The South African climate provides the ideal conditions for homeowners to increase the enjoyment of their homes by adding decking that will greatly enhance the outside entertainment area of the premises, and provide style and appeal and a seamless transition as the living area is expanded into the outdoors.
It also considerably increases the asset value of the property.
The most common types of decking are wood, composite or plastic decking, and in this article we provide the pros and cons of these types.
As a natural product, a timber deck creates a comfortable, attractive and flexible feature that can be added to the exterior of any home at any level, whether raised or used as a direct transition from the interior. It can also be used to great effect around swimming pools.
Because timber is so versatile to work with, practically any shape, size, colour or style of deck is possible, and a wide variety of local and imported hard and softwoods is available to enable homeowners to find a decking option that will suit their needs.
With the new advances in sealing products, maintenance is kept simple and cost-effective. The old varnish-type sealants are no longer used, thus peeling and flaking of deck sealants is a thing of the past and less sanding is required – the total surface coat does not have to be removed if it hasn’t been neglected – depending on the timber species, but unless the wood has been treated in this manner it will be difficult and costly to maintain and will have a much-reduced service life.
Wood is the most commonly used decking material and there are many alternatives available. These include weather-resistant woods; pressure-treated wood (treated lumber that contains wood and preservatives); and hardwoods.
However, if you are using an imported hardwood, ensure that it has been certified by the Forest Stewardship Council (FSC). This is your assurance that the wood was grown and harvested in a legal, sustainable manner – and not illegally clear-cut from a rainforest.
A proper deck frame is the heart of the deck. Without a professionally installed frame, the deck won’t last regardless of what decking material is used. A reputable decking supplier should use only CCA-treated timber according to SABS standards, and should ensure that all end-cuts are treated. Pine that has been pressure-treated is the preferred wood in South Africa for deck frames, and this treatment dispenses with the need for end-cut sealants.
All metal fasteners and brackets to be used should be galvanised and non-abrasive, and all poles must be cemented into the ground and allowance made for proper drainage – particularly in the case of decks fitted on flat surfaces, where a space must be allowed under the timber frame for water drainage.
A typically ideal supporting structure should consist of gum poles with a diameter of 125mm set in concrete to a depth of 600mm, or 150mm in diameter set in concrete to a depth of one metre, depending on the height of the deck. This conforms to the engineering specifications to ensure maximum safety. All material used should be to SABS specification, and all structural timbers treated against rot and insect damage.
There are numerous timber species suitable for wooden decks, although it is recognised that timber that is sourced closest to home often offers the best value for money and is more readily available. For your guidance, a table has been inserted into this article giving the most popular hardwood species for wooden decking in South Africa.
Composite and plastic decking material
As an alternative to wood, you can consider the composite decking alternatives. Amongst the more recent additions to the decking scene are wood/plastic composite and plastic decking materials, so it is worthwhile examining the differences between them to enable firm decisions to be made.
Composite decking is a hybrid product that’s composed primarily of wood fibres and recycled plastic. The result is a dense, heavy, and weather- and stain-resistant deck board that won’t splinter, warp, rot or split.
The appeal of composite decking is that it’s virtually maintenance-free. It never needs to be sanded, scraped, refinished or stained. An occasional scrubbing with warm, soapy water will remove most dirt and grime, but you should consult your supplier for the correct cleaning and maintenance programmes. Most suppliers should stock soaps and UV sprays to maintain the specified product.
Some standard composite decking comes in limited colours – brown, grey, tan – and most will fade over time, especially where the deck is exposed to direct sunlight. However, most manufacturers now offer a line of fade-resistant composites which cost a bit more but retain their colour much longer. Most products also have realistic-looking wood-grain patterns moulded into their surfaces.
Composite decking is eco-friendly, because the wood plastic decking is made from 95% recycled material, contains no toxic chemicals or preservatives, and is certified green for sustainability as well as energy and water efficiency.
Regarding strength, composite decks are durable, saving time and money on a decking solution that lasts longer with no risk of warping or cupping. They also have proven stain, scratch, mould and fade resistance in our climate, and are easy to install.
In addition, due to the encapsulation process used in production, composite products are less susceptible to the buildup of moisture – making them ideal for coastal conditions.
Low-maintenance decks made from composite materials don’t need to be re-painted, re-oiled or re-stained, requiring only a quick sweep or wash every so often and, finally, do not splinter and are non-slip, making such a deck completely barefoot-friendly and thus the perfect surface for areas around the swimming pool.
Wood-plastic composite mostly uses polyethylene plastic, which comes from recycled plastic products with additives aiding the manufacturing process and improving suitability for construction. However, some may contain polyethylene or resins, so take the advice of your supplier on which to use.
PVC decking is made from 100% plastic (recycled and/or virgin) and contains no wood fibres or fillers. It can be shaped to achieve almost any structure, requires no finishing and will never splinter. It can be easily washed and maintained, and also resists rot and mould, together with stains from a number of substances, and comes in a wide range of colours.
The downside of plastic decking compared with the other options is that it’s designed as part of an overall system, therefore it must be installed with strict adherence to manufacturer’s instructions. This often requires purchasing special fasteners, fascia boards and trim pieces.
As can be seen from the foregoing, any decking requirement – residential or commercial – can be met with a variety of different options, but the South African flooring industry can meet any requirement with the solutions, expertise and workmanship standards that ensure a perfect installation and an asset that will last for years.
The following hardwood species are the most popular for wooden decks in South Africa
Also known as Zambezi redwood, umgusi and mukushi, it grows in Zambia and Zimbabwe. Rhodesian Teak has a fine, even texture, often with black flecks and much paler sapwood, and it has a high resistance to abrasion and decay.
Saligna is a variety of eucalyptus that originates in Australia; in South Africa eucalyptus has been declared an unwanted species because of its water consumption, but there are commercial plantations in the eastern part of South Africa which should provide enough timber for quite a few years to come. Of all hardwoods used in South African decks, saligna is the most readily available.
Red Iron Bark
Originates in Australia. It is one of the densest timber types and has an outdoor lifespan of approximately 30 years. It has a reddish-brown finish, is very stable and perfect for African climates.
Originates in northern South America, Brazil and the Caribbean. Natural latex is made from its sap, which makes it a very durable timber. It has a rich deep-brown finish and is a very dense timber.
Originates in Brazil. It has a natural resistance to rot, decay and insect attack. Garapa has a golden to light-yellow finish, and is a stable hardwood that fits in comfortably with the natural environment.
Is mostly imported from the Philippines. It is a durable timber that has been used in South Africa for a number of years. Its colour varies from light brown to a reddish purple, and it is very popular due to its availability in long lengths, thick planks – perfect for structural use.