What follows is a description of each form and advantages and disadvantages of each.
• Agricultural Panels:
Agricultural panels have ribbed shapes pressed into them (Figure 4). Exposed fasteners with rubber gaskets are used to attach the panels to the roof deck. Applying this form of metal panel directly to a plywood roof deck usually results in early failure of the roof. The expansion and contraction factor of metal roof panels is so great that the fasteners can become loosened causing panels to blow off.
Expansion and contraction can also cause the holes around fasteners to become enlarged, causing leakage. This is the reason that manufacturers of agricultural panels usually do not recommend their use on residential structures.
• Standing Seam Metal Roofing:
Standing seam metal roofing has folded seams and all fasteners are covered by the seam folds (Figure 5). Copper, easily shaped and highly durable is often used for standing seam roofs. When highly durable metal is used, coupled with proper installation, standing seam roofs are extremely long lived. Installation of this type roof is labor intensive and requires skilled installers. Therefore it is best to leave installation