How G60 and G90 Galvanized Coatings Extend Type B Metal Deck Life in Florida
We offer G60 G90 Type B metal deck corrosion protection and installation services in Miami Florida for coastal and humid-climate commercial roofing and reroof projects
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Summary
- G90 offers stronger corrosion resistance than G60
- Galvanized zinc provides barrier and sacrificial protection
- Proper installation and maintenance maximize lifespan
Florida projects demand materials specified for high humidity and salt exposure. G60 and G90 galvanized coatings are industry standards that add barrier and sacrificial protection to Type B metal deck, slowing corrosion and extending service life. Miami Metal Deck evaluates exposure, code, and lifecycle cost to recommend the right coating for your project.
Why galvanized coatings matter in Florida
Galvanized coatings protect structural steel in two ways. First, the zinc layer forms a durable barrier that isolates steel from moisture and oxygen. Second, zinc provides galvanic or sacrificial protection where the zinc corrodes preferentially to the underlying steel, limiting section loss. Standards such as ASTM A653 define coating grades and help specifiers match material to environment.
G60 and G90 refer to nominal zinc coating weights under ASTM standards, roughly 0.60 oz per square foot and 0.90 oz per square foot total. Higher zinc weight means thicker coating and slower corrosion rates. In Florida's humid, often marine, environments G90 is commonly specified for Type B metal deck when long service life and reduced maintenance are priorities.
Real world lifespan and performance
Lifespan varies with exact exposure, maintenance, and design details. In moderate inland humid zones G60 can provide measurable decades of service when properly detailed; in coastal or high-salt settings G90 significantly delays perforation and section loss. Use ISO 9223 or local corrosivity maps together with ASTM guidance to estimate expected service life for your site.
Durability requires proper detailing and installation. Seal trim and flashings, protect cut edges, and perform approved repairs per ASTM A780. Avoid incompatible contact with copper or treated wood; use isolation barriers where necessary. When painting galvanized surfaces, use conversion coatings or compatible primers to improve adhesion and extend protection.
Miami Metal Deck differentiators
We source certified galvanized deck meeting ASTM A653 grades and work with fabricators to ensure G90 options where specifications call for it. Our field teams follow best practices for handling, cutting, and edge treatment to preserve the coating. We document material traceability, provide inspection reports, and align installations to local codes and coastal requirements.
Specifying G90 for Type B metal deck raises upfront material cost but reduces life cycle repair and replacement risk in Florida. For commercial owners this translates to lower downtime, fewer leak claims, and better long term ROI. Miami Metal Deck provides project-level recommendations that balance budget, performance, and warranty considerations.
Choosing the right coating for your project
Select the coating based on exposure category, expected service life, and maintenance plan. For inland projects G60 may be economical; for coastal or high humidity projects prioritize G90 and proper detailing. Miami Metal Deck evaluates site conditions and specifies the appropriate galvanized grade, fabrication practices, and repair protocols to maximize the long term performance of your Type B metal deck.