Proper Installation Procedures and Tools for Metal Roofing and Cladding Panels SFS Group, USA In the majority of roofing and cladding applications, metal panels are installed onto substructures. Although seemingly trivial, the selection of the correct tools and the application of proper installation procedures is paramount for the completion of a successful job. This article will outline the necessary tools and techniques required to ensure installers successfully complete projects without damaging fasteners or application substrates.
Select the Correct Drive Bits and Metal Panel Installation Procedure
Selecting an incorrect drive bit can result in serious efficiency and performance issues. A recessed magnet should be used for external drive fasteners and the correct size and design drive bit is always used for internal drive fasteners. It is equally important to properly tighten fasteners into the application substrate. The majority of roofing and cladding fasteners will feature some type of bonding washer to provide a water-tight seal. Care must be taken to correctly drive the fastener into metal panels. Use the image below as a guide.
Wood Applications
Source: Metal Construction Association
Which to Use for Metal Roofing or Cladding Panels: Drill Guns or Impact Drivers?
Although similar in appearance, drill guns and impact drivers have differences that will affect the performance of fasteners. During metal panel installation, drill guns provide a constant rotational torque. In contrast, impact drivers produce more torque applied in short bursts. This results in “impacts” which drive screws more effectively. In addition, impact drivers are typically more compact and tend to slip less frequently. On the surface, impact drivers appear to be an obvious improvement over drill guns. However, the increased torque and “impact” action may result in damage to the fastener, the sealing washer and the installation substrate. Fasteners can be damaged in three different ways by impact drivers. First, for painted fasteners, chipping and damage can occur. This will result in both an unfavorable appearance and increased corrosion risk.
Metal panel installers should also take care to select a drill gun set to the correct rotational speed (RPMs). The following tables can be used as general guides for selecting the correct installation speed. However, it is a good idea to check with the fastener manufacturer for exact specifications.
Carbon Steel or 410 Stainless Steel
300 Series Stainless Steel
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FLORIDA ROOFING | October 2022
Second, depending on the material composition of the fastener, the internal or external drives can be damaged. For soft stainless alloys and zinc/ aluminum alloys, the use of an impact driver can permanently deform internal drives and “grinddown” external drives. In some cases, the drive will wear down prior to full installation. In addition, repair