While standing seam roofing systems have been used for generations, 138T and 238T panels feature technological advances in roofing that set a new standard for standing seam performance. 138T and 238T systems are classified as symmetrical standing seam systems that feature mechanically seamed caps. This product family offers many advantages including patented recover solutions featuring the industry's best method to recover existing metal or shingle roofs. The most important advantage of the 238T and 138T systems are that they are easy to repair or alter after installation. Unlike asymmetrical standing seam systems, individual 138T and 238T panels can be removed and replaced. With Galvalume roof life expectancy approaching 60 years, this ability to replace individual panels is very important. Mechanical seamers and hand crimpers are available for rent through Developmental Industries