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Correspondence 09/20/2004 MON 9:28 FAX 15032808866 PRC Inc. y_ 11002 /006 /6/..3a / s 4.,/ . ��2us ifr e 09/1'7/204 _ 0Q: 49 • 503- 443 -3700 TM RIf'PEY PAGE 07. • • 7650 SW 13eveland Street, Suite 100 TM RIPPEY • Tigard, OR 97223 � 1 CONSUI,T1NG ENGINEERS Phone: (503) 443 -3900 Fax: (503) 443 -3700 • September 16, 2004 Professional Roof Consultants • Attention: Steven McBride 4035 NE Sandy Blvd., Suite 212 Portland, Oregon 97212 • Re: Scholls Business Center. - Bui.Iding N and P Re -roof Project Number: 4318 Dear Steven: The following Ietter is with regards to the re- roofing of Buildings N and P at the property listed above, and the ability of the existing roof structure to support the addition of a new roof without the removal of the existing roof. From information provided by Steven McBride at Professional Roof Consultants, Inc., it was assumed that the new roofing to be added weighs approximately 2.5 psf, while the existing roofing weighs approximately 2.0 pat*. The existing roof structure in both buildings is typically comprised of 2 x 4 subpurlins spaced at 2' -0" on center, supported by purlins spaced at 8' -0" on center, which are supported by glu -lam beams and steel columns. Based on our observations and the original building drawings we determined that there are three purlin types: 1. 20' -0" span -4x 14 DP #1. 2. 22' -6" and 25' -0" spans.— original drawings specify three wood type options for 4 x 16 purlins: HF Select Structural, DF #1, and DF Select Structural. Through grade stamp observation we have determined that they are DF #1. 3. 30' -0" span ••- glu -lain 3 1/8 x 16 1/2 (in Building N only). The typical dead load demand to any purlin with the new roof added is approximately 10 psf (excluding purlin weight), and per the current building code the minimum snow load demand is 25 psf. Thus, for an existing .purlin to meet current code requirements with a new roof, it must be able to support a total applied load of 35 psf. • • • • 09/20/2004 MON 9:28 FAX 15032808866 PRC Inc. 2003/006 @9/17/2004_ 09:49 503 -443 -::700 TM RIPPEY PAGE 03 SchoIls Business Center - Building N and P Re -roof Project Number: 4318 September 16, 2004 Page 2 Based on our calculations, the 4 x 16 purlins that span 25' are not adequate for support of the required loads. Based on these results, it is our recommendation that the existing roofing be removed at these locations (see included plans) prior to the installation of the new roofing. All other purlin types are sufficient to support the new roofing without removing the existing roofing. It should also be noted 'that the effects of existing mechanical units were not taken into account when calculating the capacities of the existing roof members. Additionally, several tenants in Building N complained of leaking problems. The areas of these leaks were observed (see plans for approximate locations) and there was no apparent damage to the roof members, only water staining. Due to the limited nature of the available information and the method of inspection, it should not be construed that this assessment specifically describes in detail every location on the roof of this building, nor does it address any hidden conditions that may be obscured by existing finishes. Rather, it is a general assessment of the strength of the roof structure. If you have any further questions, please do riot hesitate to contact our office. Sincerely, Ralph Twmbaugh, P.E. Principal RT /mdg 11utw , # 0020 1? • OREGON §F3 ,� r/ R cp H TUR�$a�� D8 I DS • _ 43 AREA O \ AREA 82 1- EC�ENp O \ AR BI \ O SDS NEW THROUGH WALL a SCUPPER DRAIN WITH DOLLN SPOUT . SDS 0 Off\ SDS SDS SDS 0 OA SDS lo os S P U GUTTER WITH DouN • ® A ® / / H ® ® H 0 H P ANT ® A 0 © EXIST. CURBED HVAC • C / \ \ O/ 1 \ / • O \ / O \ . O I SK TLI HT� ® 0 0 AND INFILL DECK f' W " EXIST. CURSED EXHAUST W I• W W _ _ W : :: 1r 1 VENT Lai ® Q ' 0 Q r Q i 3 / E% . G ® I__1 . . y I. M P I r O : A w P SIM.O ® ACCESS HA © > > i P > I M Q 3 , ,, . ) O I 3� Q 0 0 ® ABANDONED G E • III MP ' 0 > 7l PENETRATION - L • _ G E - REMOVE AND PROVIDE Q l:© E .G O � _ • E•. QI ( O 16 GA. GALV. STEEL • 0 Ell µ J A A M •'I ®H PLATE OVER OPENING o IA © 4 • G I I I i ,...ZIP EXIST. MULT. PIPE �p I`'I PENETRA G ( E© O Q ,O 3 O J ® I I ® }. EXIST. SATELITE DISH - '. r Ill 4 } 3 S O SET ON NEW WALK PAD - - - - - --� , 3 .E ®• 0 O0H EXIST. HOT EXHAUST H AREA C3 J © E ® H G © 2C .- " --- AREA C5 O P EXIST PIPE VENT • SIr-0 (NIC) 0SiM. AREA O E EXIST. ELECTRICAL 0 M. AREA G2 • — SIM. Q PENETRATION - MODIFY ab (NIC) EA C4 0 WHERE DIRECTED NIC) O r, EXIST. NATURAL GAS AREA CI (NIC) 6 ,.. EWH RE DIR `/ �) 7L i/>.' 7 KG s Hou BUSINESS N CENTER •S')(y l2C!/ R p l SUILDING N - ROOF PLAN N BLDG. N & PROOF REPLACEMENT SCALE: I" • 20' -0" PORTLAND OREGON .\ -ate: 08/31/0- REVISED new KEY NOTES i - ; . , O minimum Existing 8inchver ticall h pe g eight, and reconnect d i n wtlh le cable through new 1-1/2 indt�rigid conduit Re-route on eq� O Ong yysttee over c flashing and fan s unk curb. Install new traffic SLM flashing. with new PVC weatherhead. Reference drawing to for si counter flashing weather lapped with existing cap fleshing. D - • INGS flashing condition. fa Existing natural gas line penetration through roof. Disconnect, Existing abandoned curb to remain. Provide new cap flashing Installed extend piping vertically as required to install proper lead flashing, /7\ Existing mechanical units mounted to sleeper curbs. Re-use O over new self- adhering undertayment. and reconnect. Reference drawing existing curb cap fleshings. Trim existing APP membrane flush with bottom of existing cap flashing hem and weather lap new Q Existing exhaust duct to remain. Install new p.L wood curb around O Existing flex conduit penetration through roof. Disconnect end counter flashing with existing membrane and cap flashing. .base of duct and provide new surface- mounted counter flashing set In DRAWING provide new rigid conduit penetration through roof with lead sealant tape over surface of duct, extending over new curb. flashing. Reconnect unit with flex conduit from unit to rigid O J existing sle eper curbs where separated. Utilized wood d% conduit. Reference drawing Oµ fram to allow for co bas fl ashin g I and O Existing antenna penetration through abandoned lead pipe flashing. o e provide sheet metal saddle fleshings at curb offset transitions. Retain existing antenna securement and provide new IAad flashing and PI SSIONAL P O Existi ng e xhaust provide flue pen R cap eferan drawing nsT for stoml collar. ROOF Job. fleshing - new weather n iht and duct axle on O Existin abandoned sleeper curbs to remain. Remove e g g xisting penetrate e Existing rigid conduit through base flashing. Disconnect conduit set- adheringaunderlayrnennt�de new cep fleshings set over new O � reme�ag nspe undersideend mdify anchorage of Interior deck. to R221:621 O and relocate conduit pen on minimum 12- Inches from unit suspended equipment. relocate all structural attachm nt Into exist 0� curb. Reference drawing µ • puffins / Joists. 2H7�Kl / �/ • r