Aluminium and Composite Decking: Pros & Cons

When it comes to choosing what material to use for your decking, the options in the market are aluminium and composite. You can choose one based on your requirement of usage, height of building, style and of course, cost. Weather is another essential factor to consider since your deck will most likely be exposed to different types of weather conditions such as rain, exposure to the sun, and change in temperatures. We’ve put together a list of pros and cons of each type of decking, that you can use to decide what works best for you – once you’ve got past an important factor—the cost.

Short Term Cost vs Long Term Cost 

Between composite and aluminium, aluminium is the costlier option short term. However, do consider the amount of material you would need. As your quantity requirement goes up (per square feet), the price gap becomes smaller, making them almost equally affordable. Composite decking can have up to 50% wood or wooden fibres in it, making it susceptible to rain or moisture. In the long term, this would make aluminium decking a more affordable option.

Pros and Cons of each Material

Now that we’ve understood the costs of each material for decking, let’s go on to understand the benefits and disadvantages of each material. 

Aluminium Decking


  • Aluminium is three times stronger than composite decking.
  • It doesn’t need to be replaced as often making it more affordable long term. It has a lifetime of over 30 years. 
  • It is durable and non-combustible making it a great option, especially in balconies of high rise buildings. 
  • It is very light in weight, making it much easier to install. 
  • Natural interlocks prevent leakage of water.
  • Aluminium can be recycled infinitely without losing its quality, making it a highly sustainable option


  • It is an expensive option due to its short term costs. 
  • There are also fewer design options available in aluminium decking. 

MyDek aluminium decking products are certified to A2-s1,d0 in line with the amended Building Regulations

Composite Decking


  • Composite decking made from plastic is recycled and good for the environment.
  • It’s free of toxic chemicals and requires less deforestation for its production. 
  • Composite decking arrives as a finished product and doesn’t require high maintenance.
  • It can easily be cleaned with soap and water
  • The combination of wood and plastic is safe for children since it is splinter-free and slip-resistant. 
  • There is no maintenance cost and can last up to an average of 15 years. 
  • In terms of decor, these come pressed with a pattern or a wood grain, and you can choose what you’d like.


  • Considering that the wood fibres in this make it more vulnerable to rain and moisture, most manufacturers will only provide up to 10 years of warranty for Composite decking. 
  • Up to 10-15% of its colour can fade away due to the sun, and it’s not 100% free from mould and decay. 
  • Composite decking is often Fire Retardent which means it cannot be used in buildings that are above 18m, and used as sleeping places.

Specifying Decking

Under the new regulation, any and every building work which starts after 20th February 2019 must follow certain specifications. The goal of these is to ensure that no balconies or decks constructed in new buildings are made up of combustible materials. This applies to:

New buildings that, 

– are above 18m, and

– are used as sleeping places for people.  

The new regulation sets out that all the components of the walls, decks, balconies in building above 18m must be tested as non-combustible (European Classification A2-s1, d0 or A1). Non-combustible materials include concrete, metal, stone and ceramics. Materials are classed as non-combustible when they do not contain any material which could burn when exposed to fire.  Composite and wooden decking products are no longer feasible under the new regulations since they do not fall under the Euroclass system categories A2-s1,d0 rated or class A1. Email our team about Aluminium Decking on [email protected]