Discussion on the selection of materials for outdoor composite joists for decking: comparison and applicability analysis of steel, aluminum, wood, and plastic wood
As people pursue a higher quality of life, the beauty and practicality of outdoor space are increasingly valued. In the selection of materials for outdoor flooring, the keel is an important component of the load-bearing and supporting structure. The choice of its material is directly related to the stability, durability, and overall aesthetics of the flooring. This article will conduct a detailed analysis and comparison of the four common materials for outdoor composite joists for decking – steel, aluminum, wood, and plastic wood – to help readers find the right durable material.
I. Steel keel
1. Advantages
(1) Strong load-bearing capacity: Steel has high strength and toughness, can withstand greater pressure, and is suitable for outdoor floors with high load-bearing requirements.

(2) Corrosion resistance: Steel that has been treated with anti-corrosion treatment can be used for a long time in harsh outdoor environments and is not easy to rust.
(3) Good stability: Steel keels have strong resistance to weathering and aging, ensuring the stability of the flooring.
2. Disadvantages
(1) Heavy weight: Steel keels are relatively heavy, making them difficult to install and carry.
(2) High cost: Compared with other materials, steel is more expensive, which may increase the overall budget.
II. Aluminum keels
1. Advantages

(1) Lightweight: Aluminum has a low density and is light, making it easier to install and carry.
(2) Corrosion resistance: Aluminum has a dense oxide film on its surface, which has good corrosion resistance.
(3) Beautiful: Aluminum has a smooth surface and beautiful color, which can enhance the overall visual effect of outdoor flooring.
2. Disadvantages
(1) Relatively weak load-bearing capacity: Compared with steel, aluminum’s load-bearing capacity is slightly insufficient.
(2) High price: Aluminum is slightly more expensive than wood and plastic wood.
III. Wooden keels

1. Advantages
(1) Natural and environmentally friendly: Wood comes from nature and has good environmental performance.
(2) Tough texture: High-quality wood has high strength and toughness and good load-bearing capacity.
(3) Beautiful and natural wood has beautiful texture, giving people a warm and comfortable feeling.
2. Disadvantages
(1) Poor corrosion resistance: Wood is easily affected by moisture and rot, especially in harsh outdoor environments.
(2) Poor stability: Wood is easily affected by factors such as temperature and humidity, leading to problems such as deformation and cracking.
IV. Plastic wood keel
1. Advantages
(1) Environmental protection: Plastic wood composite materials are made of a mixture of wood powder and plastic and have good environmental protection performance.

(2) Corrosion resistance: Plastic wood materials have strong corrosion resistance and are suitable for outdoor environments.
(3) Good stability: Plastic wood materials have good anti-aging and anti-weathering properties, ensuring the stability of the floor.
2. Disadvantages
(1) Relatively weak load-bearing capacity: Compared with steel and aluminum, the load-bearing capacity of plastic wood is slightly insufficient.
(2) Higher price: The price of wood-plastic composite materials is slightly higher than that of wood and aluminum.
In summary, when choosing outdoor composite joists for decking, you should base your decision on actual needs, budget and environmental conditions. Steel joists and aluminum joists have higher load-bearing capacity and stability, and are suitable for occasions with higher load-bearing requirements; wooden joists and plastic-plastic joists have advantages in terms of aesthetics and environmental protection, but their load-bearing capacity and stability are relatively weak. The appropriate and durable joist material should be selected based on actual conditions.
