Do Aluminium Windows Rust? Everything You Need to Know

If you're weighing up aluminium windows for your home, there's a good chance one question has crossed your mind: what happens when they get wet? It's the UK, after all… rain is basically a given, and we’ve all dealt with that dreaded garden furniture rust before, so why would metal windows be any different?

So do aluminium windows rust? And if not, how do they hold up over time in our varied climate? The short answer is no, aluminium windows don't rust, but there's a bit more to the story than that.

In this guide, we'll walk you through how aluminium handles moisture and corrosion, how long you can expect your windows to last, and what little maintenance they actually need to keep performing well year after year.

Does Aluminium Rust Easily?

No, and the reason is actually quite simple. Rust is a process that only affects iron-based metals. When iron or steel is exposed to moisture and oxygen, it undergoes a chemical reaction that produces iron oxide: that’s the reddish-brown flaking we all know as rust. Aluminium doesn't contain iron, so that reaction simply can't happen.

That's one of the key reasons aluminium has become such a popular material for windows, doors, and other external building products. You're not going to come home one day to find your window frames flaking and deteriorating the way old steel-framed windows sometimes can.

So if you've been putting off aluminium because of rust worries, you can cross that one off the list for starters.

What Happens to Aluminium Instead of Rusting?

Ok, so aluminium does react with oxygen, but in a very different (and actually quite clever) way. When aluminium is exposed to air, it forms a thin layer of aluminium oxide on its surface. This process is called oxidation, and unlike rust on steel, it doesn't weaken the material or cause it to deteriorate.

Instead, that oxide layer acts as a natural barrier, basically sealing the aluminium underneath from any further exposure to the elements. It's self-repairing too: if the surface is scratched or damaged, a new protective layer forms almost immediately. This is what makes aluminium so naturally resistant to the elements, without needing any additional treatment to stay that way.

So essentially, your aluminium windows look after themselves. All they need from you is a clean now and again.

Are Aluminium Windows Resistant to Corrosion?

Yes, and highly so, in fact. Aluminium's natural oxide layer makes it one of the most corrosion-resistant materials available for windows and external joinery.

In practice, that means aluminium windows hold up well in a wide range of environments, from standard suburban homes to more challenging coastal settings where salt air can accelerate deterioration in other materials.

How Aluminium Handles UK Weather

Our lovely British climate is famously unpredictable (rain, wind, temperature swings, the occasional bit of frost, unpredictable hail). Aluminium takes all of it in its stride.

Unlike timber, aluminium window frames won't warp, swell, rot, or crack as moisture and temperature change through the seasons. Unlike steel, aluminium won't corrode or rust when it gets wet. And, unlike uPVC, it maintains its structural integrity in both high heat and cold without becoming gradually more brittle over time.

For a practical sense of how aluminium performs in specific settings, it's worth reading our blog on why aluminium windows are a smart choice for kitchens, an environment where condensation, steam and moisture are a daily reality.

The Role of Powder-Coated Finishes

While aluminium's natural properties are already impressive, most modern aluminium windows come with a powder-coated finish that adds an extra layer of protection (as well as a huge amount of design flexibility).

Powder coating is a dry finishing process during which electrostatically charged powder is applied to the aluminium frame and cured under heat. The result of that technical process is a smooth, hard, durable surface that's resistant to chipping, scratching, fading and UV damage. It's the reason black aluminium windows and anthracite grey frames can hold their colour for decades without looking tired or worn.

The coating also gives aluminium windows a much wider colour range than many other window materials, so if you have a specific shade in mind, there's a very good chance it exists.

How Long Do Aluminium Windows Last?

This is where aluminium really earns its reputation as a trusted member of the UK DIY and buildings scene. A well-made aluminium window, properly installed and given basic care, can last 40 years or more, with many manufacturers citing lifespans of up to 45 years as a realistic expectation. Some installations comfortably outlast that, with proper cleaning maintenance and favourable conditions.

The longevity of aluminium windows comes down to a few things working together: aluminium's natural corrosion resistance, the durability of powder-coated finishes, and the fact that the material doesn't degrade in the way timber or cheaper plastics can. It doesn't absorb moisture, it doesn't rot, and it doesn't rely on regular repainting to hold itself together.

From a value perspective, it's worth thinking about the total cost of ownership rather than just the upfront price. A window that lasts 40 years with minimal maintenance is a very different proposition to one that needs replacing in 15–20. It’s similar to what we’ve discussed in our aluminium door prices guide: that same buy-once, buy-right logic applies equally to windows.

How to Maintain Aluminium Windows

One of the most appealing things about aluminium windows is how little they ask of you. There's no sanding or repainting needed, and no annual treatments required; just a small amount of routine upkeep to keep everything looking and functioning at its best.

Cleaning Aluminium Frames

As well as looking good, aluminium windows are mercifully low maintenance. Cleaning aluminium window frames is about as straightforward as it gets.

All you need is warm water, a mild washing-up liquid, and a soft cloth or sponge. Work carefully around the frame to dislodge any dirt or debris, rinse off with clean water, and dry with a soft cloth to avoid any water marks.

Avoid using anything abrasive for your cleaning (scouring pads, wire wool, or harsh chemical cleaners) as these can scratch or dull the powder-coated finish. For stubborn marks that don’t budge easily, a dedicated uPVC or aluminium frame cleaner (widely available at DIY stores) will do the job without causing damage. You might just need a smidge more elbow grease, but it’s worth it!

Most homeowners find a thorough clean two or three times a year is more than sufficient, though a quick wipe down after particularly dirty weather (including windstorms and snow) never goes amiss.

Simple Maintenance Tips

Beyond cleaning, there are a few easy habits that will help your aluminium windows perform well for the long haul:

• Check the window seals and weatherstripping once a year, particularly heading into winter. If you notice draughts or condensation between the panes, it may be time to replace the seals, which is a job most installers can do quickly and inexpensively.
• Keep the tracks and channels clear. Dirt and debris can build up in the sliding or opening channels over time, which can affect how smoothly the window operates. A soft brush or a vacuum with a narrow nozzle works well here to scoop up any dust.
• Lubricate moving parts like hinges, handles, and locking mechanisms with a light silicone-based lubricant every year or so to keep everything operating smoothly. Avoid oil-based products, which can attract dust and grime.
• Check for any chips or scratches in the powder coating. Small areas of damage like scratches are easy to touch up with a colour-matched aluminium touch-up paint; leaving them unattended for a long time (even if you think they can’t be noticed) can allow surface oxidation to build up beneath the coating.

  Sounds simple, right? That's genuinely about the extent of what it takes to keep aluminium windows clean. Compared to timber, which can demand a full repaint every few years, aluminium is about as low-maintenance as external joinery gets.

How Much Do Aluminium Windows Cost?

In general, the cost of aluminium windows sits a little above uPVC in terms of price, but the gap has narrowed considerably as the material has become more mainstream. For most UK homeowners, here's a rough guide to what to expect:

Standard casement aluminium window (supply only): approximately £300–£800* per window, depending on size and glazing specification

Fully fitted, including installation: typically, £600–£1,500* per window for a standard opening

Larger or more complex styles (tilt and turn, bay or bow windows, or bespoke sizes) can run to £1,500–£3,000+* fitted

A full house replacement (say, 8–12 windows): ballpark £6,000–£15,000* fitted, depending on specification

The biggest factors affecting aluminium window price are size, glazing (double vs triple, acoustic, solar control), colour (standard white is cheaper than custom colours), and how many panes open. It's also worth checking whether your installer's quote includes disposal of old frames, lintel inspection, and any making-good work around the reveals.

Get Advice on Aluminium Windows from National Plastics

If you're considering aluminium windows for your home, whether that's a straightforward replacement or something more involved, the team at National Plastics are on hand to help you navigate the options.

Every home is different, and the right specification depends on things like your property's style, orientation, and how you use the space. We can talk you through frame styles, colour choices, glazing options and what to look for when comparing quotes, so you can make a decision you feel confident about.

Browse our aluminium window range online or visit your local branch to see the options in person and get expert advice tailored to your project. Alternatively, you can send an enquiry online for personalised guidance from our expert team.

*Prices are a guide only and subject to change based on property, product choices, and installation requirements.

FAQs

Do aluminium windows rust?

No, aluminium can’t rust. Rust is a form of corrosion that only affects iron-based metals like steel. Aluminium doesn't contain iron, so it's completely immune to rust. It does form a natural oxide layer when exposed to air, but this actually protects the material rather than degrading it.

Will aluminium windows corrode over time?

Aluminium is highly resistant to corrosion, especially when finished with a powder coating. In typical UK residential environments, well-maintained aluminium windows should show no meaningful signs of corrosion or degradation for decades. Even in more demanding environments (for example coastal areas or high humidity regions), aluminium performs better than most alternative materials.

How long do aluminium windows last?

With proper installation and basic maintenance like routine cleaning and sweeping away debris, aluminium windows often last 40 years or more. The combination of the material's natural durability and a quality powder-coated finish means they can hold their performance and appearance for a very long time without major intervention.

Are aluminium windows hard to maintain?

Not at all, and actually they're one of the lower-maintenance window options available. A good clean with mild soapy water two or three times a year, an annual check of seals and moving parts, and occasional lubrication of hinges and locks is all that's usually needed.

Are aluminium windows better than uPVC?

Both are good options, and the right choice depends on your priorities. Aluminium tends to offer slimmer frame profiles (more glass, less frame), greater rigidity, a wider colour range and a longer lifespan. uPVC is generally more affordable upfront and is also very low maintenance. If you're comparing the two for your project, it's worth talking to the National Plastics team in your local branch: we can help you weigh up the options for your specific situation.