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A Guide to Aluminum Decking Systems

A secure grandstand is the backbone of a safe and successful event. As such, you need it to be rock-solid, reliable, and ready for anything.

One of the key elements behind a stable grandstand is the decking system—the horizontal surfaces where people sit, stand, or walk. It also includes support structures to distribute weight evenly and prevent sagging or collapse.

Decking systems can be made from several different materials, but aluminum is often the go-to choice due to its strength, durability, lightweight nature, and corrosion resistance. It’s a great pick for outdoor events where weather conditions may vary.

When choosing the right aluminum decking system for your grandstand or bleacher project, there are several options to consider. Each type has its unique features, benefits, and potential drawbacks.

In this post, we’ll explore a few to help you make an informed choice. Let’s dive in:

The Different Elements of a Decking System

Before we move on, here’s a quick overview of the main components of a decking system:

  • Deck Surface: The top layer where people sit, stand, or walk.
  • Support Beams: Large horizontal structures providing primary support.
  • Joists: Smaller horizontal structures connecting support beams for even weight distribution and added stability.
  • Risers: Vertical components supporting the deck surface.
  • Fasteners: Bolts, screws, and other hardware holding the system together.
  • Openings: Small gaps between the deck surface and the ground.

With this covered, here’s a look at the different aluminum decking systems available.

Semi-Closed Deck


“The bitterness of poor quality stays far longer than the sweetness of a low price”…Ben Franklin

Semi-closed decking systems feature openings less than 4 inches between the deck surface and the ground. These openings allow water and trash to pass through the opening to the ground. This causes the owner to clean both top side and underneath the grandstand.

This system can also create a slightly “spongy” feel when walked on. While the average spectator might not notice this, experienced grandstand designers often prefer other aluminum decks unless they’re on a shoestring budget.


  • Cost-Effective

Semi-closed decks are typically more affordable than fully closed or interlocking systems, making them ideal for projects with financial constraints.


  • Maintenance Concerns

Trash can fall through the openings and collect underneath the bleachers. You’ll need regular cleanup to keep the area tidy and presentable.

  • Spongy Feel

Because a semi-closed deck block is slightly flexible, it can feel less stable compared to other systems. If you’re looking for the most solid and firm surface possible, this might not be the best choice.

Fully Closed Decking Systems


Fully closed decking systems provide a solid surface with no gaps. You’ll usually find them in places where cleanliness and safety are top priorities, such as schools, sports facilities, and public arenas.


  • Reduced Maintenance

With no gaps, there's no way for trash to fall through to the ground. Hence, it’s much easier to keep the area under the grandstand clean.

  • Enhanced Safety

A solid surface prevents small items from slipping or getting stuck between the cracks. If you have children around or often deal with small objects like coins or keys, you’re more likely to benefit from this feature. It also keeps pests like rodents or insects from nesting beneath the decking boards.

  • Better Look

Fully closed decks have a polished, uniform appearance that improves the overall look of the grandstand.


  • Spongy Feel

Just like semi-closed decking, fully closed systems can feel less firm underfoot because they lack the additional support offered by interlocking designs.

  • Higher Cost

Fully closed decking systems can be more expensive to install compared to semi-closed systems.

No Penetrating Interlocking Systems


Fully-closed interlocking deck

Often seen as the premium choice among aluminum deck systems, these decks have interlocking panels that snap together without needing screws or bolts that go through the risers. Not only does this prevent problems like rusting hardware, but it also makes the deck more durable.



  • Superior Stability

Interlocking deck boards feel solid underfoot and are ideal for high-traffic areas. The unique design gives you a firm, stable surface that doesn’t feel spongy.

  • Low Maintenance

No hardware means there’s no risk of screws or bolts rusting over time. You get a longer-lasting deck at half the maintenance chores.

  • Clean Surface

The tightly fitting interlocking panels prevent trash from falling through and keep the area under the deck clean.


  • More Expensive

No penetration interlocking decks are generally more expensive because of their advanced design and materials. However, the long-term benefits, like durability and low maintenance, can make this initial investment worthwhile.

Structure Types for Aluminum Decking Systems

Aluminum deck systems can also have different structures. The structure supports the decking and ensures it can handle the weight and movement of spectators. Here are two common structure types:

I-Beam Structure


An I-beam structure offers robust support and is a popular choice for large-scale projects. Known for their I-shaped cross-section, I-beams deliver exceptional strength and durability, which is ideal for venues expecting heavy use and exposure to various weather conditions.

Angle-Frame Structure


Angle frame structures provide a simpler and more cost-effective solution compared to I-beams. While they might not be as strong, they still offer sufficient support for smaller grandstands or bleachers. Angle frames are ideal for schools, community centers, and other venues where the load requirements aren’t as high.

Guardrail Types for Aluminum Decking Systems

Safety plays a big role in any grandstand design, and choosing the right type of guardrail is essential to keep everyone secure. Besides providing the necessary barriers to prevent accidents, guardrails also contribute to the overall look and feel of your venue.

Chain Link


Chain link guardrails are made from interwoven steel wires that create a diamond pattern mesh. It’s a great design because it’s strong and lets people see through it, so they don’t feel closed in.

Being relatively cheap to produce and install, chain link is great for tight budgets. Plus, if one part gets damaged, you can easily replace just that section.

Vertical Picket


Vertical picket guardrails have evenly spaced vertical bars connected by horizontal rails. The clean lines and symmetrical design give them a polished and upscale look.

Aesthetics aside, the vertical bars prevent climbing and make sure small kids can’t squeeze through. You can also add decorative elements like finials or scrollwork to the rails to match the architectural style of the venue.

How to Choose the Right Aluminum Deck System for Your Grandstand

Perhaps the biggest decision you’ll make for your grandstand project is choosing the right aluminum decking installation. To help you make the best choice, here are some key points to consider:

Assess Your Budget

Figure out your budget first. Your spending limit will guide you toward the options that are available. Remember, investing a bit more upfront can save you money on maintenance and repairs down the line.

Consider the Venue

Think about where your grandstand will be. Is it outdoors? If so, you need a system that can handle the weather, including good drainage to prevent water pooling. For high-profile events, you might want something that looks sleek and polished.

Evaluate Maintenance Needs

Be realistic about how much maintenance you’re willing to do. Some decking systems need regular cleaning and upkeep, while others require less maintenance. Also, consider how easy it is to repair the decking if needed.

Think About Longevity

You want a decking system that lasts. Check for durability features like resistance to rust and corrosion.

Safety First

Make sure the decking system provides a stable surface that won’t cause trips or slips. Consider systems that prevent small items from falling through and causing hazards.

Get State-of-the-Art Grandstands with GT Grandstands!

The right aluminum decking system can ensure your grandstand is safe, durable, and visually appealing. By considering your budget, venue, maintenance needs, longevity, and safety, you can make an informed decision that will benefit you for years.

At GT Grandstands, we’re committed to delivering outstanding quality at competitive prices. Reach out to get started on building a grandstand that exceeds your expectations. Our experts will guide you every step of the way.

Contact us today!