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22B-026 (4) November 19,2018 QE To: Inspectional Services RECEIVED From: Paige Pereira—Trinity Solar 8Subject: Revised Engineer letter TION,060 Attached please the revised Engineer letter for 21 Corticelli St. If you have any questions, please don't hesitate to reach out. Thank you very much! Paige Pere a Paige.Pereira@trinitVsolarsVstems.com 413-203-9088 Ext. 1507 Trinity Solar 4 Open Square Suite 410 Holyoke, MA 01040 JOB NO.: U1982-0892-181 TSUBJECT: SOLAR LAYOUT r= n a i n F= F= R 8 PROJECT: Lindsay Slabich Residence A2 A? A6 As A4 F,, F_ 9 E C TO R JOB NO.: U1982-0892-181 Abbrev GRADES (psi) (psi) E.(psi) (Ib/R3) DFL#1 DFL#1 1,000 ISO 1,700,000 32 E it Q 1 M E E R 8 DFL#2 DFL#2 900 ISO 1,800,000 32 DF1 5X DFL#1 5X5&LARGER 1,350 170 1,800,000 32 SPF#2 SPF#2 875 135 1,400,000 26.2 SP#2 SP#2 1,100 175 1 1,400,000 34.3 PROJECT:Lindsay Slabich Residence SUBJECT:BEAMS 24F-V4 24F-V4 2,400 240 1,800,000 32 24F-V8 24F-V8 21400 240 1,800,000 40 DESIGN LVL 1.9 LVL 1.9X108E 2,800 285 1,900,000 40 Load Types: Snow Live Dead LVL(2.0) LVL(2.0X1 00E) 2,200 285 2,000,000 42 Roof 32 20 8 CRITERIA(L� D, Du DDL LSL LSL(1.3X108E) 1,700 400 1,300,000 42 Solar 3.5 A(BLANK) 120 240 STL36 GRADE 38 STEEL 21,000 14,400 29,000,000 490 B 240 480 STL46 GRADE 48 STEEL 27,700 18,500 29,000,000 490 C 600 800 STL50 GRADE 50 STEEL 30,000 20,000 29,000,000 490 Point Point o DLL DLL.I_ Add'I Add'I m Live Dead 0 (in) (in) 'Roof Floor Wall Live Solar Pant Dist Load Load at 3 A (SEE (SEE 1.5DL Length Trib Trib Trib Load Load Load > 'a' -PLi 'Poi = mW292 M,,,,,, M.1— V.- V,�„ DTL DTue— COND COND GLB Label 'L'(ft) (ft) (ft) (ft) (plf) (plf) From m (ft) (lb) (lb) m Grade Size A C, CO CF,v (ftIb) (ftIb) (Ib) (Ib) (in) (in) 'C') 'C') Camb Check Roof 3 5 2 7.0 1 SPF#2 2x4 1.15 1.15 1. 276 443 195 543 0.165 0.500 0.075 0.250 0.62 M Roof 1 10 0.68 2.4 1 SPF#2 2x4 rue 1.15 1.15 1. 374 514 140 828 0.451 1.000 0.204 0.500 0.73 M Roof 1 10 1.32 4.8 1 SPF#2 2X8 1.15 1.15 1. 729 948 265 854 0.451 1.000 0.204 0.500 0.77 M `Roof trib.adjusted based on the ratio of moment of Inertia. JOB NO.: U1982-0892-181 YE C TOR SUBJECT: GRAVITY LOADS E n O I n E E R S PROJECT: Lindsay Slabich Residence CALCULATE ESTIMATED GRAVITY LOADS Increase due to Original ROOF DEAD LOAD (D) pitch loading Roof Pitch/12 MONK Asphalt Shingles 2.6 1.31 2.0 psf 1/2" Plywood 1.3 1.31 1.0 psf Framing 3.0 psf Insulation 0.0 psf 1/2" Gypsum Clg. 0.0 psf M, E & Misc 0.0 psf DL 7 psf PV Array DL 4 psf ROOF LIVE LOAD (Lr) Existing Design Roof Live Load [psf] 20 ASCE 7-10, Table 4-1 Roof Live Load With PV Array [psf] w/Solar Panel SNOW LOAD (S): Existing Array Roof Slope [x:12]: Roof Slope [°]: 40 40 Snow Ground Load, p9 [psf]: ASCE 7-10, Section 7.2 Terrain Category: ASCE 7-10,Table 7-2 Exposure of Roof: ASCE 7-10,Table 7-2 Exposure Factor, Ce: 0.9 0.9 ASCE 7-10, Table 7-2 Thermal Factor, Ct: ASCE 7-10, Table 7-3 Risk Category: ASCE 7-10,Table 1.5-1 Importance Factor, Is: 1.0 1.0 ASCE 7-10, Table 1.5-2 Flat Roof Snow Load, pf[psfl: 35 35 ASCE 7-10, Equation 7.3-1 Minimum Roof Snow Load, pm [psfl: 0 0 ASCE 7-10, Section 7.3.4 Unobstructed Slippery Surface? ASCE 7-10, Section 7.4 Slope Factor Figure: Figure 7-2b Figure 7-2b ASCE 7-10, Section 7.4 Roof Slope Factor, Cs: 0.92 0.50 ASCE 7-10, Figure 7-2 Sloped Roof Snow Load, ps [psfl: 32 18 ASCE 7-10, Equation 7.4-1 Design Snow Load, S [psf]: 32 18 JOB NO.: U1982-0892-181 SUBJECT: CONNECTION E n a i n F= ER 8 PROJECTLindsay Sl3bichReedenme Lag Screw Connection Capacity: Demand: Lag Screw Size [in]: Pressure Max Max. Trib. Cd: NDS Table 2.3.2 (0.6 Wind) Tributary Area 2 Max. Uplift NDS Table 2 - Embedment I [in], (psf) Width (ft) (ft) Force(Ibs) Grade Zone Capacity[lbs/in] NDS Table 12.2A 1 16.1 16.5 266 Number of Screws 2 19.3 16.5 319 ,A Total Capacity[lbs]:l 586 Oemand< Cmpaobv: CONNECTION OKAY 1.Embedment is measured from the top of the framing member to the beginning of the tapered 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. I.'N1ax.TribArea'|sthe product ofthe'K8ax.Tributary Width'(along the rails)and 1/2the panel width/height (perpendicular tothe rai|s). JOB NO.: U1982-0892-181 TSUBJECT: WIND PRESSURE E n © 1 n E E R 3 PROJECT: Lindsay Slabich Residence Com onents and Cladding Wind Calculations Label: Note: Calculations per ASCE 7-10 SITE-SPECIFIC WIND PARAMETERS: Basic Wind Speed [mph]: 117 Notes: Exposure Category: C Risk Category: 11 ADDITIONAL INPUT&CALCULATIONS: Height of Roof, h [ft]: ��' (Approximate) Comp/Cladding Location: Enclosure Classification: Zone 1 GCP: Figure 30.4-2C (enter largest abs. value) Zone 2 GCP: (enter largest abs. value) Zone 3 GCP: (enter largest abs. value) a: 9.5 Table 26.9-1 zg [ft]: 900 Table 26.9-1 Kh: 0.90 Table 30.3-1 K,t: 1 Equation 26.8-1 Kd: 0.85 Table 26.6-1 Velocity Pressure, qh [psf]: 26.9 Equation 30.3-1 GCP;: 0 Table 26.11-1 (largest abs. value) OUTPUT: I p=qh GC,, — GCS,; Equation 30.9-1 Zone 1 Pressure, p[psf]: 26.9 psf(1.0 W, Interior Zones*) Zone 2 Pressure, p [psf]: 32.2 psf(1.0 W, End Zones*) Zone 3 Pressure, p [psf]: 32.2 psf(1.0 W, Corner Zones*within a) (a= 3 ft) VSE Project Number: U1982-0892-181 Lindsay Slabich Residence T11i13/2018 E n G i nr-= e R s The solar array 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 array to the existing roof against wind(uplift), the governing load case. Limitations 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 as-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 WEU L HOW" STRUCTURAL w No.641 Digitally signed by Wells Holmes Wells Holmes Date:2018.11.1316:39:38 111131201$ -07'00' Wells Holmes,S.E. MA License:54240-Expires:06/30/2020 Project Engineer Enclosures WLH/koc 651 W.Galena Park Blvd.,Ste. 101 f Draper, UT 84020 f T(801)990-1775/F(801)990-1776/www.vectorse.com .ZZ�o 02-'fo TOR E f'I O I f 1 E E R S VSE Project Number:U1982-0892-181 November 13,2018 Trinity Solar ATTENTION:Phil Smith 4 Open Square Way,Suite 410 Holyoke,MA 01040 REFERENCE: Lindsay Slabich Residence:21 Corticelli Street,Northampton,MA 01062 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 will require retrofit in order to support the proposed solar panel installation.The existing rafters of roof 1 must be retrofit by installing a new 2x6 the full length of the existing rafter.Install the new 2x6 rafter with 16d sinkers at 6"O.C.staggered.Roof 3 is permitted to remain unaltered. Design Parameters Code:Massachusetts State Residential Code(780 CMR Chapter 51,9th Edition(2015 IRC)) Risk Category:II Design wind speed: 117 mph (3-sec gust)per ASCE 7-10 Wind exposure category:C Ground snow load: 40 psf Existing Roof Structure Roof structure:true 2x4 rafters @ 24"O.C. Roofing material:asphalt shingles Roof slope:40° Connection to Roof 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 will require retrofit in order to support the proposed solar panel installation. The glass surface of the solar panels allows for a lower slope factor per ASCE 7, resulting in reduced design snow load on the panels. The attached calculations verify the adequacy of the roof to support the solar array after the aforementioned retrofit is complete. 651 W. Galena Park Blvd.,Ste. 101/Draper, UT 84020/T(801)990-1775/F(801)990-1776/www.vectorse.com