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MSC <br /> ` ENGINEERS <br /> SINCE 1925 <br /> November 18,2021 <br /> Isaac Talley <br /> Technical Development Manager,Facilities&Operations <br /> Chemeketa Community College <br /> Re: 5000 Series Greenhouses-Salem Campus <br /> Structural Load Equivalency <br /> Isaac; <br /> This letter is intended to formalize recent resent discourse between yourself,our office and Chris Trussell, <br /> Building Official at Marion County. The topic involved how to translate the allowable design load <br /> capacity of the prefabricated greenhouse under risk category Ito appropriate allowable live load and wind <br /> load as a risk category II structure on a college campus. We proposed determining a mathematical <br /> equivalency of maximum ground snow load and 3-second wind gust speed. It would be incumbent upon <br /> the college to post visually prominent placards stating these limitations to occupancy and to accept the <br /> burden and liability to enforce these limits in perpetuity. Mr.Trussell acknowledged this methodology <br /> and recommended submitting an Alternate Material and Method Application. <br /> L For the benefit of those whom are not as familiar with the building code,these restrictions are being <br /> fit'' imposed upon these structures because they do not meet the design criteria prescribed for a risk <br /> occupancy II facility. Greenhouses are predominantly manufactured for agricultural operations which <br /> naturally are a lower risk category I facility and apparently are not manufactured for more onerous <br /> loadings. <br /> Note that these calculations and recommendations are only applicable to the 5000 series installed with <br /> both lower and upper wind bracing as depicted in the attached shop drawings.The college should be <br /> reminded that design snow and wind events exceeding these recommendations are plausible and feasibly <br /> would incur structural damage to the greenhouses. This is why the manufacturer recommends removing <br /> the covering in extreme events. <br /> Recommended maximum ground snow= 8" <br /> Recommended maximum 3-second wind gust=80mph • U • <br /> Sincerely, PaGPN4 t%7 <br /> -•••• cc 15,905 <br /> Douglas S.Meltzer,PE,SE EGON <br /> MSC Engineers,Inc. O � <br /> OG gy19,4g9ti1� <br /> 4<aS S.Mt\ <br /> Enclosure: Calculations&Shop Drawings IEXPIRkS: /Z-3r-zz <br /> CONSULTING STRUCTURAL ENGINEERS <br /> 3470 Pipebend Place NE,Suite 120 •Salem,OR 97301•Phone:503.399.1399•mscengineersinc.com <br />