Metal Construction News, May 2018

Oversized Attachment Advice When installing metal panels its important to understand how they are attached to the substrate or these days more likely the substructure i e cladding attachment system When large areas of opaque wall are covered with a single panel all of the wind load from the area the panel covers is funneled down into the connections around the perimeter typically Therefore those connections end up feeling a substantial point load and are generally engineered on a job by job basis It is crucial to be sure the entire wall system underneath the panel is designed for the reaction these point loads induce for structural stability It is not safe to assume the load will always be dispersed evenly and uniformly to the substrate substructure and by doing so may lead to structural deficiencies and frankly a dangerous situation Brian Nelson general manager Knight Wall Systems Deer Park Wash you establish how to lift you will need to decide if there will be any bow out in the panel as you are setting the initial fastening points wind insulation This can be minimized with personnel on a second lift at mid height Moving your initial fastening point from the top down one girt level will decrease the distance to the initial bottom fastening point Maintaining proper laps and edge alignment is requisite when oversized metal sheets are installed as any misalignment at one end translates into a major misalignment at the other end Additional man lifts may also be warranted in wall applications primarily to maintain control of the panel at mid height during installation but also to limit bow out says Shelton If bow out is not controlled and screw installation sequence is haphazard then the installation itself may introduce oil canning and other visually unappealing conditions Wallace says stiffening and leveling play an important part in oversized panel installation success Larger panels will most likely require stiffeners of some type he says Know that stiffening isnt necessarily there for flatness It can help somewhat but really more to meet the performance requirements based on the design loads Also start with a properly leveled flat part Traditionally if a fabricator is working with a product that is subpar in flatness it could lead to a panel that is not flat and could result in oil canning Additionally expansion and contraction must be taken very seriously when building larger panels and ensure that the design works for the application Burlington Ontario Canada based AXYZ Internationals PANELBuilder CAD CAM software has templates to assist in creating mounting holes for oversized panel stiffeners Peachtree City Ga based MetalForming Inc s folding machines have innovations that allow longer sized panels with varied geometric shapes to be produced Art Hance president of Washington N J based Hance Construction Inc makes sure his erectors comply with manufacturers and industryrecommended panel installation techniques It is critical with longer panels that they are plumb as just a slight misalignment will be read as a sawtooth at the bottom of the panel he says This is especially noticeable when there is masonry walls with panels above We are also seeing issues with newer high R value panel systems with longer fasteners The longer panels shrink and grow with temperature differentials and lead to fasteners failing This can be exacerbated by improper use of impact guns for wall fasteners Oversized metal panel installation Photo courtesy of Riess Construction Correct metal panel installation Photo courtesy of Chief Construction May 2018 METAL CONSTRUCTION NEWS 47 www metalconstructionnews com