N Deck Supplier: Deep-Rib Steel Roof Deck for Long Spans and Heavy Loads
When your project calls for wide column spacing and a roof system that carries serious load, you need an N deck supplier who actually stocks the profile, cuts it to your dimensions, and ships it before your crew runs out of work. That’s where we come in. At Keystar Industries in Eagan, Minnesota, we keep USA-made Type N roof deck on the rack, size it correctly for your span, and get it on a truck the same day or next day. No guessing, no three-week lead times, no “we can special order that.”
Type N deck is the deepest standard roof deck profile on the market, with a full 3-inch rib. That deep rib is the whole point. It gives the panel the section properties to span farther and hold heavier roof loads than shallower profiles, which means fewer joists, fewer purlins, and a faster, leaner roof structure. Below, we’ll walk through exactly what N deck is, when to specify it, how the gauges work, and what to look for in a supplier so your next big-span roof goes up clean.
What Is Type N Roof Deck?
N deck (also called N roof deck or deep-rib roof deck) is a structural steel roof panel with a 3-inch rib depth and roughly 24 inches of coverage per sheet. It sits at the top of the standard roof deck family alongside A, B, C, and F profiles, but N stands apart because of that deep rib.
Think of the rib like the web of a beam. The taller the rib, the stiffer the panel and the more load it carries between supports. A standard 1.5-inch B deck is the workhorse for typical bar-joist spacing, but when your designer pushes the supports farther apart, B deck runs out of capacity. 3 inch roof deck picks up where B deck stops.
That’s why N deck shows up on the biggest roofs in the country. It’s built for distance and weight, and it does both jobs with less supporting steel underneath. If you want the full breakdown of every profile we carry, our roof deck page covers the whole lineup, including N.
Why the Deep Rib Matters
The 3-inch rib delivers high section modulus and moment of inertia. In plain terms:
- Longer spans. N deck reaches across wider joist or purlin spacing than 1.5-inch profiles, so you frame fewer supports.
- Heavier loads. The deep rib handles greater roof live and dead loads, including snow, mechanical units, and ballast.
- Less structural steel. Fewer joists and purlins mean lower framing cost and faster erection.
- Stiffer diaphragm. N deck contributes strong diaphragm action for lateral loads when detailed per Steel Deck Institute
When to Specify N Deck
N deck isn’t the right call for every roof, and we’ll tell you straight when a B or C profile makes more sense. But for the right project, nothing else competes. Reach for long span roof deck when you’re dealing with:
- Big-box retail and warehouses with wide bays and long joist spacing.
- Distribution and fulfillment centers where open floor area and heavy rooftop equipment are the norm.
- Arenas, gymnasiums, and event centers with large clear spans.
- Manufacturing and industrial plants carrying heavy mechanical or process loads.
- Any roof where the structural engineer has pushed column spacing wide to keep the floor open.
If your drawings show purlin or joist spacing that B deck can’t make, that’s your signal. The deeper profile lets you keep the same panel thickness while covering far more distance.
N Deck Specifications and Gauges
Choosing the right N deck gauge for your span is the single most important decision in the order, and it’s the one we help with most. Spec too light and the deck deflects or fails the load check. Spec too heavy and you’ve paid for steel you didn’t need. Here’s how the standard offerings line up.
| Specification | Type N Roof Deck |
| Rib depth | 3 inches (deepest standard roof deck) |
| Coverage width | ~24 inches |
| Available gauges | 22, 20, 18, 16 |
| Galvanized coating | G60 (indoor / dry), G90 (outdoor / corrosive) per ASTM A653 |
| Finish options | Galvanized or painted |
| Steel origin | USA-made |
| Governing standards | Steel Deck Institute (SDI) |
| Common use | Long-span commercial & industrial roofs |
A few notes on reading that table:
- Gauge drives capacity. Lower gauge numbers mean thicker steel. A 16-gauge N panel carries more and spans farther than a 22-gauge panel of the same profile.
- Coating follows environment. Use G60 for interior, dry conditions. Step up to G90 for exterior exposure or corrosive settings, both per ASTM A653. Painted finishes are available when the project calls for them.
- Standards keep it honest. Our N deck is manufactured to SDI standards, and the base steel meets the relevant ASTM and AISI material requirements.
N Deck vs. B Deck at a Glance
Buyers often ask us whether they can stretch B deck to avoid switching profiles. Sometimes yes, often no. Here’s the simple contrast.
| Factor | B Deck (1.5″) | N Deck (3″) |
| Rib depth | 1.5 inches | 3 inches |
| Span capability | Standard joist spacing | Wide, long spans |
| Load capacity | Typical roof loads | Heavy roof loads |
| Supports needed | More joists/purlins | Fewer joists/purlins |
| Best for | Most commercial roofs | Large-span industrial roofs |
When the numbers favor N, switching profiles almost always saves money on the structure as a whole, even though the deck itself is deeper. Fewer supports add up fast.
Don’t Forget N Deck Closures and Accessories
A deep rib leaves big openings at the eaves, ridges, and panel ends, and those gaps invite air, pests, and weather if you leave them open. That’s why nearly every N deck order pairs with N deck foam closures, plugs, and strips shaped to match the 3-inch profile exactly.
We stock closures sized for N deck so you’re not jamming a B-deck closure into a 3-inch rib and hoping it seals. Closures matter for energy performance, fire detailing, and keeping critters out of the assembly. Browse our foam closure options and the rest of our accessories to round out the order, including fasteners and trim that ship right alongside the deck.
What to Look for in an N Deck Supplier
Not every metal supply house keeps deep-rib deck on hand, and a special order can stall a job for weeks. When you’re sourcing a steel roof deck supplier for N deck, here’s what actually matters.
Real Inventory, Not a Catalog Promise
N deck is a specialty profile. A supplier that “can get it” isn’t the same as one that has it stacked and ready. We keep N deck in multiple gauges in our Eagan yard so your order ships fast instead of sitting in someone’s procurement queue.
Cut-to-Order Lengths
Roofs aren’t built in standard increments. We cut N deck to your exact lengths, which cuts field waste and speeds installation. You get panels that fit the framing, not panels your crew has to trim on the deck.
Same-Day or Next-Day Shipping and Pickup
When the structure is up and the crew is staged, the deck can’t be the bottleneck. We offer same-day or next-day shipping and local pickup so the roof keeps moving. Quick turnaround is the difference between a productive week and a stalled one.
Expert Sizing Help
This is where experience earns its keep. Send us the span and the load and we’ll help confirm the right gauge before you commit. We’ve sized N deck for warehouses, distribution centers, and big-span industrial roofs, and we’d rather catch a gauge issue at the quote stage than on the jobsite.
USA-Made Steel and Accurate Quotes
Our deck is USA-made, manufactured to SDI standards, with base material meeting ASTM and AISI requirements. And when we quote a job, the number is real, itemized, and includes the closures and accessories you’ll actually need. You can see the full product range here or download our deck list to spec it out.
Why Contractors Choose Keystar Industries
We’re locally owned and operated, right at 1920 Shawnee Road in Eagan, MN. That means you’re talking to people who know the product, not a call center reading from a screen. We carry the full roof deck family, composite deck, form deck, accessories, and rentals, so most jobs get sourced from one place.
The pitch is simple. We stock USA-made N deck, cut it to your dimensions, ship it same-day or next-day, and help you nail the gauge before you order. For a deep-rib roof on a tight schedule, that combination is hard to beat.
Frequently Asked Questions
What is Type N roof deck used for?
Type N roof deck is a deep-rib steel panel with a 3-inch rib used on long-span, heavy-load roofs. You’ll find it on big-box stores, warehouses, distribution centers, arenas, and industrial buildings where wide column spacing or heavy roof loads make shallower profiles impractical.
How far can N deck span compared to B deck?
N deck spans significantly farther than 1.5-inch B deck because its 3-inch rib gives much higher section properties. That lets you space joists and purlins wider and use fewer of them. Exact spans depend on gauge and load, so send us your numbers and we’ll confirm the right setup.
What gauges does N deck come in?
Standard N deck comes in 22, 20, 18, and 16 gauge. Lower gauge numbers mean thicker steel and higher capacity. We stock multiple gauges and help you match the right one to your span and load.
Should I order G60 or G90 galvanized N deck?
Use G60 for interior, dry environments and G90 for exterior exposure or corrosive conditions, both per ASTM A653. Painted finishes are also available. If you’re unsure, tell us the application and we’ll recommend the right coating.
Do you stock N deck foam closures?
Yes. We stock foam closures, plugs, and strips shaped specifically for the 3-inch N deck profile. They seal the deep ribs at eaves, ridges, and panel ends to keep out air, weather, and pests, and we ship them right alongside your deck order.
How fast can I get N deck from Keystar?
We keep N deck in stock at our Eagan, MN yard and offer same-day or next-day shipping and pickup, with cut-to-order lengths. Request a quote or call us and we’ll tell you exactly what’s available and when it can be on your job.
Get a Fast, Accurate N Deck Quote
If you’ve got a long-span roof on the boards, let’s get the right deck heading your way. We’ll confirm the gauge, cut it to length, add the matching N deck closures, and ship it fast.
Request a quote or call us at (651) 256-0008. You can also contact our team with your span and load, and we’ll help you spec the right N deck the first time.