Architectural Considerations for Choosing Fasteners

by Paul Deffenbaugh | September 1, 2020 12:00 am

When you specify other building components—façade material, roofing, windows and more—the primary consideration is the quality and corresponding life expectancy of those products. You want to know how long these materials will last for the building owner. It should be the same with fasteners. Like any other product, durability is a major factor in the final decision process. We all hear it time and time again, but it’s worth a reminder. The building you erect will serve your customer only as long as the component with the shortest life expectancy.

Ask About Testing

If a fastener supplier can’t offer you any kind of testing results, there’s a reason. Almost all suppliers have conducted some kind of testing and it’s not too complicated to understand the differences. The most common and decisive test for exposed fasteners is a salt spray test required to meet ASTM B117.

In the ASTM B117 test, fasteners are subjected to a steady spray of salt water in a controlled environment. Those fasteners coated with a standard zinc coating may begin to show signs of weathering—rust—in less than 100 hours. In a field application, this translates into a fastener showing signs of corrosion as early as a year or two, depending on where in the country the building is located. Find a supplier that tests fasteners for 1,000 hours or even 3,000 hours. Fasteners that endure even the 1,000-hour test, will last 20 years or more in the field before showing signs of corrosion.

Ask About Materials

Whether you’re fastening sheets with a Galvalume or galvanized substrate, the material your fastener is made of must be compatible for the longest service life. Stainless steel 304 fasteners will cause galvanic corrosion with either Galvalume or galvanized panels, meaning the panel will sacrifice itself. Obviously, that shortens the life span of the panels and, ultimately, the building.

With Galvalume or galvanized panels, it’s recommended you use a mechanically zinc galvanized carbon steel fastener. For both, all fasteners should have a top coating for additional protection.

Ask About Paint

The two most common methods of fastener color matching are wet paint and powder coating. Wet painted fasteners are easier to color match and minimize chipping. Powder coated fasteners are subject to chipping with no way to repair that chip. Wet painted fasteners can be touched up in the field without removal.

When it comes to paint providing additional corrosion protection, it’s important to remember, adhesion is everything. Paint can only add protection if it remains on the part.

Ask About the Drilling Points

Obviously, to have a fastener do its job, it’s necessary to get the fastener through the panel and into the framing. Every time you put a hole in a panel, you’re compromising the integrity of that panel. That’s why it’s important to get through the panel immediately and cleanly.

The point of the fastener is integral to success. If you select a drill point that is too short for the total material thickness, when the screw binds, it often shears below the panel surface causing a creating a hole that needs to be filled to prevent leaking.

Suppliers offer a variety of fasteners with a variety of drilling points. Ask your supplier for what’s best for your job.

Ask About Service

A good supplier will be able to get you what you want and when you want it, while providing you value. Working with an experienced sales staff and a company with a solid reputation within the metal construction industry goes a long way to help you grow your reputation and earn more business.

---

Don Benson is the sales manager for East Cost Fasteners and Closures Inc.[1], Walkerton, Ind., a division of Plyco Corp., Elkhart Lake, Wis. With 20 years of fastener background, he has been involved in all aspects of the fastener pipeline including sales, manufacturing and quality assurance programs.

Al Geisthardt, lead engineer of Plyco Corp.[2], has been involved in the construction industry for more than 35 years. He oversees product development and quality testing programs at the company.

Source URL: https://www.metalarchitecture.com/articles/architectural-considerations-for-choosing-fasteners/

---