b'TECHNOLOGIEConception du systmeDeux conceptions de systmes de pare-neige sont assez courantes. La premire utilise des lments horizontaux continus, assembls latralementtravers le toit dans le style duneclture . Ces assemblages sont habituelle-ment installs prs de lavant-toit ou directement dessus. On peut aussi les rpter en rangs parallles en remontant la pente du toit, mais avec une plus grande concentration prs de lavant-toit.Figure 3 Lautreconceptionconsisteendepetitesunits A fence (continuous) type snow guard;discontinues utilises commetasseaux , gnralement A cleat (discontinuous) type snow guard Figure 3 localises ponctuellementlavant-toit ou prs de celui-ci, Un pare-neige de typebarrire(continu) ou rptes selon un motif progressant le long de la pente Un pare-neige de typetasseaux(discontinu) du toit. Ce style sappuie galement sur la rsistance au System Design cisaillement dun banc de neige pourfaire le pontentre Twosnowguardsystemdesignsarequitecommon.Oneles units individuelles.utilizes continuous horizontal components, assembled laterallyLes deux styles de dispositifs de protection contre la across the roof in the style of a fence. Such assemblies areneige (cltures et tasseaux) ont dmontr un rendement usually installed at or near the eaves. Depending on specificsatisfaisant lors de lessai, de lingnierie et de linstallation job conditions and load-to-failure characteristics of the devices,approprie. (Figure 3)they may also be repeated in parallel rows up the slope of theTechniques de rtention de la neigeroof, but with greater concentration near the eave area.Troistechniquespermettentdeposerdespare-neige The other design consists of small, discontinuous individual units used as cleats, generally spot-located at or near thesurunecouvertureenmtal:deuxutilisentdespare-eave or repeated in a pattern progressing up the slope of theneige fixs mcaniquement. La distinction entre les deux roof, again with a greater concentration near the eaves. Thisimplique le serrage, qui saisit le joint debout dune manire style also relies upon the shear strength within a snowbank toouduneautresansrellementpercerlematriaudu bridge between the individual units. panneau (non pntrant) par rapportla fixation de visBothstylesofsnowguards(fenceandcleat)havetravers le matriau du toit (pntrant). La troisime utilise demonstrated satisfactory performance when tested, engineeredune mthode chimiquement attache, qui consistecoller and installed properly and adequately. (Figure 3) des pare-neigela surface.1) Fixation dun pare-neige sur un toitjoint debout : Snow retention techniques Cette mthode utilise un systme de pinces agrippant Therearethreetechniquesformountingsnowretentionles joints debout. Les pinces se fixent directement sur systems to a metal roof. Two use mechanically attached snowle jointlaide de vis sans tte qui ne pntrent pas guards. The distinction between the two involves clamping,dans le toit (mcaniquementfix (Figure 4).which grips the standing seam in some fashionwithoutactuallypuncturing thepanelmaterial(non-penetrating) vs.fasteningscrewsthroughthe roofmaterial(penetrating)intothe structure. The third uses a chemically attached stick-on adhesion method, which involves gluing individual snow guards to a roof surface.1) Clampingasnowguardtoastandingseamtyperoof:This methodusesaseam-clamping attachment and is a secure optionFigure 4forastandingseammetalroofMechanical clamp attachment with round profile when proper certified testingpoint setscrews is advocated by MCA, andengineeringisemployed.MBMA and USDODClamps attach directly to the roofFigure 4seamusingsetscrewsthatdonotLa MCA, MBMA et USDOD prconisent penetratetheroof(mechanically- lutilisation dattaches mcaniques avec attached) (Figure 4). des vis de rglagepointe ronde.AUTOMNE/HIVER 2021 COUVERTURES CANADA 39'