By Ken Patrick
As building costs increase, so the trend towards smaller homes grows. In Cape Town Central, micro-apartments of just 19 square metres are currently being sold at close to R1-million. And so, the opportunity to expand one’s living space at a fraction of the cost is a logical option.
The fact that our climate and lifestyle make outdoor living so much more attractive and accessible makes the addition of decking to a building a no-brainer, whilst adding to the resale value of the property.
Traditional timber decks are still very popular, from SA pine through to a wide variety of hardwood options. Depending on the choice of wood, and the level of care and maintenance, a timber deck will likely last from 10 to 30 years and offers a natural look. More recently, the trend is towards WPC or Wood Polymer Composite decking, and as with timber decking, there are many choices in terms of suppliers, profiles, colours and quality.
WPC combines recycled wood chips with plastic (usually Polypropylene or Polyethylene). The wood (reduced to a ‘wood flour’) provides strength and is encased in the polymer which provides the weatherproof and wear benefits of the product. Profiles made from WPC originated in the US automotive industry, with the first patent lodged in 1985. Chances are that the moulded parcel shelf in your dad’s sedan was probably made of WPC.
By the early 90’s the technology had developed such that profiles could be extruded as a finished product and so the applications grew. Nowhere was this more successful than in outdoor decking and handrailing, which still represent the largest markets for this material.
Subsequent product development has been rapid, with manufacturers all over the globe now producing solid and hollow boards using single or multiple extrusion processes. The result is a plethora of choices in terms of structure, profile, size, colour, embossed finishes and jointing systems.
Basic products tend to be monochromatic (they offer a solid colour and consistent material throughout the profile). They also tend to be more basic in design, usually with straight ridges, or smooth surfaces. Contrary to expectations, these basic products are slightly porous, and as such they can stain if certain substances (particularly oil based) are left in contact with the surface.
More recently, the availability of co-extruded decking boards has increased, with an emphasis on what is known as capped decking or encapsulation. The idea is that a second layer of pure polymer is extruded over the decking board. Sometimes this is limited to the top surface but can cover the entire profile. The advantages of capped decking boards are multiple. Not only does this extra layer protect the boards from fading, moisture absorption and staining, it also provides extra wear resistance, and allows manufacturers to introduce life-like woodgrain patterns into the polymer layer, enhancing these with variegated colours.
Whereas the original products didn’t really try to look like wood, they just offered a harder-wearing lower-maintenance alternative, modern offerings feature extremely lifelike patterns, textures and colours.
Applications for the products have also developed beyond the original decking and handrailing uses. Fascia and corner profiles have become a standard part of the range, but more recently there has been an increase in the range and styles of cladding products available, and this offers a host of options when combined with alternative building technologies such as Timber Frame, Lightweight Steel Frame and SIPS. It is therefore possible to completely clad a structure in maintenance-free WPC cladding, including window and door reveals, internal and external corners.
Whilst there are many positives regarding WPC, customers should be aware that WPC is a compromise. Whilst is represents an effective, harder-wearing, and lower maintenance alternative to timber, it cannot be installed in the same manner as timber. WPC is not as strong as solid timber and therefore requires closer intervals for its supporting structure. Being part polymer, WPC expands and contracts with varying temperatures. This varies widely depending on the structure and quality of the boards, but an allowance of 1-2mm per linear metre is common. Whilst it is scratch resistant, WPC is not bulletproof so, whilst a dent in a timber deck might add character, the result on a WPC deck is not so flattering.
It comes down to a basic choice between traditional timber which will have a limited lifespan (especially if not maintained) vs a look-alike WPC alternative which will require less maintenance, offers a longer lifespan (guarantees range from 10 – 25 years), will not fade or rot, and features a range of colours to complement the rest of the building.
In the coastal area where I operate the market is still 50:50 with WPC more likely to be installed in higher-priced new buildings, and timber being favoured for extensions to existing homes. But both work, both can look amazing, and both offer a less costly option when looking to expand a building’s footprint.
About the author
Ken Patrick is the owner of Decks Etc. a decking supply and installation company. Having spent several years involved in plastic pipe extrusion in Gauteng, Ken accidentally started the business 15 years ago when he moved to the Southern Cape and came across early versions of WPC decking being marketed in South Africa. The business has grown steadily, using of both timber and WPC materials with successful projects completed all along The Garden Route, including Pezula, Fancourt, Oubaai & Pinnacle Point.
“Whilst there are many positives regarding WPC, customers should be aware that WPC is a compromise.”