Metal Roofing Fasteners
A common question that comes up when you start talking about metal roofing, is what type of fasteners should be used with a metal roof. Really there are two key considerations when one thinks about fasteners on a metal roof.
Number one is you want to have a fastener that’s going to secure the roof to the roof deck, so it’s going to hold on and and stay tight, despite whatever types of severe winds or other severe weather comes along down the road. And it has to be specified by the manufacturer of the roofing. The roofing products out there will have all been tested to meet specific criteria in terms of wind uplift and wind resistance, and part of that testing includes the use of certain fasteners. So you want to make sure that your metal roof is being installed with the fasteners that it was tested and proven to be installed with.
The second big thing to think about pertains more to product design. The question is “Are fasteners exposed or are they concealed?” There are two very general types of metal roofs out there; one that has exposed fasteners, and one that has concealed fasteners.
Now one thinks about that, you think about any penetrations are any holes or other types of penetrations and maybe through the surface of the roof, and exposed fasteners obviously would pose a penetration through the surface of the roof system. And whenever you have exposed fasteners that certainly is something that a consumer would want to think about. Not that those systems are inherently bad, but you want to make sure that any exposed fasteners are properly protected with an appropriate durable grommet or washer which seats itself underneath the head of the Fastener, and in turn protects the hole from water infiltration.
Now on the flip side, going with a product that has concealed fasteners, there are two variations of that as well. One is concealed fasteners that are fixed fasteners. Fasteners that go right through the panel and affix it to the roof deck below. The other type is a fastener than actually goes through a clip, and the clip attaches to the roof deck, but the clip in-turn secures the roofing panel in place and holds it in place.
Either one of those systems that will work fine it’s just a matter of how that particular roof system has been designed to be produced and to be affixed to the roof. So when your thinking about fasteners on the roof, you want to think about a couple different things. Make sure that the fastener being used is the fastener that is specified by the roofing manufacturer, and second, just for your own peace of mind, consider whether it is an exposed fastener, or concealed fastener.