Aluminium and steel are both popular materials for sliding patio door frames, but what are their key differences and which is better? Aluminium is a lightweight and durable metal that is resistant to weather exposure. Steel is an extra strong, tough metal that is susceptible to corrosion. However, there are even more pros and cons to weigh up when deciding between the two materials.
In this comparison guide, we outline the advantages and disadvantages of steel and aluminium sliding doors to help you choose the right material for your patio door.
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Read our guide to the colour choices, frame widths and styles of steel and aluminium sliding doors.
Read a comparison of the strength, operation and corrosion risk of aluminium and steel sliding doors.
We answer common queries on choosing between aluminium sliding doors and steel doors.
Aesthetics
Colour choice
Aluminium and steel sliding doors offer a fairly similar aesthetic. The metal frames are powder coated and a variety of colour finishes are available. However, aluminium doors tend to have much more variety than steel.
Here at Origin, our aluminium sliding doors are available with more than 150 RAL powder-coated finishing colours. Some of the finishes even mimic the appearance of natural wood to offer a traditional aesthetic. With steel, the finishing options are much more limited because paint often has a difficult time adhering to steel, and only weather-resistant paint should be used to protect the steel from corrosion.
Frame width
Another difference between aluminium and steel is the frame width and sightline that they can offer. Steel can often be manufactured with slimmer sightlines than aluminium. However, it does tend to be a heavier material, so the doors can get quite heavy. Despite this, well-engineered aluminium doors can offer slim frame widths and give steel doors a run for their money.
Aluminium is a sturdy enough material to support very large panes of glass, but it's also very versatile in terms of how manufacturers can work with it. As a result, it is possible to create an aluminium sliding door with sightlines as slim as 20mm in the case of our Original Artisan Slider OS-20.
The slimmer the sightlines, the less interrupted the view from your patio door will be. Steel is even stronger than aluminium, but its versatility is limited when it comes to manufacturing methods and it is difficult to achieve large panels with very narrow frames.
If your patio door is set to highlight a beautiful view, it might be better to opt for aluminium to maximise this focal point.
Style
When choosing between an aluminium and steel sliding door, consider the style and décor of the property. Robust steel frames can provide a very industrialised look, which is ideal for modern new builds and urban properties, but it tends to look out of place in many traditional homes or in historic, listed properties. Aluminium patio doors also have a contemporary look, but they're a little sleeker and more elegant than steel and can give a modern edge to a traditional property. Our sliding door systems also offer a variety of sightline options, so you can choose the width that’s right for you.
You can see our full range of aluminium sliding patio doors here.
Practicalities
Strength and security
Steel is an incredibly tough and strong material, much more so than aluminium, and it therefore offers greater security benefits because it is almost impossible to bend. However, aluminium is not by any means a weak material and offers excellent resistance against forced entry, especially with the locking systems available.
Ultimately, both materials offer plenty of security for most properties, and it is the locking mechanisms and cylinder options of the door that are most important when it comes to keeping out intruders. Steel and aluminium doors are on a par when it comes to the locking mechanisms available for them.
Risk of corrosion
One of the biggest disadvantages of steel is its propensity for corrosion. It can discolour, rust, and gradually break down when exposed to water. Although steel patio door frames are usually finished with a protective coating, this has a tendency to break down over time and the frames must be very carefully maintained to keep them in good condition.
Sometimes galvanised steel is used to inhibit corrosion, but this is difficult to paint and colour options for galvanised steel door frames are very limited. Corrosion of steel door frames occurs faster in coastal areas, so consider the geographical location of your property before opting for steel. Meanwhile, powder coated aluminium is sealed, so is more resistant to corrosion and very little maintenance is required to keep it in good condition. An aluminium sliding door can last for decades without deteriorating in appearance or function.
Ease of operation
An important benefit of aluminium is that it is incredibly light, which means they are easy to open and close. Steel, on the other hand, is very dense and heavy, and the operation of large steel doors can be difficult.
Consider the size of opening for your patio doors. If it is set to be very large and you would like big door panels to minimise interruptions in the view, aluminium is a better option than steel.
Cost
Cost is a vital factor to consider when choosing between steel and aluminium sliding doors. Aluminium is a reasonably affordable material, whereas good quality steel that is manufactured to resist corrosion tends to be much more expensive.
Cheap steel doors are unlikely to offer a good lifespan because they're more susceptible to corrosion. Good quality, premium aluminium sliding door frames make for a sound investment because they can last for decades.
Frequently asked questions
Which are better, aluminium or steel doors?
Aluminium doors tend to be more affordable than steel. They're also lightweight and easier to operate, and they do not corrode when exposed to the elements. Steel is stronger than aluminium, but it can rust and corrode which might affect the lifespan and reliability of the door.
Do steel doors corrode?
Steel is susceptible to corrosion, but the rate of corrosion depends on the type of steel used. Galvanised steel is resistant to rust, but it is tough difficult to paint or customise, which makes it an unappealing material to use for doors where most people want a colour of their choosing. Stainless steel can be painted, but this is susceptible to corrosion unless finished with a weather-resistant paint.
