What Material Specs Should Type B Metal Deck Meet in Florida?
Our 1.5" Type B deck is ASTM A653 structural steel with a minimum yield strength of 50 ksi, galvanized G60 or G90, in 22, 20, 18 and 16 gauge, with painted and vented options. That is the standard specification Florida engineers write for roof deck. Coastal projects typically choose G90. We supply it cut to length.
How to write the specification
- Profile: 1.5" wide rib (Type B), 36" coverage, 6" rib spacing.
- Steel: ASTM A653 structural steel, Fy = 50 ksi.
- Coating: G60 or G90 galvanized; G90 for coastal or humid exposure.
- Gauge and design thickness per the deck schedule.
- Options: painted underside, vented for insulating fill.
- Design to ANSI/SDI RD-2017 and SD-2022.
Why 50 ksi matters
Higher yield strength raises bending capacity for the same thickness, which is reflected in the catalog load tables. Do not mix lower-strength deck into a design based on 50 ksi tables. Ask us whether mill certificates are available for your order if the project requires them.
Order to the spec
Send your specification section and deck schedule and we will quote material that matches each line.
1.5" Type B material data (catalog)
| Gauge | Design thickness (in) | Fy (ksi) | Weight (psf) |
|---|---|---|---|
| 22 | 0.0295 | 50 | 1.6 |
| 20 | 0.0358 | 50 | 2.0 |
| 18 | 0.0474 | 50 | 2.6 |
| 16 | 0.0598 | 50 | 3.0 |
Related Questions
What does G90 mean on a deck specification?
G90 is a zinc coating weight designation under ASTM A653 for hot-dip galvanized sheet. A G90 coating carries more zinc than G60, so it lasts longer in corrosive exposure. For coastal Florida, humid interiors or roofs at risk of moisture, engineers commonly specify G90. We supply both.
Is design thickness the same as minimum thickness?
The catalog lists design thickness of the base steel, used in the structural calculations: 0.0295" for 22 gauge to 0.0598" for 16 gauge. The coating is not counted. Delivered material may vary within the allowed tolerance, which the SDI standards address. If your project needs mill certificates, ask us what is available for your order.