Metal Roofing – What Roof Should You Choose?
Not only is metal strong and durable, but metal roofing is low-maintenance, recyclable, and reliable. In addition, metal roofing opens up a variety of style and design options that are becoming increasingly popular in architecture today including hips, slope changes, valleys, transitions, and dormers. Yet choosing a metal roof should be a careful process. Different types of panels are useful in different situations, and depending on how you plan to fasten your roof to structures, metal roofing may not always be appropriate.
There are two main categories of metal roofing options: through-fastened and standing seam. Through-fastened metal roofing panels are available in varying widths, rib shapes, heights, and spacings. Typically, these metal roofing panels are available in 29, 26, 24, and 22 gauge with 26 gauge being the most common. In addition, through-fastened metal roofing panels may be finished with silicon polyester or Kynar finish; and they are either structural or non-structural panels. Structural panels can span across framing members such as joists or beams; while non-structural panels can only be installed over a solid surface.
Through-fastened metal roofing panels provide a number of distinct advantages. First, they are comparatively inexpensive and simple to install. They also feature a diaphragm which is crucial for wind bracing of metal buildings. In addition, there are some disadvantages to through-fastened metal roofing panels. Through-fastened panels may leak if they are not correctly installed and they do not allow for floating due to temperature changes sometimes causing the panels to tear around fasteners.
Standing seam metal roof systems feature exposed fasteners at the eave and end laps only. They allow for thermal movement and are normally manufactured at 24gauge or 22 gauge. Standing seam metal roofing designs are very flexible structurally and architecturally and are classified for water shedding and water barrier systems. These types of metal roofing panels can handle temporary submersion in water at the seams and end laps and feature factory applied mastic at the seams to improve water integrity. Because standing seam metal roofing systems are structural they do not require a deck for installation. Moreover, these metal roofs provide more design flexibility. Moreover, standing seam metal roofing systems tend to be the only barrier between the interior of a building and the outdoors so they tend to be better weather tested.
Keep in mind, this is a very simple description of the different types of metal roofing systems. Deciding which is best for your purposes is worthy of a discussion with a local expert. If your decision comes down to solely to cost, through-fastened metal roofing systems are probably the least expensive option in the short term. However, standing seam metal roofs provide better protection against the weather and may be a more suitable option in the long-term.