The Impact of Salt Spray on Roofing Fasteners & Materials

Salt doesn't just sit on surfaces—it actively attacks roofing components through multiple mechanisms:

The Corrosion Process

Salt spray deposits sodium chloride crystals on roofing surfaces. These crystals:

• Attract moisture – salt is hygroscopic, meaning it pulls water from humid air
• Create electrolyte solution – salt + water creates a corrosive electrolyte that accelerates metal oxidation
• Penetrate protective coatings – salt finds microscopic gaps in paint and galvanizing
• Cause galvanic corrosion – when dissimilar metals contact each other in salt presence, accelerated corrosion occurs

Components Most Vulnerable to Salt Damage

Perhaps the most dangerous salt spray damage is invisible: corroded fasteners that look fine but have lost most of their holding power.

How Fasteners Fail

Roofing nails in coastal environments undergo a predictable deterioration:

1. Galvanizing breach – salt penetrates the zinc coating through scratches or manufacturing gaps
2. Core corrosion begins – steel core starts rusting from the inside
3. Cross-section reduction – rust expands, but the nail shaft shrinks in effective diameter
4. Grip loss – corroded nail no longer grips wood fibers effectively
5. Sudden failure – during high winds, nail pulls through or snaps off

Signs of Fastener Corrosion

Unfortunately, fastener corrosion is hard to detect without removing shingles. However, some indicators suggest problems:

• Rust stains running down from under shingle tabs
• Shingles that lift easily at corners during inspection
• Visible rust on exposed nail heads (ridge caps, repairs)
• Multiple nail pops – corroded nails lose grip and work upward
• Shingle blow-off in moderate winds – healthy fasteners hold in 60+ mph

Fastener Lifespan by Location

Choosing the right materials for coastal environments can double or triple the lifespan of roofing components. Here's what we recommend for Myrtle Beach properties:

Fasteners and Nails

Flashing Materials

• Aluminum – excellent corrosion resistance, doesn't rust but can oxidize
• Copper – outstanding durability, develops protective patina
• Stainless Steel – best overall but higher cost
• Lead-Coated Copper – traditional choice for critical areas
• Galvanized Steel – avoid within 3 miles of ocean

Metal Roofing Systems

For coastal metal roofs, material selection is critical:

• Aluminum – naturally corrosion resistant, ideal for oceanfront
• Galvalume (aluminum-zinc alloy) – good coastal performance
• Zinc – excellent longevity, develops protective patina
• Painted steel – requires high-quality marine-grade coating
• Copper – ultimate durability, premium cost

Hardware and Accessories

• Vent caps – specify stainless or aluminum, not galvanized
• Gutter hangers – stainless steel or heavy aluminum
• Drip edge – aluminum minimum, preferably marine-grade
• Valley metal – aluminum or painted Galvalume
• Hurricane clips – galvanized with marine sealant or stainless

Regular maintenance is even more critical for coastal properties. Salt deposits accumulate continuously and accelerate damage when not removed:

Salt Removal and Cleaning

Inspection Focus Points

During coastal roof inspections, pay special attention to:

• Exposed metal components – look for rust, pitting, or white oxidation
• Flashing condition – check for corrosion, especially at overlaps
• Fastener condition – examine exposed nails for rust
• Sealant integrity – salt degrades caulks and sealants faster
• Gutter hardware – check hangers and connections for corrosion

Protective Treatments

Several treatments can extend component life in salt environments:

• Rust inhibitor sprays – apply to exposed metal hardware annually
• Marine-grade sealants – use only salt-resistant caulks and sealants
• Protective coatings – some metal components benefit from additional coating
• Zinc anodes – can protect nearby metals through sacrificial corrosion

When to Replace vs. Treat