b"uniform wind loads (up).Wind Load Ratings of Roof Systems Asingle-plysystem used today is the mepopularroofRoof systemuplift resistancedeterminedFM Global windisby chanicallysystem. 'There is no atLachment ofroof fastenedLheandbeen for decades. If your building is insured by hasFM membrane to the roofLhe membrane is insulation. Typically,Global, youneed to follow their guidelines. All other will looselyandfastened to the deck with fas Leners in laiddirecllybuildingmay or maychoose to follow the FM wind o,vnersnot lapFiguredecklongerdesign protocol. Ita confusingotocol andnottly thescam, as shown in2. The roofis no ispr doesdirecuniformly loaded in wind uplift, as SDI assumed.relate to code specifiedsign wind needs. decondition citedRoofing manufacturers only provide FM rated systems. Using the example design windabove, we sec that12-ftsingle-ply membrane produces a line loadYour engineer has to male the specific conversion of wind load awide in uplift alongseparate profile ofdeck as shown. 1he atheloadpaths occurringand from mechanically fastened systemsthe is noL uniformly loadingdeck as shown in1. theFigureFM Global ratingthe roofing manufacturer. furnished by Example ofDeck Load Using a 6' Deck SpanAfter that exercise is completed, you may approve of the Total rooftoinstalledthe contractor. Your engineer Ifwe assume a 6-ft deck span, the follo.ving total loads persystembeby 6-ft also has tok thendpaths on the span occur:chec wi loadstructural elements supporting the steel roofattachment, Uniformly appliedatpsf-392deck and load21.8lbsamongdesign items. A factor ofeeds to be Uniform allowable per SDI atpsf-540othersafely also n30lbsconsidered. Line load from 12 ft wide sheet-1,572 lbs You need your engineer tothispattern and examineloadRene Dupuis, PhDofinvVl, can be reached PE,SRIMiddleton,at provide anload pathwind uplift resistance adequateforbecauseRDupuis@sri-engineering.com. Dupuis serves onMRCA's Technical thanperand the line load is three times greaterthe uniform load Research Committee. SDI. Carefully check the lineatjuncturethefull loadstheoflast widthperimeter,ithalf sheet near thewherejoins asheet. PROFILE: OF THEC RADIUS PAN ANO RADIUS PAN =SNA\\ ~ ,a1.DVARCJib ~ml'FE~ =-=- ~ ==-=-SHEETMETAL&SUPPLY -~~~-gg9231-861-0050~~ contractors for over 20 yearsinfo@advarchsm.com Now offering st anding seam roof pa nelsalong with our architectural brake metal,gutters&accessories, downspouts &elbows/ offsets. Curved panels also available. www.advarchs m.com Nationwide Shipping Available www.m rca.org- Midwest Roofer17"