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of City & Borough Sitka Works Department Ptrblic of 113 JarvisStreet Sitka.AK 99835 Attn:ChrisVr'ilbur Pulp DocfiWarehcuse Re: Str4C Mr. \tVilbur: We havecompleted investigation the condition the SMC Pulp Dock\'VarehouseCur into our of investigation included sitevisitto the buridrng exarnination a numberci drawrngs a and uratyou of provided us. The;,Include (72-3-032833-32 72-3-032833-35). 11x':7 to four largedrawings to ten typicaldetails, sheetsof Builer's and six 8%x11sheetsof additional Butlertypicaldetails is The facility a Butlerpre-engineered metalbuilding originally constructed 1972. ll is 10C'x 480' in in planwrthan eave herght 28'. lt wasdesigned a 30 poundper squarefoot (pst) snow load of for and for the 20 psf wind loadpressure map. The structure consists rnetalroofCeckar-rd of wall panels sheathing between roofpuriins spanning and wall girts. The purlins and glrts span berween targeburlt-up framesat the intei'ior columnlines(20 feet on center)and beamsand steelmoment built-up steelwide iiangecoiumns theencjwalls. ihe cornershavetwo columns: at one ls a verticai loadbeartng flangesteelcolumn wtCe andtheotheris a lightgaugeC-shapeC windcoiunrn. Current Condition The rnain structurc the buiiding of to appcars bc in goncrally goodshapcbu: thcrcarc ntanv nrenrbers are showrng that significant deterioration. rust The main nronreni frar,-res travesorrre rusting apparent. is scaiebut uo n'la1or One oi the momenlframes has obviolrsly beenr.ltn inioas the flangenearthe baseis warped Theend rrlall colunrns, except lhe colners. at appear be irr lcl acceptable slrape.The cornercoiunrns showing are exiensive signsof rusi arrci severaic.'f Cine shapedcolurnns longerreachthe ground.fulost the purlins showing no cf are scme srgnsof cxiCization no nraicrrustlng.A fer.'pu:'lins predonrinately the ea\,9s. but at sno\r, so.r:le rna;orrus: delerioration. manycasesthe lowerfiangeis almosttotally ln gone. In others,majorsecttcns are gone. Sever:l of the wallgirtshavebeenreplaced and manyothershavemajorrust prcbrienrs. especially the corners al The foundation generallSr nord shapewrlha srngle is i6 typeof excepriorr. Several ihe concrete of column bascsalongtne Ccck siie havelostconcrete th:ough spalllng tf-te i'ebar expcsed anC toD rs
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anCccrrcded Unlessrepaired. piersrrillccntinue degradeand a catastrophic the to failurecculd Occur It is our understanding the roofing that has numerous leaks. The sidingalso has nunrerous holes iife. Theseare the main causesof and srgnsof majordamage. They are bothpasta reasonable waterinfiltration whichleadsto rustino lhe mernbers. of Desiqn Loads Currentdesignloadsare significantly different thanwhen this building was constructed.\Are have thedesignioadsbasedon the 1970UniformBuilding examined Code (UBC)and the 2003 International Building Code(lBC). Whilethe building codedoes not requirethata burlding be broughtup to current code.any new or replacement members haveto be designedfor current will cccjedesignforces. Snorvtoadswere not specifically called in tne 1970UBC but we believe out tharthe 30 psf for whrch was the standard Sitkaat that time. In the 2003 lBC, the groundsnow load for for tneydesigned Sitkais specified 50 psf. This results a roofsnow loadof 34 psf for this building in as basedon the (Cr=1.2), is of stanoa;"d factthatit is in an Exposure area(Cu=0.8), an unheated D is building and (l=1.0). rmportance The t970 UBC Wind-Pressure-Map Tablegives,for the 20psfzone,a designwind pr'ess'.rre Area of l5psfforbuildingsiessthan30'tall. lBC,thebuildingwouldbedesignedforal2O Underthe2003 gustwindspeed. Thiswind speedresults a typical(i.e..non-ccrner) mileper hour 3-second in designwind pressure 25 psf for the Exposure condilion of D witha mean roof heightof 30 feet. At the corners(i.e..within2A'ol a corner), wind pressure 38 psf. This is a significant the is increase rn wind pressure.In addition, current codetakesintoaccount rryind suction the roof. rryhere on the 1970codedid not. Sersmic loacshavealsosignfficantly rncreased. Underthe 1970UBC,the building woulC havelreen tJesigtred Seisrtrrc fol Zorre3 f<.lrces. designbaseshearwouldhavebeen .067Win tne The (mornent transverse (braced direction frames)and 0.10Win the longitudinaldirection frames). The seismic weight(W) wouldhaveincluded dead load (7 psf)only,as the 1970UBC did not the menlionsnowloadas partof the seismic weight. The allowable stressdesignbaseshearunderthe 2003 ltsCis .i46W in the transverse direction and .102Wrn the longitudinal direction.Theseioads are stgnificantly higherthanin 1970,especially whenone considers that W willconsrst the dead of loadand 2Oo/" the snowload (7 psf). The allowable of stressdesignbaseshearsfor the building wouldbe as follonrs: Direction Transverse Longitudinal
1970 UBC 24.8 kips 37.0 kips
2003 tBC 108kips 75.4kips
FrarneTvoe
Ordinary Moment Frame Ordinary Braced Frarne
Theseioadsare significantly lrigherthanthe criginal design. However, only new.replacement tneinbers haveto be designed the current will for loads. Any existing memberlhat we do not aller willbeacceplable is. as
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Re'commenCations We recommend that the following repairwork completed: be 1. Replace rustedgirts,purlins, and columns thatshowlossof material, opposedto all as purposes, haveassumedthat this includes purlinsat the merelyscale. For estimating we all wallto roofjuncture in and halfof the purlins the overhang, the wallgirts in the corner ail bays,and all the C-shaped at columns the corners.We estimate that this will cosl between and $75,000. $50,000 piersthat are showing 2. Repairthe tops of the concrete column spalling.We estimate that this vr,ill cost approximately $5000. the roofing 3 Replace existing andsiding, We estimate that replacing roofingwouldcost the bclwccnS3O0,0O0 $45O,000. and dcpcnding thc roofingsclcctcd. Rcplacing siding on thc wouldcost between depending the sidingselected.We on and $250,000, $175,000 retaining architect develop recommend an to this portion the project. of 4. We alsowouldrecomrnend the entirestructure a new paintjob. This wouldentail get that removing scalethat has developed applying new paintsyslem. We recornmend the and a retaining architect develop recomnrendation. an to this We notethat demolition the existing ot building construction a new buildlng and ol wouldcost approximately S2.5million Conclusion Whilethe main membersof the structure show somescale,they are in good conditionand only needa good coat of paint. However, thereare a numberof members.includingpurlins,girts. and wind columnsthat have beenseverelydamagedby rust and need to be replaced. The rust is due to waterin{iltration throughroofing and siding that is well pastits designlife and needsto be replaced. The only other work that needsto be doneis to repaira few concreteprersthat have lost concrete at theirtops. lf this work is completed the building properly and rs maintarned. shouldbe a useful it yearskl conre. fur structure lrrarry yours, Respectfully BBFMEngineers Inc.
Colin Maynard, PE Vice President
3 e n trrs L . Ber :) . r r
Far:crt T. Braun.P3
Troi J. Fcllcr. ?E
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