3 Top Factors to Consider when Choosing Fasteners for Metal Roofing

Posted on: 26 April 2019


It is the little things that count. While this is a common phrase that people use in day-to-day life, it is one that experienced roofers understand well. While metal roof fasteners might seem like a small part of a roofing system, the fasteners hold the system together. As a rookie roofer, your choice of roofing fasteners determines the roof's performance and in essence the entire building's. Therefore, it is essential to use ideal fasteners. You will help your clients to save time, money and the headache of always having to repair a continually leaking roof. This article looks at the factors to consider when choosing fasteners for your metal roofing project.

1. Fastener Material -- Fasteners are made from different coated metals; therefore, roofers must first confirm the type of coating as well as the material used to manufacture fasteners. It can be attributed to possible galvanic action between two different metals which often leads to premature failure and consequently leakage. For instance, using copper flashings on aluminium roofing will lead to natural corrosion of the coated aluminium roofing panels. Therefore, is is a roofer's duty to ensure that they use the same type of metal throughout the metal roofing system. It will eliminate any galvanic action between the metals thereby enhancing the roof's durability.

2. Washer Material -- When installing metal roofing, it is common for roofers to use plastic washers with the fasteners. The plastic fasteners ensure a tight fit and eliminate any chances of leakage. However, while plastic washers will prevent leaks, they are discouraged on metal roofing systems. The reason is that using plastic washers forces roofers to inspect the screws to ensure they are adequately compressed and that they are not kinked. If such inspection is not conducted, any exposed plastic washers will degrade faster thereby compromising the tight seal between the metal roof panels and the screws. Moreover, red lists might prevent the use of certain washer materials such as neoprene washers. Therefore, it is vital for roofers to refer to the restricted materials list when choosing the type of fastener to use.

3. Pre-Drilling or Pilot Holes -- Today, most roofers consider self-drilling screws to be a godsend for their metal roofing needs. The reason is that self-drilling screws have a built-in drill bit along its length which eliminates the need for a pilot hole. While self-driving screws save time, they are not suitable for metal roofing because it is impossible to ascertain if the plies are correctly aligned or if you are drilling in the correct position. Therefore, instead of using self-drilling screws, roofers are advised to use self-tapping screws to fasten metal roof panels for accuracy reasons.