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Permit 11/09/2004 09:26 FAX GROUP MACKENZIE Ej002 /008 :Gli I ' 1 \1 1 ' 49 W . CKEN IE .... ... \ Cr. fo v vv , . \..„, F ..•• • • O4 c ® ' ... • • November 8 20 • �+ , g v \\" m 0 v � 7- Eleven Inc. North Pacific Division 6— o Attention: Ryan Mitchell UA g Cascade East Centerpoint m 20819 72nd Avenue S., Suite 800 ›-ti e R o c Kent, WA 98032 p — 4 Q o LL ¢ • Re: 7- Eleven #25653 / 13285 SW Pacific Highway, Tigard, OR . d. a .c z m m Mechanical Unit Upgrade T. a ?•l= m Project Number 2040359.00 n 0 0 2 m Q ro co ° o re QU l id (/ i j 9 p a . Dear Ryan: " . at O w • On Tuesday, October 5, 2004, 1 performed a field observation of the above - captioned E structure to evaluate the structural feasibility of a proposed rooftop mechanical unit upgrade. o c n Y According to information rcccivcd from Kevin Royall of Source Refrigeration and 1- TVAC. 0. E two existing, very similar rooftop mechanical units, General Electric Model BTC048D300DO • rn and Model BWC048C300D1, weighing 517 pounds and :545 pounds respectively, are to he co replaced by two new units, Tranc Model YSC060A3RL weighing 522 pounds each. We 2 a assume that each unit will have a factory manufactured sheet -metal curb weighing approximately 70 pounds. We suppose that the adapters that arc usually used will not be - 0 • appropriate in this case, for reasons given below. It is understood that these are comprehensive operating weights. It is also understood that the "footprint" of the new units m • r and their placement on the roof will be essentially similar to the current arrangement. By copy M of this letter I ask that Kevin Royall inform me of any discrepancy with this understanding. 0 .0 0 This plan apparently results in an increase of approximately 10% in the weight of the units. However, this represents only about 1% of the distributed dead and snow Load tributary to the • joists supporting units, making the conservative assumption that only three joists participate. Group This being the case, the performance of the framing is expected to be entirely unaltered. On Mackenzie. the other hand, there is no evidence of special provisions in the design for support of the Incorporated mechanical units, such as the double trusses usually seen, and the joists may be overstressed at present. Probably, the design incorporates reserve capacity in all ofthe misses, allowing for complete flexibility in the placement of the units. Framing plans that might confirm this are unavailable however; neither the City of Tigard nor 7- Eleven were able to locate design Group documents in their archives. Machcnzic Engineering. Incorporated Given this lack of certainty, we recommend demolition of the existing timber curbs beneath ._,v;.,;;,r „c,,,r,,, the units and substitution of new timber curbs with a revised geometry capable of distributing ^' the weight of the units over a larger number of joists. Since the old curbs are to be replaced, ir ;ponuo„ use of an adapter seems unnecessary; the new timber curbs can be sized for a standard slice': `iduHi "y metal curb. A drawing showing the proposed arrangement is attached. Locations. Nu, ILinc.i, Lbuyon 7,,,)n1.,, W,:ltn,inn H: \PROJ FCTS \204035900 \W P \041108 -L.I ,da- 11/09/2009 09:26 FAX GROUP MACKENZIE 11003 /008 • �i- 7-Eleven Inc. North Pacific Division 7- Eleven #25653 / 13285 SW Pacific Highway, Tigard, OR Project Number. 2040359.00 November 8, 2004 Page 2 The new units should be installed in accordance with the manufacturer's recommendations. In the absence of any other specific instruction, attachment of the units to thc adapters and of the adapters to the supporting timber curbs should be as described in thc attached calculations. For attachment to the supporting wood curbs, the contractor may substitute 3/8" diameter lag screws, with 3" of embedment into thc wood, for the proprietary fasteners mentioned. Fasteners should be uniformly distributed around the perimeter of each unit's adapter. My cursory observation disclosed no evidence of structural degradation due to rot in the timber structure, nor any other condition that would cause concern. On the other hand, my field of view was restricted, and my observations should not be thought of as comprehensive by any means. As is usually the case, problems may exist in construction hidden from view. No excessive deflection was observed. in summary, we feel that replacing the existing timber curbs with new curbs capable of better load distribution is a practical and responsible step given the increase in load and the lack of information about the capacity of the existing framing. We hope you find this satisfactory. Please call if you require additional information. Sincerely, : • _ • Thomas 8. Higgins, S.E. Structural Engineer ti ; TRH /mpd - - -- c: Kevin Royall Source Refrigeration and HVAC I I:'.PRO.1 7rS \204035900\wP\041 I OS- L1.doc 11/09/2004 09:27 FAX GROLiP MACKENZIE al004 /008 - II 0 11 ©11 011 011 0 10 11 0 II I 11 11 11 11 11 11 3)l TYP. 1■•■11 11 0 II 1)1 `` x '11 1, ' 11 11 11 II 11 11 0 IUD �I �' .. __J III 011 II 11 11 \ II — ,71 1 1 11 11 11 O jam \ 0 11 II II II II I II II II 11 ,Il 11 11 Qi 110 110 II KEYNOTES A. EXISTING LIGHT METAL PLATE: CONNECTED WOOD ROOF TRUSSES. B. NEW MECHANICAL UNIT WITH STANDARD METAL CURB LOCATED OVER EXISTING ROOF PENETRATION. C. EXISTING ROOF PENETRATION - NOT TO SCALE. D. NEW MINIMUM 4X8 DF -L CURB PIECES ATOP ROOF SUPPORTING LONG SIDES OF NEW UNIT. EXTEND ENDS OF PIECES TO SPAN OVER EIGHT ROOF TRUSSES AS SHOWN. PIECES MAY BE TAPERED AND SLOPED AS NECESSARY TO CREATE LEVEL BEARING FOR UNIT. MAINTAIN MINIMIM PROFILE EQUIVALENT TO A 4X6. E. NEW MINIMUM 4X8 DF -L CURB PIECES ATOP ROOF SUPPORTING SHORT SIDES OF NEW UNIT. TAPER AND SLOPE AS NECESSARY. F. (2) 3/8" X 6" LAG BOLTS WITH WASHERS 3" ON CENTER VERTICALLY IN 1" DIAMETER X )¢" DEEP COUNTERBORED HOLES AT EACH CONNECTION. G. (16) SIMPSON THA413 ADJUSTABLE TRUSS HANGERS INVERTED OVER 4X8 CURB PIECES. EXTEND STRAPS THROUGH SLOTS IN SHEATHING TO SIDES OF ROOF TRUSSES. INSTALL (4) 10d FACE NAILS INTO JOIST TOP CHORDS AND (4) 10d NAILS INTO 4X8 AT EACH HANGER. H. CANT STRIPS AROUND TIMBERS. TIMBER CURB PIECES AND CANT STRIPS ARE TO RE ENTIRELY ROOFED OVER. ROOFING DESIGN BY OTHERS. .c itUC /? C4" 4191 � G INE, / X 15 „ , A ice. � o :: ON ►1 V s 9. Ht' EXPIRES: 6 14705 G 11,0 U P A �( 7 PROJECT: DATE: SHEET: C 1� E N Z I E1 TI ARD 1 UPGRADE PACIFIC HIGHWAY 11 /5/2004 DRAWN BY: TBH 1 CHECKED BY: Portland OR Venoouvor WA Tacoma WA Beadle WA, TBH 603.224.8660 960.806.7870 269A710681 208340.0008 SHEET TITLE - -.. . -. . - = TIMBER CURB AND MECHANICAL UNIT PLAN ® rda,o id.aoau 7m. Au. mom; PGEWEP JOB NO: TM V� ° 10 uva w Y UMNOI0. m E T ' PPRI M rn ' iT T T ` POWC I o APPROXIMATE SCALE: 1/2' - T -0' 2040359.00 11/09/2004 09:27 FAX GROUP MACKENZIE EJ005 /008 G R O U P I 0890 SW BANCROFT STREET - P.O. BOX 6903E PORTLAND, OREGON 97239 -0039 �► Z I E TEL (503) 224-9560 - FAX (503) 228.1285 GENERAL CALCULATIONS PROJECT NAME: 7- Eleven #25653 / 13285 SW Pacific PROJECT NO.: 2040359.00 DATE: 11/5/2004 Hwy., Tigard, OR, Mechanical Unit Upgrade ELEMENT ID: Rooftop Unit Weight Analysis DESIGNER: TH Wnew units 2•(522.1bf + 70 -lbf) Wnew units = 11841bf Wold units := 517•Ibf + 545 Wotd unit:: = 10621bf units Wnew units — Wold units Aunits = 122 Ibf A units = 11.5% Wold units Wroofdcad 14- psf- (6- $- 39- 458•ft) Wroofdcad = 3314.5lbf Wroof snow 25-psf -(641.39..458-ft) Wroof snow = 5918.7 lbf A units = 1.19% Wold units + Wroofdcad + Wrr of snow psf - lbf ft 2 11/09/2004 09:27 FAX GROUP MACKENZIE 006/008 G'R 0 1j P — 0690 SW BANCROFT STREET • P.O. BOX 69039 w...<.. A C K E N Z I E I PORTLAND, OREGON 97239 -0039 TEL (503) 224 -9560 - FAX (503) 228 -1285 MECHANICAL UNIT ATTACHMENT PROJECT NAME: 7- Eleven #25653 / 13285 SW Pacific PROJECT NO.: 2040359.00DATE: 11/5/2004 Hwy., Tigard, OFt, Mechanical Unit Upgrade ELEMENT ID: Mechanical unit attachment at roof DESIGNER: TH Assumptions: • Weight of mechanical unit, with curb, W _= 522•lbf + 70.1bf. • Height of unit above top of curb, h := 32.25•in - Height of metal curb supporting unit, h := 14.0.in. • Location of mass centroid of unit is assumed not higher than 2/3 of the height of the unit above the top of the metal curb supporting unit. • Narrow dimension of base of uiit at fastener lines, b„ := 44.25 -in - 2•in, from centerline of bearing flange to centerline of bearing flange. • Narrow dimension of curb, from centerline of fastener to centerline of fastener at attachment to supporting wood structure, b := 44.25in. • For unit -to -steel curb attachment use 12 -14 x 1 1/4" Scots fasteners with stainless steel encapsulated hex washer head and ##2 point by ITW Buildex. Quantity N := 4. (Quantity chosen should be evenly divisible by 4.) Total thickness to be drilled and tapped must be not over 0.210 inch. Fasteners are to be located at unit comers. Any additional fasteners shall be uniformly distributed around the perimeter. • See ITW Buildex Product Catalog 2003, page 20 for fastener capacity information. Steel curb and unit flange construction is assumed to be 18 gage steel or thicker. On this basis ultimate shear and tension capacity of the screws attaching the unit to the metal curb are, respectively, V := 2138•lbf, and T := 1181•lbf • For steel curb -to -wood curb attachment use 9 -15 x 2 1/2" Trugrip fasteners with hex washer head by ITW Buildex through pre - drilled holes in metal flange of curb. Root diameter, D := 0.122•in. Quantity N := 8. (Quantity chosen should be evenly divisible by 4.) Fasteners are to be located at curb corners. Any additional fasteners shall be uniformly distributed around the perimeter. It is assumed that roofing materials will afford protection to the heads of these fasteners. If this is not the case, equivalent Scots Trugrip fasteners with stainless steel encapsulated hex washer head should be substituted. • See ITW Buildex Product Catalog 2003, page 24 for fastener capacity information. Embedment of Trugrip fastener in wood is assumed to be not less than 1 1/2" and steel curb flange construction is assumed to be at least 18 gage steel with minimum thickness, i := 0.048•in. Wood curb is assumed to be sound Douglas Fir -Larch capable of resisting the required loads. Evidence of rot or substandard construction should be reported to the engineer. Tension capacity is governed by lesser of fastener tension value, pullout in wood and unwashered pullover in steel flange. Pullout in steel is not applicable. Allowable shear capacity is governed by lesser of fastener ultimate shear value divided by the factor of safety and shear value in wood per 1997 NDS calculated below. On this basis ultimate shear and tension capacity of the screws attaching the steel curb to the existing wood curb are, respectively, V 1200•lbf, and T := 872•lbf. • Structure roof elevation and uni attachment elevation are, respectively, h 14.5.ft, and h := 14.5.ft • Structure is in Seismic Zone 3 and soil type is assumed to be S so seismic coefficient, C := 0.36. • A factor of safety, FS := 5, against working loads is used. • A linear shear /tension interaction is conservatively used • The importance factor, 1 := 1.0. • Per Table 1997 UBC 16 -0 for mechanical equipment, horizontal force factors, a := 1.0 and R Attachment.xmcd ATTACHMENT -1 11/8/2004 11/09/2004 09:27 FAX GROUP MACKENZIE V1007/008 LATERAL FORCE FUNCTION PER SECTION 1632.2: ap C I h F C I R h h W := C1 4-- 1 + 3 - R h p r C7 + 0.7 -C I C3 4- 4•C CF- C2 if CI <_C2 C3 if CI C3 C othcrwisc / C.SN p Fplap, Ca,Tp,Rp,hx,hr,Wp) F = 2841bf Check unit -to -steel curb attachment. Consider overturning about longer edge of unit. Fp Ns = 71.01bf 5 2 • - •h Fp • 3 1i= T = 72.31bf N 5 +1 bu 4 V + T _ 0.472 Less than 1.0, OK. V, T, FS FS Attachment.xmcd ATTACHMENT -2 11/8/2004 11/09/2004 09:28 FAX GROUP MACKENZIE Z008/008 Allowable shear in wood -to metal connection per 1997 NDS Section 11.3.2: F 4650•psi Per 1997 NDS Table 1 IA for Douglas Fir -Larch F := 90000•psi Value as assumed in 1997 NDS Table 11.3A F := 45000.psi Value as assumed in 1997 NDS Table 11.3A F R :_ — R = 0.103 Fes 2 k:_ –1 + 241 + R + F -(2 + Re)•D k = 11.363 Re 2 'FCm'ts 2 KD := 2.2 if D 5 0.17 -in KD = 2.2 10 D + 0.5 if 0.17•in <D <025.in in 3.0 if D 0.25.in k D•ts Z := Z1 , = 66.9 lbf Kfl•t2 + R. D i 1 Fem'Fyb Z2 - - -. KD 3.0 + Ro Z if71 <Z2 - Z2 otherwise V Vallow Z if Z < FS Vallow = 66.9 lbf V — otherwise FS Check steel curb -to -wood curb attachment. Consider overturning about longer edge of unit. F V N := P V = 35.5 Ibf w 2 F P 3 3 •hu +he = T = 76.0 lbf N b — +I 4 V + T = 0 . 9 67 Less than 1.0, OK. Vallow Tw FS Attachment.xmcd ATTACHMENT -3 11/8/2004 .slkr: a� 6. M I rt 1 7 A A (i ieights Table W1 — Maximum Unit And Comer Weights (Lbs)And Center Of Gravity Dimensions (In.) Unit Maximum Weights (Lbs) Comer Weights (Lbs)1 Center of Gravity (In.) Tons Model No. Shipping - Net A B C D Length Width 3 YSCO36A 534 480 151 124 96 109 32 19 YHCO36A 551 497 158 128 101 110 32 19 4 YSC048A 559 505 159 130 108 109 33 19 YHC048A 593 539 166 133 114 126 32 20 5 YSC060A 576 522 169 134 105 114 32 18 YHC060A 628 574 179 140 119 136 32 20 NOTE 1. Corner weights are given for information only 2. Weights are approximate CENTER OF GRAVITY LENGTH A CENTER OF GRAVITY WIDTH • c D C CENTER OF GRAVITY Table W -2 — 3 - 5 Ton Factory- installed Options Net Weights (Lbs) Accessory Weight Economizer 26 Barometric Relief 7 Motorized Outside Air Damper 20 Manual Outside Air Damper 16 Roof Curb 70 Oversized Motor 5 Belt Drive Motor 31 Smoke Detector, Return 7 Smoke Detector, Supply 5 Coil Guards 12 Hinged Doors 10 Powered Convenience Outlet 38 Through the Base Electrical 8 Through the Base Gas 5 Unit Mounted Circuit Breaker 5 Unit Mounted Disconnect 5 Novar Control 8 NOTES Weights for options riot hsteo are >5 lbs 2 Net weight ShOrrIO be added to unit weight when ordering factory- instaired accessories RT- PRC006 -EN 45 I • A Ctl. i : rt. 1 L d '� 1 , l t .1 r ti MAIL ,„, 1r( .,,, oe mensa®E ;all `Ij . k,i •, p. rP. AAw ag aki .11w1G?'kviiL4!7;r∎PgRmT.. (Bdb..,.'rAih'Ci C ,IIRtn erni + :.4.klifaiO4,6A. ^Jd0g.7.0A.nt 9k:klo-;er,f.T,, rw ilKide.a .d. +11,,,mi i. 094:1 1 All dimensions are in inches /millimeters. 3, 4, and 5 Ton Standard Efficiency — Low and Medium Heat (without Novar Controls) I 3 and 4Ton High Efficiency — Low and Medium Heat (without Novar Controls) TOP PANEL EVAPORATOR SECTION ACCESS PANEL 1 CONDENSER FAN 41 '�¢ -.�_ X_ - 321/4' 41/4 819 MM 108 MM CONDENSATE DRAIN 3/4 - 14 NPT DIA. HOLE r; %� I�!� CONDENSER COIL • / 1 ' UNIT CONTROL WIRE ' 239/16' a o!I 598 MM __SERVICE GAUGE PORT ACCESS \ �� \ 1::./ 41101! 48M 1 3/8' (35MM) DIA. HOLE 42 1/4' ,' 69 7/8' 1073 MM ':�' 10M• 1749 MM 5 9/16' UNIT POWER WIRE 1 l 141 MM 1 3/32' (28MM) DIA. HOLE u 5 5/8" 7 5/8' 143 MM - 194 MM — 94 5/8' 44 1/4' 244 MM 1124 MM 1/2 NPT GAS CONNECTION --I 3, 4, and 5 Ton Standard Efficient —High Heat CONTROL AND COMPRESSOR y — g ACCESS PANEL ;_ 3 and 4 Ton High Efficiency — High Heat 5Ton — High Efficiency — Low, Medium, and High Heat All3 through 5Ton with Novar Controls TOP PANEL EVAPORATOR SECTION ACCESS PANEL O CONDENSER FAN / `,,, ' -.:- =^" _.^: ".- 4., . i 921 MM 4 1/4' 108 MM CONDENSATE DRAIN �� 3/4 - 14 NPT DIA. HOLE I LO 1 �'� j / �� CONDENSER COIL / UNIT CONTROL WIRE ^ � A e . ® • �/ 7/8' (22MM) DIA. HOLE +\ 239/16' �\ 514M p / � 598 MM 1111 SERVICE GAUGE PORT ACCESS \ 1*-1. _0r/ 1318' (35MM) DIA. HOLE 421/4' - •:r 41/4' 69 7/8' 1073 MM !i 108MM• 1749 MM UNIT POWER WIRE 5 9/16' 1 3/32' (28MM) DIA. HOLE 141 MM Y'(�� I � / L 5 5/8' ° 7 B' L'' � 143 MM X194 MMM� I _ 9 244 M 5/8' M 44 1/4' 1124 MM 1l2 NPT GAS CONNECTION —/ / -- CONTROL AND COMPRESSOR ACCESS PANEL RT- PRC006 -EN 41