Decking Materials Compared

01

Hardwood timber

Hardwoods such as balau, meranti, teak and certain oak species are popular for decking because of their density and natural resistance to moisture and insects. These timbers tend to be heavier and more stable than softwoods, which reduces warping and cupping over time. Hardwood decking usually develops a silvery grey patina if left untreated and exposed to sunlight, or it can be kept closer to its original colour with regular oiling.

Advantages and trade offs

• Dense grain gives good resistance to scratching and general wear
• Naturally more resistant to rot and insects than many softwoods
• Heavier material requires a correspondingly sturdy substructure
• Sourcing responsibly harvested timber is worth confirming with a supplier

02

Treated softwood

Pine is the most widely used softwood for decking in South Africa, typically treated with preservatives to improve resistance to rot and insect attack. Treated pine is generally lighter and easier to work with than hardwood, and it readily accepts stains or paints, giving more flexibility over the final colour. Because it is softer, it is more prone to surface damage from furniture, pets or foot traffic over time, and the preservative treatment needs to remain intact for the wood to perform well.

03

Composite decking

Composite boards are manufactured from a blend of wood fibre and plastic, often incorporating recycled material. They are designed to resist rot, insect damage and splintering, and they do not require the periodic sealing or oiling that solid timber needs. Composite decking tends to hold its colour less consistently in strong, prolonged UV exposure compared with some claims made by manufacturers, so checking warranty terms and UV ratings for the specific product is worthwhile. It is also generally heavier underfoot than timber and can retain more surface heat in direct sun.

Where composite suits well

• Areas where low maintenance is a priority over natural wood appearance
• Pool surrounds, where water exposure is frequent
• Humid coastal regions where timber maintenance is more demanding

04

Metal and PVC systems

Aluminium and PVC decking systems are less common in South African residential settings but are sometimes used for commercial projects, rooftop applications, or situations needing very low maintenance and high durability. Aluminium decking is lightweight, resistant to corrosion when properly coated, and does not rot or attract insects, though it can be more expensive and has a distinct appearance compared with timber or composite.

05

Matching material to site conditions

The right material depends heavily on local conditions. Coastal properties exposed to salt spray often benefit from naturally durable hardwoods or composite boards with corrosion resistant fixings. Inland properties with strong sun exposure may prioritise UV stable finishes or composite products rated for high temperature climates. Gardens with heavy tree cover and persistent dampness may favour materials with strong rot resistance and good airflow in the substructure design.

06

A note on fixings and substructure

Whichever decking board is chosen, the screws, brackets and substructure timber or framing also need to be suited to the environment. Stainless steel or coated fixings are commonly recommended in coastal or high humidity areas to reduce the risk of rust staining the boards. The substructure itself should allow for adequate ventilation underneath the deck to help timber dry out after rain and reduce the risk of rot developing out of sight.

Material choice is only one part of a successful deck. The companion page on this site covering maintenance explains how to look after a deck once it has been built, regardless of which material was used.