2026-09-18Aluminium windows can suit coastal homes, but they are not immune to corrosion. Aluminium does not form iron rust in the way steel does; salt exposure can still damage aluminium surfaces and associated hardware. Specify the finish, fasteners, drainage and maintenance for the actual location.
The sheltered side of a coastal house may collect deposits that rain rarely washes away. A balcony opening, a window under a deep overhang and an exposed facade can therefore need different attention. Give the supplier photos and an honest description of the exposure.
Specify more than a colour
A colour chip tells you little about pretreatment, coating quality or corrosion protection. Request the coating specification and applicator details. Ask which coastal conditions the proposed finish is intended for and what documentation supports the claim.
QUALICOAT UK and Ireland’s maintenance guidance describes the importance of pretreatment and appropriate care for coated aluminium. Its discussion of Seaside preparation is a reason to ask precise questions, not to assume a supplied frame is certified or corrosion-proof.
Check the small parts as carefully as the frame
List hinges, rollers, screws, locking components, handles and screen fittings. The visible aluminium frame may be only one part of the exposure problem. Ask the system supplier to specify compatible components and explain how dissimilar materials are separated where required.
| Item | Request in writing |
|---|---|
| Frame finish | Specification, applicator and exposure suitability |
| Hardware | Materials, compatibility and replacement availability |
| Installation | Drainage, sealant compatibility and protection during building work |
| Cleaning | Approved products, frequency and hard-to-reach areas |
| Warranty | Coastal exclusions, maintenance records and claim process |
Agree a maintenance plan you can actually follow
Ask how often the supplier recommends cleaning in your exposure; do not substitute a universal interval. Use its approved cleaning products and avoid improvised abrasive or aggressive chemical treatments. Plan safe access to the outside faces, sill outlets and sheltered corners.
During construction, protect finishes from wet trades and clean contamination using the approved method. At handover, photograph the original condition. Keep a simple record of cleaning and repairs, including damaged coating, sticking hardware or changes around the drainage outlets.
The installation scope guide helps assign these tasks. If replacing existing corroded units, ask the surveyor to identify why they deteriorated before choosing a replacement solely by frame colour.
Frequently asked questions
Will aluminium rust beside the sea?
It will not develop iron rust as an aluminium surface, but corrosion can still occur and steel hardware may rust. Use the more useful question: which complete frame, coating and hardware package is suitable for this exposure, and what care does it require?
Does a marine-grade label settle the choice?
No. Ask what the phrase means in the quotation: a particular alloy, pretreatment, coating or hardware package. Request the technical specification and warranty conditions. A broad marketing label does not identify every component in the opening.
Can damaged finishes simply be touched up?
Ask the supplier to assess the damage and approve a repair method. A cosmetic touch-up may not restore the original protection or appearance. Include the exposure and photographs in your project enquiry before accepting a repair proposal.
