Mezzanine Bar Grating Essentials

Posted by Nucor Grating on Jan 23, 2019 9:29:30 AM


What Is a Mezzanine?

The term mezzanine comes from the Latin word medianus which means median.  Essentially, a mezzanine is a median or middle floor inside a building. Local codes may vary, but mezzanines are typically not counted as an additional floor in a building, which is one of numerous reasons why mezzanines are preferred. Building vertically allows warehouses to double and triple their workable space easily and efficiently. (Not to mention, mezzanine platforms are cost-efficient.) Mezzanines provide stable structure for storage, elevated walkways, and additional workforce space and are commonly used throughout distribution facilities and manufacturing plants.

Choosing the right mezzanine flooring or decking is your first task. Consider what the use of your mezzanine structure will be. What type of traffic will be using the structure? (Workers, rolling carts, etc.) What is going on top of the mezzanine floor? Calculating your weight bearing requirements is critically important to protect workers. Will your mezzanine be permanent or temporary? Will you need additional support to compensate for a moisture-rich or caustic environment? Are you planning to build an office with your mezzanine platform?

Knowing the answers to these questions will help you in determine the ideal mezzanine floor for your needs.

Common Mezzanine Floor Types

There are multiple types of mezzanine flooring and decking materials to choose from:  

  • B-Decking

  • Plywood Over Corrugated Metal

  • Concrete

  • Bar Grating!

Why Use Bar Grating for Mezzanines?

Bar grating is known for its ability to withstand a tremendous amount of weight. Mezzanine floors are made with bar grating because of it offers (1) strength and uncompromised support, (2) allows for open space (to allow light, air, and water to pass through), and (3) offers long-term cost savings among numerous other benefits.


Perpendicular bearing bars are joined together by cross bars to form load-bearing panels. Due to this construction, bar grating can carry load much heavier than other products with comparable size and weights.  A popular size of bar grating for mezzanines, 19W4, 1”x1/8”, and weighs 5.03 pounds per square foot.

Steel Bar Grating Weights (Theoretical)

Imperial Weights

Metric Weights


Open Space

The open space in the decking allows for ventilation and air flow, light to filter through, and temperature control. The same size grating as mentioned earlier, 19w4, 1” x 1/8” with 4” cross rods has an 84% open area. See our catalog open areas chart.

Long-term Cost Savings

The durability and longevity of using metal grating is unmatched, making it a sound investment—saving money up-front, reducing maintenance costs, and offering long-term value. Also, the nature of bar grating allows HVAC systems to be more effective and cost efficient.

Other Benefits for using Bar Grating for Mezzanine Flooring

Outside of strength, open space, and long-term cost savings, bar grating offers a number of other benefits.

  • Oftentimes installation of sprinkler systems is not necessary underneath mezzanines, though you should check the local building codes to be sure.

  • Conversely, if sprinkler systems (and other piping applications) are desired, bar grating allows for easy attachment underneath the mezzanine along with other piping.

  • Sturdy and safe flooring for workers

If strength, open space, and long-term value is a priority for your project, then bar grating is the flooring of choice for your mezzanine.

What Are the Specifications of Bar Grating in Mezzanines?

The most common size grating are: 19w4, 1” x 1/8” or 19w4, 1” x 3/16”, though there are numerous options available which can be found in our catalog.

What Is the Typical Type of Bar Grating for Mezzanines?

  • Welded Steel (Forge-Welded): The most common mezzanine floor application, forge-welded grating offers strength and open space while also being cost effective. Should your project need it, serrated steel grating offers a slip-resistant surface for increased traction.

  • Press-Locked - Press-Locked grating has a smooth surface, and is often used within the food industry (outfitted with stainless steel).

  • Fiberglass Reinforced Plastic (FRP): FRP is also an alternative offered.

  • Swage-Locked: Aluminum Swage-Locked Grating is available, but not commonly used for mezzanine decking.

  • Riveted: Riveted Grating is another type of grating that offers excellent strength, but is not commonly used for mezzanine decking.

Metals for Mezzanine Grating

The most common metal used when constructing mezzanine platforms and flooring is carbon steel. However, warehouse mezzanines may be equipped with stainless steel for caustic environments. Aluminum options are occasionally requested for when lightweight applications are necessary.

Mezzanine Grating Finishes

  • Painted: Black, silver, and dark grey

  • Unpainted: Mill finish

  • Galvanized: Use in exterior or corrosive environments

How to Order Bar Grating for Mezzanines from Nucor Grating?

Ordering warehouse mezzanine structures, platforms, and mezzanine flooring solutions with Nucor Grating is fairly simple! Once you have identified the type and size of bar grating your project needs

Step One: Determine what type of mezzanine floor is required.

  • Spacing and cross rod placement (i.e. 19w4 or 19w2)

  • Bearing bar thickness and height (i.e. 1” x 3/16”)

  • Material type (i.e. carbon steel)

  • Surface (smooth or serrated)

  • Finish (i.e. painted black)

Step Two: Please provide one of the following:

  • Engineer Cut List

  • Perimeters of Area to be Constructed

  • Approximate Square Footage Total

Step Three: Please specify (1) location of support centers to be used, (2) loading requirements (whether pedestrian, machinery, or pallet traffic).

Example Order: Here’s a helpful example of a mezzanine bar grating order:

“19w4, 1” x 3/16”, carbon steel, serrated, painted black

40x100’ Mezzanine, supports are on 4’ center with a load requirement of 125 pounds per square foot”

Looking for a Mezzanine Grating?

Nucor Grating is dedicated to providing the highest level of service for mezzanine platforms, flooring, decking, and special applications. We offer NAAMM standards bar grating for stair treads, providing warehouses and distribution centers with improved lighting and open space in tandem with mezzanine structures.  

Browse our entire bar grating products and feel free to reach out and speak with an experienced professional today! We would be glad to help.