McNichols Steel vs. Fiberglass Grating: How to Choose

I review grating specifications at McNichols before they go out the door. It's a role I've had for about 4 years now, and I look at roughly 200 unique configurations annually—steel, fiberglass, aluminum, you name it.

One question comes up more than any other: "Should I use fiberglass grating or steel grating?"

I get it. They look similar in catalogs. Both come in standard panel sizes or fabricated sections. Both support loads. Both are grating. But the right choice depends on things you won't see until the material's been in service for a few years.

Here's the comparison I actually walk through when a customer asks me this. Four dimensions: structural performance, corrosion resistance, total cost, and compliance documentation.

Structural Performance: Steel Takes the Raw Load, but Don't Dismiss Fiberglass

Steel is stronger. Full stop. If you're dealing with heavy impact loads, forklift traffic, or concentrated point loads, McNichols steel grating with properly sized bearing bars is the safe, proven choice. A 2-1/4" steel bearing bar with the right cross bar spacing carries loads that would make a fiberglass engineer sweat.

But here's the part that surprises people: in a lot of pedestrian applications, you're using steel at a fraction of its rated capacity. You're buying 10,000 pounds of load rating to hold a person who weighs 200. That's not high-performance engineering—that's habit.

Fiberglass grating is engineered with specific resin systems—vinyl ester, polyester, phenolic—and each has different load characteristics. It deflects more than steel under the same load. In some applications, that's actually a benefit. Fiberglass has a bit of flexibility that helps absorb impact energy. And in wet or corrosive environments, that flexibility—combined with the material's resistance to degradation—can keep a walking surface safe long after steel has corroded and started losing cross bars.

My bottom line on structural performance: for heavy dynamic loads, choose steel. For moderate loads, don't dismiss McNichols fiberglass grating just because steel is "stronger." It's about matching capacity to the actual need. You wouldn't spec a 100-ton crane to lift a pallet of bricks.

Corrosion Resistance: Where Fiberglass Stops the Bleeding

This is where fiberglass makes its strongest case, and it's not close.

Steel corrodes. Eventually. Even hot-dip galvanized coating fails in tough environments—coastal salt air, chemical plants, wastewater treatment, pulp and paper facilities. I've seen galvanized steel grating fail in 5 to 7 years in severe chemical atmospheres. Not surface rust. Actual loss of cross bars, loose sections, a real worker safety hazard.

Fiberglass doesn't have that failure mode. It's inherently resistant to a broad range of industrial chemicals and will not rust. A fiberglass panel installed in a chlorine environment or a treatment plant isn't fighting a losing battle against the atmosphere. It just... stands there. Year after year.

UV degradation is a real consideration, though. If you install fiberglass in direct, intense sunlight, it needs UV inhibitors in the resin system to prevent long-term surface degradation. That's manageable—you just have to specify it. Steel doesn't care about UV exposure.

Here's the counter-intuitive conclusion: in aggressive environments, fiberglass isn't the "light-duty alternative." It's the material that will still be load-bearing 20 years from now. Steel, in the same environment, will be on its second replacement by then.

Think about which material is actually the structural option.

Total Cost of Ownership: Steel Wins the Battle but Loses the War

The initial price of steel grating is almost always lower. I'm not going to tell you steel costs more. It doesn't.

But total cost of ownership? That's a different story.

Let me share something from my own experience. We had a customer in a water treatment plant pricing both options. The steel bid came in around 25% cheaper upfront—maybe 20-30% depending on the exact spec, I'd have to check the quote to give you the precise number. Every spreadsheet analysis pointed to steel. My gut also said steel was the obvious value pick.

But then we looked at the full lifecycle. The re-coating cycle that galvanized steel would need in that atmosphere. The unplanned replacement we expected around year 8 or 9, based on what we see in similar facilities. And the downtime—the actual cost of shutting down a section of a treatment plant to swap out corroded grating.

When the full math was done, fiberglass was less expensive by year 6. And it was going to outlive the steel by 15+ years in that environment.

My gut had said steel, because steel is "cheaper." The numbers said fiberglass. I went with the numbers. And I've watched the same calculation play out in dozens of corrosive-environment projects since then.

I should add one caveat: this math depends on the actual conditions. I know what environments drive corrosion, but I'd rather have a conversation with you about your facility than give you a generic rule and call it "analysis." Your conditions may differ.

If you're in a clean, dry interior? Steel wins on cost. It doesn't even need meaningful maintenance for decades. The performance and the price align. But in corrosive environments, you're not paying extra for fiberglass—you're paying upfront to avoid buying steel grating again in a decade.

Compliance and Documentation: Whatever You Choose, Be Able to Prove It

Now, this isn't really a fiberglass vs. steel issue. It's a supplier issue.

OSHA has specific requirements for walking-working surfaces, including grating, under 29 CFR 1910.23 (verify current requirements at osha.gov). Load capacity, slip resistance, and fall protection are all covered. Many state and local building codes go further—ICC/ANSI A1264 addresses safety requirements for industrial stairways, walkways, and open grating surfaces.

That means the material you install has to meet the standard and you need to be able to document it. When I'm reviewing an order, I'm looking for complete spec sheets, material certificates, load test documentation, and any certifications your jurisdiction requires.

I've seen this exact scenario: a project ready to install grating, and the material shows up without the paperwork to prove compliance. That was a $22,000 schedule delay in one case I dealt with—labor crew went home, the timeline slipped, legal had to get involved. That wasn't a fiberglass problem or a steel problem. It was a sourcing problem.

Whether you choose steel or fiberglass, ask your supplier for the full documentation package and make sure it arrives with the material. If a supplier can't provide certification, that's a red flag that overrides any price advantage.

Regulatory information provided here is for general guidance only. Consult official sources for current requirements.

So: McNichols Steel Grating or Fiberglass Grating?

Here's the practical decision path I'd give anyone asking this question.

Choose steel grating if:

• Your application involves heavy concentrated, impact, or dynamic loads
• The environment is dry, indoor, or otherwise not aggressively corrosive
• Initial capital cost matters more than long-term maintenance cost
• You need the familiar track record of carbon steel with decades of performance data

Choose fiberglass grating if:

• The environment is corrosive—chemical exposure, wastewater, salt air, coastal atmosphere
• Slip resistance in wet conditions is critical
• Installation weight matters; fiberglass is about a quarter of the weight of steel
• You need electrical non-conductivity or magnetic transparency
• Lifecycle cost analysis in your conditions puts fiberglass ahead

If you're genuinely uncertain? Ask someone who sees both materials in the field daily. I'd rather a customer talk to the McNichols technical team and end up buying from someone else than spec the wrong material and deal with the consequences for a decade. An informed customer is a better customer for everyone.

The Same Quality Lens Applies Beyond Grating

The thinking I've outlined here—matching material properties to site conditions, verifying compliance documentation, considering total cost rather than unit price—applies across metal building products in general. Whether you're reviewing metal cladding specifications for an exterior renovation, evaluating a metal siding manufacturer for a new warehouse, or working through stair systems compliance requirements for an industrial mezzanine, the principle is the same: know the standard, document the compliance, and buy from a supplier who understands the context.

At McNichols, that's the lens I apply to every order that crosses my desk. Not "which is cheaper" or "which is stronger," but "which is right for this application, at this location, under these conditions?"

That's the question worth answering.