The Benefits of Building a Deck with Steel Deck Joists

When building a deck most homeowners only consider what decking boards they want installed. However the most critical decisions you should make is the choice of materials for your deck’s frame.

Traditionally, pressure-treated wood has been the go-to option for deck joists. Nowadays this material has significant drawbacks that can affect the longevity and stability of your deck.

Enter steel deck joists – a superior alternative that offers numerous benefits over traditional wood framing.

The Problems with Pressure-Treated Joists

Inconsistency and Labor-Intensive Preparation

One of the primary issues with pressure-treated wood joists is their inconsistency. Pressure-treated lumber often suffers from crowning and varying sizes, forcing contractors to spend considerable time hand planing the tops of each joist and meticulously leveling the entire surface.

This labor-intensive process is necessary to achieve a flat deck surface. Unfortunately, even after this painstaking effort, wood joists are susceptible to seasonal changes in humidity and temperature, which cause them to move and warp over time.

As a result, the deck surface can still become uneven, leading to an unsightly and uneven deck surface which can lead to people tripping.

Limited Lifespan and Durability

The lifespan of pressure-treated wood joists has also become a significant concern. Historically, pressure-treated wood containing arsenic was known for its durability and long life span. However, due to health and environmental concerns, arsenic-treated wood has been phased out and replaced with new, less toxic treatments.

Unfortunately, these newer treatments have not proven to be as long-lasting. Many homeowners are finding that their pressure-treated frames are rotting out in as little as 10 to 15 years.

This is a major issue when considering the availability of long-lasting decking materials like composite, HDPE, PVC, and hardwood decking, which can last upwards of 50 years. Using short-lived pressure-treated joists undermines the longevity of these superior decking options.

The Advantages of Steel Deck Joists

steel deck framing

Superior Longevity and Stability

Steel deck joists offer a remarkable improvement in both longevity and stability. Unlike wood, steel joists do not warp, twist, or shrink with changes in temperature and humidity. This means they are ready to install without all the labor of fixing pressure treated joists. Additionally they are significantly lighter in weight so one person can easily move a steel deck joist by themselves.

The added stability ensures that your deck surface remains flat and even over time, reducing maintenance and extending the life of the deck. Steel joists are also immune to rot and termite damage, common problems that plague wooden joists.

Fire Resistance

In areas prone to wildfires, building codes are increasingly prohibiting the use of wood framing due to its combustibility. Steel deck joists provide a non-combustible alternative with a Class 1A fire rating, offering peace of mind and compliance with stringent fire safety regulations. This fire resistance makes steel an ideal choice for decks in wildfire-prone regions.

Enhanced Lifespan

When investing in premium decking materials that can last for decades, it’s essential that the supporting structure matches their longevity. Steel deck joists are designed to last as long as or longer than high-end decking materials, ensuring that your entire deck structure remains reliable and worry free for many years.

This makes steel joists a smart long-term investment, especially when considering the potential costs and hassle of replacing a rotted wood frame.

Steel deck joists are triple coated to offer many years of protection against corrosion and rust. They are first galvanized, then primed and then sprayed with a durable UV resistant top coat.


Building a deck with steel deck joists provides a host of benefits that address the shortcomings of traditional pressure-treated wood. From ensuring a stable and even deck surface to offering superior durability and fire resistance, steel joists are the ideal foundation for any long-lasting decking project. Whether you’re using composite, HDPE, PVC, or hardwood decking, pairing these materials with steel deck joists will help you create a deck that stands the test of time, providing beauty and functionality for decades to come.

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