b'ARCHITECTURAL SHEET METALto expand with the panel. water diverter must be applied to divert water channeled Ridge Assemblies from the metal panels away from the curb.Standing seam metal roof panels are typically fastenedEnd Wall Transitionsat the eave, which creates thermal movement thatIn instances where metal roof systems are installed accumulates at the ridge. Openings that occur from thison structures that have parapet or adjoining walls a type of movement are eliminated with the design of metaltwo-piece flashing is used for the parallel transition. In ridge covers that are attached to the metal panels. Thethis detail the metal base flashing assembly is secured metal ridge covers should be designed to accommodatedirectly to the parallel metal panel and set freely up the movement and flex as the panels expand and contract.wall. The base flashing becomes part of the metal panel The panel closures serve as weatherproofing protectionand moves with the panel. A metal counter flashing is andwhen professionally installedeliminate moisturesecured to the wall and covers the base flashing. The intrusion. independence of the two Penetrations flashing materials allows Thedesignershouldfor appropriate expansion alwaysspecifyand contraction.penetrationmaterialsSomemanufacturers provided by the metalrequiretheuseof systemmanufacturernonmetallic membranes andstatethattheseat high side transitions. materialsshouldbeThese flexible membrane applied in accordancematerials are applied to with the manufacturersthe top of the metal panel requirements.Theclosure and are secured most important materialtotheperpendicular component is the designwall.Theflexible ofproperadhesives.membranes are typically Asphalt based adhesivesmanufacturedwitha and cutbacks are typically not compatible with metalmetallic apron flashing that provides added moisture systems and should be avoided even in emergencyprotection and accommodates foot traffic. These types repair situations. Consult the manufacturer for theof materials are also considered to act as air seals.design guidelines of the proper repair materials. MostThe proper design of materials at these vulnerable points manufacturers allow the use of rubber bootjacks for allwill eliminate moisture intrusion leading to a satisfied round penetrations eliminating the application of pitchclient and a successful project.pans. It is critical that all penetration materials are appliedAbout the Authorwithin the flat pan area of the metal panel and are notJohn A. DAnnunzio is President of Paragon Roofing extended on to the rib. Technology Inc., a construction engineering firm he Roof Curbs founded in 1989. He is the editorial director of Building There are two common types of roof curbs used withEnclosureandatechnicalcolumnistforRoofing metal roof systems. The nonstructural units are designedContractor. He has published more than 100 articles with the same configuration as the metal panel andand has written four books on building exterior issues. move with the panel. These types of curbs are utilizedFor more information, visit www.paragonroofingtech.on lighter units such as skylights and hatches. Structuralcom. He can be reached at 248-936-8744.units are applied to support heavier equipment such asAbout Building EnclosureHVAC units. In these cases, a double curb is used withBuilding Enclosure covers the best architecture practices a structural curb secured to the panels and a secondfor the building envelope in the commercial and residential floating curb applied over the panels to accommodatebuilding & construction industry. Also covering the latest movement. building codes and details, Building Enclosure strives The flashing termination is similar in both instances. Atto provide the crucial information you need for your the high side transition point of the curb, an end cap andbusinesswhen, how and where you want it.www.mrca.orgMidwest Roofer 11'