Metal deck is sold by profile, and the names (1.5B, Type F, 3N, composite, form) can confuse anyone new to specifying steel deck. This guide explains the main deck types and what each is used for.
The Two Main Families: Roof Deck and Floor Deck
Roof deck supports roofing, insulation and roof loads. Floor deck is designed to receive structural concrete. Floor deck splits again into non-composite (form) deck and composite deck.
Roof Deck Types: A, B, F and N
Roof deck profiles are labeled by a letter and by depth:
| Type | Typical depth | Rib | Typical use |
|---|---|---|---|
| Type B | 1.5" | Wide rib | The most common roof deck for commercial and industrial buildings |
| Type F | 1.5" | Intermediate rib | Roof applications where an intermediate rib is specified |
| Type A | 1.5" | Narrow rib | Roof applications where a narrow rib is specified |
| Type N | 3" | Deeper profile | Longer roof spans |
Cutting Edge Decking supplies 1.5B and 3NJ-32 roof deck. 1.5B is 1.5 inches deep with a 36-inch cover width. 3NJ-32 is 3 inches deep with a 32-inch cover width. Read more in What Is 1.5" B Roof Deck?
Floor Deck Types: Non-Composite and Composite
- Non-composite (form) deck is permanent formwork. The slab carries the load itself. See What Is Form Deck?
- Composite deck bonds with the concrete through embossments, so deck and slab work together. See Composite vs. Non-Composite Deck.
Both come in 1.5-inch, 2-inch and 3-inch depths with a 36-inch cover width.
Reading a Deck Name
| 1.5B | 1.5-inch deep, Type B (wide rib) roof deck |
| 1.5NC / 2NC / 3NC | 1.5, 2 or 3-inch non-composite (form) floor deck |
| 1.5CF / 2CF / 3CF | 1.5, 2 or 3-inch composite floor deck |
| 3NJ-32 | 3-inch deep roof deck, 32-inch cover width |
Dimensions and weights for each are in our sizes, dimensions and weights guide.
Frequently Asked Questions
What is the difference between Type B and Type F roof deck?
Both are 1.5-inch-deep roof deck profiles. They differ in rib width: Type B has a wide rib and Type F has an intermediate rib. Type B is the most common roof deck profile in commercial and industrial buildings.
What is Type N roof deck?
Type N is a deeper roof deck profile, typically 3 inches deep, used where longer roof spans are needed. Cutting Edge Decking supplies 3NJ-32, a 3-inch-deep roof deck with a 32-inch cover width.
What is the difference between roof deck and floor deck?
Roof deck supports roofing, insulation and roof loads and is not designed to receive structural concrete. Floor deck is designed to receive concrete and is either non-composite (formwork only) or composite (bonded to the slab).
What does 1.5B mean?
1.5B means a 1.5-inch-deep Type B (wide rib) profile. It has a 36-inch cover width and ribs 6 inches on center.
Which metal deck type should I choose?
The structural engineer of record specifies the type, gauge and finish based on loads, spans and project requirements. A supplier can confirm which profiles are available and quote them.
Next Step
Once you know the profile your project calls for, use our quote request form or browse the steel deck products.
Frequently Asked Questions
What is the difference between Type B and Type F roof deck?
Both are 1.5-inch-deep roof deck profiles. They differ in rib width: Type B has a wide rib and Type F has an intermediate rib. Type B is the most common roof deck profile in commercial and industrial buildings.
What is Type N roof deck?
Type N is a deeper roof deck profile, typically 3 inches deep, used where longer roof spans are needed. Cutting Edge Decking supplies 3NJ-32, a 3-inch-deep roof deck with a 32-inch cover width.
What is the difference between roof deck and floor deck?
Roof deck supports roofing, insulation and roof loads and is not designed to receive structural concrete. Floor deck is designed to receive concrete and is either non-composite (formwork only) or composite (bonded to the slab).
What does 1.5B mean?
1.5B means a 1.5-inch-deep Type B (wide rib) profile. It has a 36-inch cover width and ribs 6 inches on center.
Which metal deck type should I choose?
The structural engineer of record specifies the type, gauge and finish based on loads, spans and project requirements. A supplier can confirm which profiles are available and quote them.