FACT
There are many types of fasteners that can be used when installing metal roofing.
ANALYSIS
The type of fastener that works best in any given situation is determined by the type of roofing material that is being installed and the manner in which it is being installed.
SOLUTION
One of the first things to consider is that the metal of the fasteners must be compatible with the metal of the roofing system (see Technical Bulletin #42 on Electrolysis and Dissimilar Metals). Steel fasteners are used with steel roofing, copper with copper, aluminum with aluminum, etc. The next issue is that, if the roof system utilizes fasteners that are exposed to the weather, then the fasteners should have a neoprene washer for sealing or they should be covered with a quality sealant after they’re installed. Additionally, exposed steel fasteners should be painted. When installing fasteners into very hard or brittle materials, the use of self-drilling, self-tapping screws is important. When using nails, ring shank or spiral shank nails are far superior to smooth shank nails in terms of pull-out resistance. There are instances when, particularly with aluminum roofing, it will be desirable to use stainless steel nails that are compatible with the aluminum. These instances occur when the metal roof panels are being installed over a substrate that is very hard, brittle, or one that requires screws rather than nails.
