Type F Deck: The Intermediate Rib Steel Roof Deck Explained

When a roof spec calls for a Type F deck, it’s pointing to a specific member of the steel roof deck family: the intermediate rib profile. At Keystar Industries in Eagan, Minnesota, we stock and cut this profile to order, and we field questions about it almost every week. Buyers want to know how the Type F roof deck differs from its neighbors, when to use it, and how to match it to an existing roof. This guide answers all of that and shows you how to get the right deck shipped fast.

Before we go further, one quick clarification. The “F” in Type F roof deck refers to the intermediate rib structural profile, not to form deck (sometimes labeled “F-deck” in a forming context). Those are two different products with two different jobs. This page is about the intermediate-rib roof deck that serves as the structural base on commercial and industrial roofs.

What Is a Type F Deck?

A Type F deck is a corrugated steel roof deck with an intermediate rib width. In the standard roof deck lineup, rib width is the defining variable, and the family breaks down into three core profiles:

Type A — narrow rib
Type F — intermediate rib
Type B — wide rib (the most common)

The Type F sits right in the middle. Its rib opening is narrower than a Type B but wider than a Type A. That intermediate geometry gives you a useful balance between top bearing surface (the flat flutes the roofing system rests on) and rib spacing. It’s the kind of profile you reach for when the F pattern matches your roofing and insulation assembly, or when you’re matching deck that’s already on the building.

Like the rest of the standard roof deck family, the Type F profile uses a 1.5 inch nominal depth and 36 inch net coverage per panel. That keeps it interchangeable, dimensionally, with A, B, and the other 1.5″ profiles. The difference you care about is the rib shape, which is what determines fastening patterns, insulation board bearing, and how the membrane system lands on the deck.

Type F Roof Deck Specifications

We supply the intermediate ribbed roof deck in the gauges, finishes, and dimensions that the Steel Deck Institute standards call for. Here’s the snapshot most buyers ask us to confirm.

Specification	Type F Roof Deck
Profile / rib	Intermediate rib (F pattern)
Nominal depth	1.5 inches
Net coverage	36 inches
Gauges	22, 20, 18, 16
Galvanized finishes	G60 (indoor/dry), G90 (outdoor/corrosive)
Galvanizing standard	ASTM A653
Other finishes	Painted available
Steel origin	USA-made
Typical use	Commercial & industrial flat / low-slope roofs

A few notes on these specs. The gauge you choose drives load capacity and span — heavier gauges (16 and 18) carry more and span farther, while 20 and 22 suit lighter loads and tighter spans. The right gauge depends on your span, your loads, and the SDI load tables, so loop in your engineer if you’re unsure.

On finish, the rule of thumb is simple. Choose G60 galvanized for indoor or dry environments, and step up to G90 galvanized for outdoor or corrosive exposure, both per ASTM International standard A653. Painted finishes are also available when the deck is exposed to view or you have a specific coating requirement.

How Type F Compares to Type A and Type B

The fastest way to understand the intermediate rib is to see it next to its siblings. The whole roof deck family shares the same 1.5″ depth and 36″ coverage — the rib width is what changes.

Profile	Rib Width	Position in Family	Depth	Coverage
Type A	Narrow rib	Narrowest opening	1.5″	36″
Type F	Intermediate rib	Middle of the range	1.5″	36″
Type B	Wide rib	Widest opening (most common)	1.5″	36″

Type B is the workhorse most projects default to because of its broad availability and wide rib. Type A’s narrow rib offers more top bearing surface for certain assemblies. The Type F deck lands between them, which is exactly why it gets specified: it gives you the rib spacing and bearing balance that some roofing and insulation systems are designed around. For deeper structural spans, the family extends to the N deep rib profile, but that’s a different depth class entirely.

If you want the full breakdown of every profile we carry — A, B, C, F, and N — see our roof deck page, where each profile is laid out side by side.

When to Choose a Type F Deck

We don’t push customers toward the intermediate rib for its own sake. It’s the right call in specific situations, and here are the most common ones we see at Keystar.

Your roofing system specifies it: Some membrane and insulation assemblies are engineered for an intermediate rib spacing. When the manufacturer’s spec calls for the F pattern, that’s what you install.
You’re matching existing deck: Re-roofing or expanding a building that already has Type F roof deck? Matching the profile keeps the assembly consistent and the insulation boards bearing correctly across old and new sections.
You need a balance of bearing and rib spacing: When a wide rib is too open for your insulation board and a narrow rib is more bearing than you need, the intermediate rib threads the needle.
Your engineer’s load tables point to it: Sometimes the F profile, in a given gauge, is simply the cleanest fit for the spans and loads on the drawings.

The key word in all of this is match. Roof decks are not freely interchangeable across profiles — fastening patterns, insulation bearing, and membrane attachment all depend on the rib geometry. Getting the profile right the first time saves you from costly callbacks. If you’re not certain which profile you’re looking at, our team can help you identify it from a photo or a sample.

Where Type F Roof Deck Gets Used

The intermediate ribbed roof deck does the same fundamental job as the rest of the steel roof deck family: it’s the structural base that spans the open framing of a roof and supports everything above it. On a typical commercial or industrial flat or low-slope roof, the assembly stacks up like this:

Steel roof deck (your Type F panels) fastened to the joists or purlins
Insulation board laid over the deck
Membrane or roofing system as the weatherproof top layer

Because the deck is the foundation of that stack, the profile has to play nicely with the layers above it. That’s why the F pattern matters — it sets how the insulation boards bear and how the system attaches. You’ll find this deck on warehouses, manufacturing facilities, retail boxes, distribution centers, and similar structures across the Upper Midwest and beyond.

For more on the broader roof and floor systems we supply, our products page covers roof decking, composite, form, and accessories in one place.

Type F Deck Accessories and Foam Closures

A roof deck install rarely stops at the panels. The intermediate rib profile creates open flutes at the deck edges, eaves, and transitions, and those openings need to be closed off to keep the assembly tight. That’s where foam closures come in.

We stock F deck foam closure plugs and strips shaped to fit the intermediate rib profile. They seal the open rib ends to block air movement, keep out pests and debris, and support a clean, finished edge condition. Because they’re profile-specific, you want closures cut for the F pattern — not a generic shape that leaves gaps. Browse our foam closure options sized for Type F deck.

Beyond closures, we carry the fasteners, trim, and related items that round out a roof deck order. See the full lineup on our accessories page.

Why Buy Your Type F Deck From Keystar

We’re a locally owned and operated metal roof decking supplier based at 1920 Shawnee Road in Eagan, MN. We’ve spent years helping contractors, builders, and facility owners get the right deck on the truck without the runaround. Here’s what that means for your order.

USA-made steel. Every deck profile we supply, including Type F, is American-made steel deck.
Cut-to-order. We cut your panels to the lengths your job needs, so you’re not paying for waste or wrestling with field cuts.
Same-day / next-day shipping or pickup. When the schedule is tight, we move fast — ship it out or have it ready for pickup.
Real inventory. We keep profiles and gauges in stock so you’re not waiting weeks on a mill order.
Expert help. Not sure if your existing deck is Type A, F, or B? Send us a photo. We’ll help you confirm the profile before you commit.

Our standards follow the Steel Deck Institute, and we supply steel produced to the specifications backed by the American Iron and Steel Institute. When you order a 1.5 inch roof deck from us, you’re getting product that meets the industry baseline, cut and shipped on your timeline.

You can also download our deck list to compare profiles and gauges before you reach out.

Frequently Asked Questions

Is Type F deck the same as form deck?

No. The Type F roof deck is the intermediate rib structural roof profile. Form deck is a separate product used as a permanent form for concrete. The “F” labels are unrelated. If you need form deck, see our form deck page instead.

What is the difference between Type A, F, and B roof deck?

All three share a 1.5″ depth and 36″ coverage. The difference is rib width: Type A is narrow rib, Type F is intermediate rib, and Type B is wide rib (and the most common). The right one depends on your roofing system and any existing deck you’re matching.

What gauges does Type F roof deck come in?

We supply the intermediate ribbed roof deck in 22, 20, 18, and 16 gauge. Heavier gauges carry more load and span farther. Your engineer’s load tables and span requirements determine the right gauge.

Should I order G60 or G90 galvanized?

Choose G60 for indoor or dry environments and G90 for outdoor or corrosive exposure, both per ASTM A653. Painted finishes are also available. If you’re unsure, tell us the exposure and we’ll recommend the right finish.

Can Keystar match my existing roof deck profile?

Yes. Send us a photo or a sample and we’ll help confirm whether you have Type A, F, B, or another profile, then cut and ship the matching deck. Getting the profile right keeps your insulation and membrane system bearing correctly.

How fast can I get Type F deck?

We offer same-day or next-day shipping or pickup on stocked profiles, cut to your order. Request a quote or call us and we’ll confirm availability and lead time.

Get Your Type F Deck Quote

Need the intermediate rib profile cut to length and on the truck fast? We’ve got USA-made Type F roof deck in stock, cut to order, and ready to ship same-day or next-day from Eagan, MN. Request a quote or call (651) 256-0008 and our team will get you the right profile, gauge, and finish for your job. You can also contact us with a photo if you need help identifying your existing deck.