Unistrut Defender

Although Hot-Dip Galvanized is the most common finish, there are some serious drawbacks when using HDG for outdoor applications. First, Hot-Dip Galvanized steel typically reaches 5% red rust after just around 1000 hours of continuous salt spray exposure based on industry standard testing. As a result, the anticipated service life for galvanized steel in outdoor applications is often less than that of the facility in which it is installed, requiring a complete teardown and reinstallation at some point throughout the life of the building. Over the long term, particular attention must be given to exposed struts and fittings fabricated from galvanized steel, since these components are especially vulnerable to the elements.

For these reasons many engineers and builders instead utilize stainless rather than rely on galvanized. Stainless offers great performance in comparison, but at what price differential? Stainless steel is often two to five times more expensive than hot-dip galvanized steel for a given application.

So, the tradeoff has been whether to have the superior protection of stainless at a higher cost, or lesser protection at a significantly lower cost. Until now, no effective alternatives have been available. Engineers and contractors still want improved protection from corrosion, while maintaining a lower price point than stainless steel. Fortunately, new coatings that have come on the market are making a huge impact on the construction industry and are providing better coating options for strut, fittings, and other members.