER Horizontal Member Spans Rafter Properties PV System Load PV Module Weight (psf)2.5 psf Hardware Assembly Weight (psf)0.5 psf PV System Weight (psf)3.0 psf Roof Dead Load Load Roof Category Description Existing Roofing Material ( 2 Layers )5.0 psf Re-Roof Underlayment 0.5 psf Plywood Sheathing 1.5 psf Board Sheathing Rafter Size and Spacing 2 x 8 @ 24 in. O.C.1.5 psf Vaulted Ceiling Miscellaneous 1.5 psf Total Roof Dead Load 10.0 psf Reduced Roof LL Non-PV Areas ASCE 7-05 Roof Live Load Lo Table 4-1 Member Tributary Area AtRoof Slope Tributary Area Reduction R1 Section 4.9 Sloped Roof Reduction R2 Section 4.9 Reduced Roof Live Load Lr Equation 4-2 Reduced Roof Live Load Lr 12.0 psf Code Ground Snow Load pg ASCE Table 7-1 Snow Load Reductions Allowed?From ENP Effective Roof Slope Horiz. Distance from Eve to Ridge W From ENP Snow Importance Factor Is Table 1.5-2 Eq: 7.3-170% ASCE Eq: 7.4-1 54% ASCE Eq: 7.4-1 54% Design Snow Load Over PV Modules ps-pv ps-pv = (Cs-pv) pf21.5 psf ASCE Design Sloped Roof Snow Load Over PV Modules Surface Condition of PV Modules Cs -pv All Other Surfaces Figure 7-20.8 Design Roof Snow Load Over Surrounding Roof ps-roof ps-roof = (Cs-roof) pf21.5 psf Figure 7-20.8 Flat Roof Snow Load pf pf = 0.7 (Ce) (Ct) (I) pg; pf ≥ pf-min 28.0 psf ASCE Design Sloped Roof Snow Load Over Surrounding Roof Surface Condition of Surrounding Roof Cs -roof All Other Surfaces 1.1Minimum Flat Roof Snow Load (w/ Rain-on-Snow Surcharge)pf-min 28.0 psf 7.3.4 & 7.10 Snow Thermal Factor Ct Structures kept just above freezing Table 7-3 45° 20.6 ft 1.0 Snow Exposure Factor Ce Fully Exposed Table 7-20.9 Reduced Ground/Roof Live/Snow Loads 40.0 psf Yes 0.6 Lr = Lo (R1) (R2) 12 psf (MP1C-LOWER) 10 psf (MP1C-LOWER) Value 20.0 psf < 200 sf 12/12 1 Roofing Paper Yes None No Miscellaneous Items LOAD ITEMIZATION - MP1C-LOWER Material MP1C-LOWER Comp Roof No Roofing Material PV System Type Spanning Vents Standoff (Attachment Hardware) Roof Slope Rafter Spacing Framing Type / Direction Wind Design Code Wind Design Method Basic Wind Speed V Fig. 6-1 Exposure Category Section 6.5.6.3 Roof Style Fig. 6-11B/C/D-14A/B Mean Roof Height h Section 6.2 Wind Pressure Exposure Kz Table 6-3 Topographic Factor Kzt Section 6.5.7 Wind Directionality Factor Kd Table 6-4 Importance Factor I Table 6-1 Ext. Pressure Coefficient (Up)GCp (Up)Fig. 6-11B/C/D-14A/B Ext. Pressure Coefficient (Down)GCp (Down)Fig. 6-11B/C/D-14A/B Design Wind Pressure p Equation 6-22 Wind Pressure Up p(up)Wind Pressure Down p(down) Y-Direction Max Allowable Standoff Spacing Landscape 39'' Max Allowable Cantilever Landscape NA Standoff Configuration Landscape Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR Y-Direction Max Allowable Standoff Spacing Portrait 65''Max Allowable Cantilever Portrait NAStandoff Configuration Portrait Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR 22 sf 3.0 psf-315 lbs 500 lbs 63.1% 500 lbs56.9% X-Direction 48'' 17'' Staggered Staggered 20 sf 3.0 psf -284 lbs 14.6 psf ALLOWABLE STANDOFF SPACINGS X-Direction 72'' 0.88 p = qh (GCp) -15.8 psf 24'' qh qh = 0.00256 (Kz) (Kzt) (Kd) (V^2) (I)Equation 6-1516.7 psf Wind Pressure -0.95 Wind Pressure Calculation Coefficients 0.95 1.00 0.85 1.0 Velocity Pressure 25 ft Wind Design Criteria ASCE 7-05 Partially/Fully Enclosed Method 90 mph C Gable Roof Y-Y Rafters No Comp Mount Type C 45° 24'' O.C. CALCULATION OF DESIGN WIND LOADS - MP1C-LOWER Mounting Plane Information Comp Roof SolarCity SleekMount™ Overhang Actual W 1.50'' Span 1 4.00 ft Actual D 3.50'' Number of Spans (w/o Overhang)1 Span 2 Nominal Yes Roofing Material Comp Roof Span 3 A 5.25 in.^2 Re-Roof No Span 4 Sx 3.06 in.^3 Plywood Sheathing Yes Span 5 Ix 5.36 in.^4 Board Sheathing None Total Span 4.00 ft TL Defl'n Limit 120 Vaulted Ceiling No PV 1 Start 0.01 ft Wood Species SPF Ceiling Finish 1/2" Gypsum Board PV 1 End 3.00 ft Wood Grade #2 Rafter Slope 45°PV 2 Start Fb 875 psi Rafter Spacing 24'' O.C.PV 2 End Fv 135 psi Top Lat Bracing Full PV 3 Start E 1400000 psi Bot Lat Bracing At Supports PV 3 End Emin 510000 psi Roof Pitch 12/12 Initial Pitch Adjust Non-PV Areas PV Areas Roof Dead Load DL 9.0 psf x 1.41 12.7 psf 12.7 psf PV Dead Load PV-DL 3.0 psf x 1.41 4.2 psf Roof Live Load RLL 20.0 psf x 0.60 12.0 psf Live/Snow Load LL/SL1,2 40.0 psf x 0.54 ǀ x 0.54 21.6 psf 21.6 psf Total Load (Governing LC)TL 34.3 psf 38.6 psf Governing Load Comb CD CL (+)CL (-)CF Cr D + S 1.15 1.00 0.95 1.5 1.15 Maximum Max Demand @ Location Capacity DCR Shear Stress 26 psi 155 psi 0.17 Bending (+) Stress 596 psi 2.0 ft.1736 psi 0.34 (Governs) Bending (-) Stress 0 psi -1655 psi 0.00 Total Load Deflection 0.12 in. | L/582 2.0 ft.0.57 in. | L/120 0.21 Notes: 1. ps = Cs*pf; Cs -roof, Cs -pv per ASCE 7 [Figure 7-2] 2. pf = 0.7 (Ce) (Ct) (Is) pg ; Ce=0.9, Ct=1.1, Is=1.0 Member Design Summary (per NDS) Member Analysis Results Summary Roof System Properties Member Loading Summary STRUCTURE ANALYSIS - LOADING SUMMARY AND MEMBER CHECK - MP1C-UPPER Member Properties Summary MP1C-UPPER Horizontal Member Spans Rafter Properties PV System Load PV Module Weight (psf)2.5 psf Hardware Assembly Weight (psf)0.5 psf PV System Weight (psf)3.0 psf Roof Dead Load Load Roof Category Description Existing Roofing Material ( 2 Layers )5.0 psf Re-Roof Underlayment 0.5 psf Plywood Sheathing 1.5 psf Board Sheathing Rafter Size and Spacing 2 x 4 @ 24 in. O.C.0.7 psf Vaulted Ceiling Miscellaneous 1.3 psf Total Roof Dead Load 9.0 psf Reduced Roof LL Non-PV Areas ASCE 7-05 Roof Live Load Lo Table 4-1 Member Tributary Area AtRoof Slope Tributary Area Reduction R1 Section 4.9 Sloped Roof Reduction R2 Section 4.9 Reduced Roof Live Load Lr Equation 4-2 Reduced Roof Live Load Lr 12.0 psf Code Ground Snow Load pg ASCE Table 7-1 Snow Load Reductions Allowed?From ENP Effective Roof Slope Horiz. Distance from Eve to Ridge W From ENP Snow Importance Factor Is Table 1.5-2 Eq: 7.3-170% ASCE Eq: 7.4-1 54% ASCE Eq: 7.4-1 54% Design Snow Load Over PV Modules ps-pv ps-pv = (Cs-pv) pf21.5 psf ASCE Design Sloped Roof Snow Load Over PV Modules Surface Condition of PV Modules Cs -pv All Other Surfaces Figure 7-20.8 Design Roof Snow Load Over Surrounding Roof ps-roof ps-roof = (Cs-roof) pf21.5 psf Figure 7-20.8 Flat Roof Snow Load pf pf = 0.7 (Ce) (Ct) (I) pg; pf ≥ pf-min 28.0 psf ASCE Design Sloped Roof Snow Load Over Surrounding Roof Surface Condition of Surrounding Roof Cs -roof All Other Surfaces 1.1Minimum Flat Roof Snow Load (w/ Rain-on-Snow Surcharge)pf-min 28.0 psf 7.3.4 & 7.10 Snow Thermal Factor Ct Structures kept just above freezing Table 7-3 45° 20.6 ft 1.0 Snow Exposure Factor Ce Fully Exposed Table 7-20.9 Reduced Ground/Roof Live/Snow Loads 40.0 psf Yes 0.6 Lr = Lo (R1) (R2) 12 psf (MP1C-UPPER) 9 psf (MP1C-UPPER) Value 20.0 psf < 200 sf 12/12 1 Roofing Paper Yes None No Miscellaneous Items LOAD ITEMIZATION - MP1C-UPPER Material MP1C-UPPER Comp Roof No Roofing Material PV System Type Spanning Vents Standoff (Attachment Hardware) Roof Slope Rafter Spacing Framing Type / Direction Wind Design Code Wind Design Method Basic Wind Speed V Fig. 6-1 Exposure Category Section 6.5.6.3 Roof Style Fig. 6-11B/C/D-14A/B Mean Roof Height h Section 6.2 Wind Pressure Exposure Kz Table 6-3 Topographic Factor Kzt Section 6.5.7 Wind Directionality Factor Kd Table 6-4 Importance Factor I Table 6-1 Ext. Pressure Coefficient (Up)GCp (Up)Fig. 6-11B/C/D-14A/B Ext. Pressure Coefficient (Down)GCp (Down)Fig. 6-11B/C/D-14A/B Design Wind Pressure p Equation 6-22 Wind Pressure Up p(up)Wind Pressure Down p(down) Y-Direction Max Allowable Standoff Spacing Landscape 39'' Max Allowable Cantilever Landscape NA Standoff Configuration Landscape Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR Y-Direction Max Allowable Standoff Spacing Portrait 65''Max Allowable Cantilever Portrait NAStandoff Configuration Portrait Max Standoff Tributary Area Trib PV Assembly Dead Load W-PV Net Wind Uplift at Standoff T-actual Uplift Capacity of Standoff T-allow Standoff Demand/Capacity DCR 22 sf 3.0 psf-315 lbs 500 lbs 63.1% 500 lbs56.9% X-Direction 48'' 17'' Staggered Staggered 20 sf 3.0 psf -284 lbs 14.6 psf ALLOWABLE STANDOFF SPACINGS X-Direction 72'' 0.88 p = qh (GCp) -15.8 psf 24'' qh qh = 0.00256 (Kz) (Kzt) (Kd) (V^2) (I)Equation 6-1516.7 psf Wind Pressure -0.95 Wind Pressure Calculation Coefficients 0.95 1.00 0.85 1.0 Velocity Pressure 25 ft Wind Design Criteria ASCE 7-05 Partially/Fully Enclosed Method 90 mph C Gable Roof Y-Y Rafters No Comp Mount Type C 45° 24'' O.C. CALCULATION OF DESIGN WIND LOADS - MP1C-UPPER Mounting Plane Information Comp Roof SolarCity SleekMount™