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HomeMy WebLinkAboutPV2019-101 - Calcsw2o1M 10 � Y 2 Z U Feet � Or ECTOR VSE Project Number: U1882-0708-191 August 2, 2019 l: ;VIII, orr:,:r .. --._. DL '� Il 61 bl (SIGNA FURL:) - Solar Permit Services, Inc. �s - -'---------___ ATTENTION: Nadir---- 2445Albany Ave. P�AwmraG -- Davis, CA 95618 BUILDING: APPROVAL TO ISSUE REFERENCE: Will Tipton Residence: 1226 Keel Drive, Newport Beach, CA 92625 DATE. Solar Array Installation To Whom It May Concern: Per your request, we have reviewed the existing structure at the above referenced site. The purpose of our review was to determine the adequacy of the existing structure to support the proposed installation of solar panels on the roof as shown on the panel layout plan. Based upon our review, we conclude that the existing structure is adequate to support the proposed solar panel installation. Desien Parameters Code: California Building Code, 2016 Edition (2015 IBQ Risk Category: II Design wind speed: 110 mph (3 -sec gust) per ASCE 7-10 Wind exposure category: C z m Existing Roof Structure Qin c: Roof structure: 2x4 rafters @ 24" O.C.ui [� r- vi Roofing material: Flat tile I Roof slope: 180 r Connection to Roof a �- i]] Mounting connection: (1) 5/16' lag screw w/ min. 2.5" embedment into framing at max. 72" O.C. along rails Conclusions Based upon our review, we conclude that the existing structure is adequate to support the proposed solar panel installation. In the area of the solar may, other live loads will not be present or will be greatly reduced (2016 CBC, Section 1607.12.5). The member forces in the area of the solar panels are not increased by more than 5%; thus, the stresses of the structural elements are not increased by more than 5%. Therefore, the requirements of Section 403.3 of the 2016 CEBC are met and the structure is permitted to remain unaltered. The solar may will be flush -mounted (no more than 6" above the roof surface) and parallel to the roof surface. Thus, we conclude that any additional wind loading on the structure related to the addition of the proposed solar array is negligible. The attached calculations verify the capacity of the connections of the solar may to the existing roof against wind (uplift), the governing load case. Regarding seismic loads, we conclude that any additional forces will be small. With an assumed roof dead load of 21 psf, solar array dead load of 3 psf, and affected roof area of 33% (maximum), the additional dead load (and consequential seismic load) will be 4.8%. This calculation conservatively neglects wall weight. Because the increase in lateral forces is less than 10%, this addition meets the requirements of the exception in Section 403.4 of the 2016 CEBC. Thus the existing lateral force resisting system is permitted to remain unaltered. 651 W. Galena Park Blvd., Ste. 101 / Draper, UT 84020 / T (801) 990-1775 / F (801) 990-1776 / www.vectorse.com Limitations VSE Project Number: U1882-0708-191 Will Tipton Residence 8/2/2019 Installation of the solar panels must be performed in accordance with manufacturer recommendations. All work performed must be in accordance with accepted industry -wide methods and applicable safety standards. The contractor shall notify Vector Structural Engineering, LLC should any damage, deterioration or discrepancies between the m -built condition of the structure and the condition described in this letter be found. Connections to existing roof framing must be staggered, except at array ends, so as not to overload any existing structural member. The use of solar panel support span tables provided by others is allowed only where the building type, site conditions, site-specific design parameters, and solar panel configuration match the description of the span tables. The design of the solar panel racking (mounts, rails, etc.), and electrical engineering is the responsibility of others. Waterproofing around the roof penetrations is the responsibility of others. Vector Structural Engineering assumes no responsibility for improper installation of the solar array. VECTOR STRUCTURAL ENGINEERING, LLC *v 7,r 0.;:..,. 0 l 08/02/2019 Russell Emery, P.E. CA License: C73566 - Expires: 12/31/2020 Project Engineer Enclosures RNE/ard 651 W. Galena Park Blvd., Ste. 101 / Draper, UT 84020 / T (801) 990-1775 / F (801) 990-1776 / www.vectorse.com JOB NO.: 07 E C T O R WIND SUBJECT: WIND PRESSURE E n G 1 Pl E E R S PROJECT: Will Tipton Residence Com onents and Cladding Wind Calculations Label: SITE-SPECIFIC WIND PARAMETERS: Note: Calculations per ASCE 7-10 Basic Wind Speed [mph]: 110 Notes: Exposure Category: C,='I Risk Category: II ADDITIONAL INPUT S CALCULATIONS: Height of Roof, h [ft]: Comp/Cladding Location: Enclosure Classification: Zone 1 GCP: Zone 2 GCP: Zone 3 GCP: a: Z9 [ft]: Kh: Figure 30.4-213 9.5 Table 26.9-1 900 Table 26.9-1 0.85 Table 30.3-1 Hip? Na (enter largest abs. value) (enter largest abs. value) (enter largest abs. value) Kn: 1 Equation 26.8-1 Kd: 0.85 Table 26.6-1 Velocity Pressure, qh [psf]: 22.4 Equation 30.3-1 GCP;: 0 Table 26.11-1 (largest abs. value) OUTPUT: p = qh [(GCP)— Equation 30.9-1 Zone 1 Pressure, p [psf]: 20.1 psf (1.0 W, Interior Zones') Zone 2 Pressure, p [psf]: 38.0 psf (1.0 W, End Zones) Zone 3 Pressure, p [psf]: 58.1 psf (1.0 W, Corner Zones' within a) (a= 3 ft) JOB NO.: U1882-0708-191 ECTOR SUBJECT: 7ECTORSUBJECT: SEISMIC LOADS E n G 1 n E E R S PROJECT: Will Tipton Residence COMPARE WIND & SEISMIC LOADS FOR CONNECTION (1 Sq. Ft. Section) Wind Load, W: Wind pressure, p , .-- psf (Zone 1 Height, h: 1.0 ft Width, w: 1.0 ft Fperp:l 12.1 Ib (Uplift) Seismic Load, E: Risk category: Seismic Design Category: Ip: Site Class: RP: Ss: Sj: ap: z: h: z/h: Fa: Fv: SMS: SM1: SDS: SD1: 0.6 W from wind pressure calculation) 0.7 * Fp,min: 0.7 * Fp,max: 0.7 * Fp,vert: 0.7 * Fp,long: 0.7*Fp,perp: CHECK INCREASE IN OVERALL SEISMIC LOADS SEISMIC: Estimated Roof Dead Load 21 Max. % of Roof w/ Panels Dead Load from Panels Total Dead Load 21.7 Increase in Dead Load 4.8% Wind Controls Connection Design 1.0 1.5 1.658 0.903 1.105 0.602 0.696 Ib 3.714 Ib 0.464 Ib 1.857 Ib 1.0154 Ib (uplift) psf 0/0 psf psf (DL+% of roof w/ Panels*Panel DL) Conservatively neglecting the weight of existing wall materials, the installation of the solar panels represents an increase in the total weight (and resulting seismic load) of 4.8%. Because the increase is less than 10%, this addition meets the requirements of the exception in Section 403.4 of the 2016 CEBC. Thus the existing structure is permitted to remain unaltered. Ul E O T O R JOB NO.: CONNECTION 1 SUBJECT: CONNECTION E r'1 G 1 n E E R S PROJECT: Will Tipton Residence Lag Screw Connection Capacity: Demand: Lag Screw Size [In]. '`5116` Ca 1.6 NDS Table 2.3.2 Pressure Max Max. Trib. z Max. Uplift (0.6 Wind) Tributary Area Embedment' [In] '2 (psf) Width (ft) (ftz) Force (lbs) Grade S�F_� *DAZ) Zone Capacity [lbs/In] ,.•F NDS Table 12.2A 1 12.1 60 16.5 199 Number of Screws `;1°:-- 2 22.8 B.O 16.5 376 Prying Coefficient: 1.4 3 34.9 &O 16.5 575 Total Capacity [lbs]: 586 Demand< Capacity: CONNECTION OKAY 1. Embedment is measured from the top of the framing member to the beginning of theta pered tip of the lag screw. Embedment in sheathing or other material is not effective. The length of the tapered tip is not part of the embedment length. 2. 'Max. Trib Area' is the product of the'Max. Tributary Width' (along the rails) and 1/2 the panel width/height (perpendicular to the rails). ECTOR E n G I n E E R S PROJECT: Will Tipton Residence CALCULATE ESTIMATED GRAVITY LOADS ROOF DEAD LOAD (D) Roof Pitch/12 33; Concrete Tile (Flat) 12.6 1/2" Plywood 1.1 Framing 3.0 Insulation 0.0 1/2" Gypsum Clg. 0.0 M, E & Misc 0.0 t 3 DL 17 PV Array DL 3 ROOF LIVE LOAD JOB NO.: U1882-0708-191 SUBJECT: GRAVITY LOADS Increase due to Original psf psf psf psf psf psf 1.05 12.0 psf 1.05 1.0 psf Existing Design Roof Live Load [psf] 20 ASCE 7-10, Table 4-1 Roof Live Load With PV Array [psf] 0 2016 CBC, Section 1607.12.5 w/ Solar Panel SNOW LOAD (S): Existing Array Roof Slope [x:12]:39 Roof Slope [°]: Snow Ground Load, p9 [psf]: Terrain Category: Exposure of Roof: Exposure Factor, Ce: Thermal Factor, Ct: Risk Category: Importance Factor, Is: Flat Roof Snow Load, pf [psf]: Minimum Roof Snow Load, pm [psf]: Unobstructed Slippery Surface? Slope Factor Figure: Roof Slope Factor, Cs: Sloped Roof Snow Load, ps [psf]: Design Snow Load, S [psf]: 3-9 ASCE 7-10, Section 7.2 ASCE 7-10, Table 7-2 ASCE 7-10, Table 7-2 ASCE 7-10, Table 7-2 ASCE 7-10, Table 7-3 ASCE 7-10, Table 1.5-1 ASCE 7-10, Table 1.5-2 ASCE 7-10, Equation 7.3-1 ASCE 7-10, Section 7.3.4 ASCE 7-10, Section 7.4 ASCE 7-10, Section 7.4 ASCE 7-10, Figure 7-2 ASCE 7-10, Equation 7.4-1 18 18 0 0 ; C FURY Exposed Fel ed 0.9 0.9 t 3 11 1.0 1.0 0 0 0 0 No Yes Figure 7-2b Figure 7-2b 1.00 0.87 0 0 0 0 C T O R LOAD JOB NO.: 070 SUBJECT: LOAD COMPARISON E n E 1 n E E R S PROJECT: Will Tipton Residence Summary of Loads Existing With PV Array D [psf] 17 20 Lr [psf] 20 0 S[ 0 0 Maximum Gravity Loads: Existing With PV Array (D + Lr) / Cd [psf] 29 22 ASCE 7-10, Section 2.4.1 (D + S) / Cd [psf] 19 22 ASCE 7-10, Section 2.4.1 (Cd = Load Duration Factor= 0.9 for D, 1.15 for S, and 1.25 for Lr) Maximum Gravity Load [psfl:1 29 1 22 Ratio Proposed Loading to Current Loading: 74% OK gravity loads in the area of the solar array are decreased; thus, the stresses of the aural elements are decreased. Therefore, the requirements of Section 403.3 of th i CEBC are met and the structure is permitted to remain unaltered.