Coastal Aluminium Windows: A Specifier’s Guide (2026)
How to Choose Aluminium Windows for Coastal Homes
Coastal aluminium windows face two enemies that inland windows never meet: salt spray and sand abrasion. Salt accelerates coating degradation and hardware corrosion; wind-driven sand acts as an abrasive that wears powder-coat edges and grinds on hardware. Getting coastal aluminium windows right is therefore not about the frame shape—it is about the specification written on the order.
Coastal Aluminium Windows: Quick Specification Summary
The five decisions that determine coastal window lifespan:
- Powder coat specification: AAMA 2605 minimum (60 µm TGIC polyester); FEVE fluoropolymer (80 µm) for severe coastal exposure.
- Hardware material: 316 stainless steel hinges and rollers (not 304, never zinc-plated).
- Thermal break: PA66 GF25, minimum 24 mm, continuous—including through drainage points.
- Drainage system: Protected weep points (3+ per sash); self-draining track.
- Glazing seal: Warm-edge spacer (TPS/SuperSpacer); high-modulus silicone secondary seal.
Red flags to avoid: Any coastal aluminium window quoted without coastal-grade coating documentation, or fitted with 304 stainless or zinc-plated hardware in a salt-air application.
Why Coastal Environments Are Different
Coastal sites create accelerated degradation through three mechanisms that inland sites do not.
Salt Spray (Chloride Attack)
Seawater aerosol carries sodium chloride (NaCl) particles that settle on exterior surfaces. When these dissolve in surface moisture, they form an electrolyte that drives electrochemical corrosion—the same family of process that rusts steel. Aluminium oxide, the natural protective layer on aluminium, is stable in neutral conditions but can be attacked by chloride at high humidity.
AAMA 2605 coating performance: AAMA 2605 mandates 3,000-hour ASTM B117 salt spray testing—the coated panel must show less than 1/16 inch undercutting from the scribe mark after 3,000 hours. That translates to roughly 15–25 years of coastal service life for TGIC polyester at 60 µm.
UV Exposure
Coastal sites typically receive 20–30% more UV radiation than inland locations, thanks to reduced cloud cover and reflection off water and sand. UV degrades powder-coat binders through photo-oxidation. AAMA 2605 and FEVE coatings are UV-stable; budget polyester coatings (AAMA 2604 or below) degrade noticeably faster under coastal UV.
Sand Abrasion
Wind-driven sand is a mild but relentless abrasive. It does most damage to coating edges (where the film is thinnest) and to insect-screen mesh, which can be worn through in 3–5 years unless you specify aluminium or stainless steel mesh.
The 5 Specification Decisions for Coastal Aluminium Windows
Decision 1: Powder Coat — AAMA 2605 or FEVE?
AAMA 2605 (TGIC polyester, 60 µm minimum):
- 3,000-hour ASTM B117 salt spray rating
- Gloss retention: ≥50% at 10 years in severe coastal exposure
- Service life estimate: 15–25 years in coastal environments
- Cost: standard coastal specification
- Best for: properties 500–2,000 m from the coast, mild coastal conditions
FEVE fluoropolymer (80 µm minimum):
- 5,000+ hour ASTM B117 salt spray rating
- Gloss retention: ≥90% at 10 years in severe coastal exposure
- Service life estimate: 25–35 years in coastal environments
- Cost: 25–40% premium over AAMA 2605
- Best for: properties within 200–500 m of the coast, beachfront, severe storm zones
Red flag: Any supplier quoting coastal use on AAMA 2604 (architectural medium-performance) or below. AAMA 2604 is rated for only 1,500-hour B117 and 5-year gloss retention—it is built for inland architectural use, not coastal.
Starveil coastal systems: Starveil’s standard coastal specification is AAMA 2605. FEVE fluoropolymer is available as an upgrade for beachfront and severe coastal applications.
Decision 2: Hardware Material — 316 Stainless vs 304 Stainless
Hinges, rollers, locking mechanisms, and handles in coastal aluminium windows must be 316 stainless steel (AISI 316 / EN 1.4401).
Why 316 specifically? 316 stainless contains 2–3% molybdenum, which dramatically improves chloride resistance over 304 stainless. In ASTM B117 salt spray testing, 304 shows visible pitting after about 200 hours; 316 shows no pitting at 1,000 hours.
Common budget shortcut: Zinc-plated steel hardware. In coastal air, zinc plating fails within 2–5 years and the underlying steel then corrodes fast. Never accept zinc-plated hardware in a coastal specification.
Hardware specification checklist:
- Hinges: 316 stainless steel, minimum 3 per sash for windows above 1,200 mm tall
- Rollers: 316 stainless ball bearings, Class 3 per EN 13451 minimum
- Locking hardware: 316 stainless or marine-grade aluminium
- Handles: Marine-grade aluminium or 316 stainless; avoid zinc die-cast
Decision 3: Thermal Break at the Coastal Threshold
Coastal thermal-break requirements match inland ones—PA66 GF25, minimum 24 mm wide, continuous. The thermal break does not govern corrosion; it governs condensation and energy performance.
But there is one coastal-specific trap: the thermal break must not be interrupted at drainage points. Some budget systems delete the thermal break at the drainage slot to simplify manufacturing, creating a thermal bridge there—cold outside air conducts through the aluminium at the slot, causing condensation on the interior frame at that exact point.
Starveil coastal design: All Starveil coastal frames use a continuous PA66 GF25 thermal break with the drainage channel routed through the polyamide section, not through the aluminium—eliminating the thermal bridge at the drainage point.
Decision 4: Drainage System Design
Coastal sites bring higher rainfall intensity (coastal storms) and higher wind pressure (open exposure). Your drainage must handle both.
Key drainage requirements:
- Multiple weep positions: minimum 3 drainage points per sash, not one central drain
- Weep guard protection: drainage slots protected by a snap-in cover so sand and salt crust cannot block the drain during installation
- Self-draining track: on sliding doors, the track must shed water outside without pooling
- High-pressure water resistance: specify windows tested to EN 12208 at minimum 600 Pa (Class 4A) for coastal use
Decision 5: Glazing Seal in Coastal Conditions
Coastal humidity accelerates degradation of the double-glazed unit’s secondary seal (the silicone bonding glass to spacer bar). Warm-edge spacers (TPS/SuperSpacer) cut the thermal-stress differential that causes seal fatigue.
Recommended coastal glazing specification:
- Spacer: warm-edge thermoplastic spacer (TPS/SuperSpacer)—not an aluminium spacer bar
- Primary seal: PIB polyisobutylene, minimum 4 mm thickness
- Secondary seal: high-modulus structural silicone, minimum 5 mm thickness
- Glass option: laminated or tempered glass for impact resistance in storm-prone coastal zones (ASTM E1996 compliant where required)
Coastal Distance Zones and Specification
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Distance from Coast
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Recommended Specification
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|---|---|
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Within 200 m (beachfront)
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FEVE fluoropolymer 80 µm, 316 SS hardware, enhanced seal
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200–500 m
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AAMA 2605 60 µm, 316 SS hardware, warm-edge spacer
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500–1,000 m
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AAMA 2605 60 µm, 316 SS hardware (304 acceptable in sheltered spots)
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1,000–2,000 m
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AAMA 2605 (2604 acceptable here, as exposure is no longer strictly coastal), standard hardware with coastal consideration
|
Before You Order: Coastal Specification Checklist
- Powder coat confirmed in writing (AAMA 2605 or FEVE, µm thickness stated)
- Hardware material confirmed (316 stainless, not zinc-plated or 304)
- Thermal break confirmed (PA66 GF25, minimum 24 mm, continuous)
- Drainage system: 3+ weep points with protected weep guards
- Water penetration rating confirmed (minimum EN 12208 Class 3A; Class 4A preferred)
- Glazing seal confirmed (warm-edge spacer, silicone secondary seal)
- Insect screen mesh: aluminium or 316 stainless (not fibreglass or nylon)
- Structural certification for your wind load zone confirmed
Why Choose Starveil?
Starveil has supplied coastal aluminium windows and doors to 42 countries, including extensive Gulf Coast, Mediterranean, Pacific coastal, and Caribbean projects. Our documented coastal installations confirm AAMA 2605 specification holds coating integrity at 20+ years without replacement.
Coastal Aluminium Windows: Frequently Asked Questions
How long do aluminium windows last in coastal environments?
With AAMA 2605 (60 µm), coastal aluminium windows last 15–25 years before re-coating. With FEVE fluoropolymer (80 µm), the coating holds integrity for 25–35 years. The aluminium frame itself does not corrode with proper coating—it is effectively permanent.
What coating is needed for coastal aluminium windows?
AAMA 2605 TGIC polyester, minimum 60 µm dry film thickness, is the minimum acceptable coastal specification. FEVE fluoropolymer at 80 µm is recommended for severe coastal exposure (within 500 m of the ocean).
Will 304 stainless steel hardware work in coastal environments?
304 stainless is marginal by the sea—it shows pitting within about 200 hours in ASTM B117 salt spray testing. 316 stainless is the correct choice for coastal hardware, holding visible corrosion resistance through 1,000+ hours of salt spray.
Do coastal windows need impact-resistant glazing?
In hurricane-prone coastal zones (Florida, Caribbean, Gulf Coast), building codes require impact-resistant glazing in specific zones. ASTM E1996 governs impact requirements and AAMA 506 the test procedures. Starveil supplies impact-rated systems for all major coastal wind zones.
What is the difference between AAMA 2604 and AAMA 2605 for coastal use?
AAMA 2604 is architectural medium-performance (1,500-hour B117, 5-year gloss retention), designed for inland use. AAMA 2605 is architectural high-performance (3,000-hour B117, 10-year gloss retention), built for severe conditions including coastal. Always specify AAMA 2605 for coastal applications.
How do I maintain coastal aluminium windows?
Annually: rinse with fresh water to remove salt deposits, clean the track and drainage points, inspect hardware for salt build-up and lubricate with dry PTFE lubricant. Every 5 years: a professional inspection of coating edges and hardware, touching up any stone chips or edge damage with AAMA 2605-compliant repair lacquer.
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