Metal Wall and RoofTrim & Flashing Information

Like coating systems for panels range from good, better, and best, the same applies to the paint coating for trim materials. 

At McElroy Metal, we’re proud to be one of the few manufacturers to offer PVDF/Kynar 500^® coatings for our entire product line.  We’ve taken that position because we believe in the superior fade and chalk resistance of Kynar 500 products. 

If you aren’t familiar with the long-term benefits of Kynar 500 painted products, learn more about them here.

It’s also important to consider how the trim is attached to the building. 

As the name implies, exposed fastener trim is attached to the panel and substructure with a screw that pierces all three components (trim, panel, and substrate.)  As might be expected, exposed fastened trim is the most economical to purchase and install.   

In contrast, concealed fastener trim uses various cleats attached to the structure, which allow the final trim pieces to hook or engage via an open hem.  While concealed trim applications may use pop rivets at trim laps, they do not involve any visible screws. 

Due to the lower price point and ease of installation, post-frame and commercial applications routinely use exposed fastener trim installations.

In contrast, the desired aesthetics and system life expectancy push most architectural applications toward concealed fastener systems. where the use of cleats, open hems, and pop rivets replace larger visible fasteners.

Residential applications flex either way.  For the budget-conscious owner who doesn't mind a bit of maintenance, exposed fastener trim details can work quite well.  And for the discerning owner with little appetite for minimal maintenance, concealed fastened trim attachment remains the preferred approach.

Yield strength (measured in PSI) is the resistance the steel has to deforming when pressure is applied. The three most common strengths, from strongest to weakest, are 80,000, 50,000 & 37,000 PSI.

Since they are lighter and less rigid, 29 gauge panels generally use stronger 80,000 PSI material to help the panels carry the necessary load.

However, trims made from 80,000 PSI can microfracture at tight bends and hems, which leads to rust and premature failure.  To avoid those issues, some manufacturers skip the hem entirely for their 29 gauge trims, leading to safety issues and a wavy trim appearance.

At McElroy Metal, we've chosen to inventory 80,000 PSI material for our 29 gauge panels and 37,000 PSI, for our 29 gauge trims.  Sure, it costs a bit more to inventory two different coils, but to us, it's the right decision to ensure the best quality and aesthetics for your project!