With over 12 years experience supplying and installing composite decking and cladding, our team can help you select the correct product for your project, while avoiding the pitfalls of some composite products that are destined to fail.
At DeckSmart we only sell products that we have been installing ourselves for several years. This gives our customers the confidence that the decking we supply will not fail. Now you may be thinking ‘fail’?, ‘what can go wrong with composite decking’?, well composite decking is a relatively new product which came onto the UK market back in 2010 with only a handful of companies manufacturing worldwide. Unfortunately a high proportion of these companies released their composite products without testing them in countries with climates that ranged from minus 10 degrees Celsius to plus 40 degrees Celsius, as is the UK’s range.
It soon became apparent that the products could not withstand our climate range and rainfall levels, with some products literally crumbling due to their lack of high density polymers.
Unfortunately, these products are still flooding the market today and this guide will hopefully help you identify them.
If it’s cheap, it’s cheap for one or more of the reasons below.
The Ratio: Composite decking is a blend of wood and PVC fibres, the higher the ratio of wood to PVC, the more absorbent the decking will be. Resulting in the decking swelling and eventually splitting, sometimes within the first year of installation. As wood is far cheaper than PVC, you will find plenty of cheap decking on the market with high wood to PVC ratios.
50% Wood – 45% PVC – 5% stabilisers & pigment is best
The wood: It is important that composite is made from hardwood fibres as these absorb less water than softwoods. This will result in a stronger board which is less prone to Algae and Mould growth.
A high percentage of composite decking is manufactured in China, their usual wood of choice is Bamboo which is nowhere near stable enough to produce a long lasting composite decking board, regardless of the wood to PVC ratio.
“Hardwood is Best”
The PVC: The most important factor to consider with the PVC element of the ratio is it’s UV stability, this is for two reasons. Firstly structural, as time in the sun’s UV rays will break down the polymers of cheap UV-unstable PVC resulting in the composite literally crumbling into dust.
Secondly, UV-unstable PVC will change colour, generally fading many shades lighter than the colour you original chose.
Again, UV-stable PVC is more expensive than unstable.
“HDPE is Best”
The Core Shape: 90% of cheap composite boards have a hollow rectangular core, this is to minimise the amount of material they have to use to produce a cheaper product. Unfortunately this combined with the other factors mentioned above can result in a composite decking board ‘unfit for purpose’
Hollow Circular boards can reduce material content too, however due to their arch like strength, this allows for even distribution of weight and also minimises the amount of expansion in the heat.
Solid boards are generally the strongest and are mainly used at commercial properties where there is a high amount of foot traffic. Solid boards are dearer due to the amount of material in them, they can however expand significantly.
“Circular Hollow is Best”
WPC (Wood/Plastic Composite): This is the most common type of composite decking on the market, it’s made from a blend of wood and PVC. The material on the surface of the decking is the same as the core. (usually rectangular hollow)
Capped (co-extruded): This is manufactured to a higher standard than WPC, the core is made from a blend of wood and PVC but the process also involves the top of the board having a hard wearing, UV stable PVC laminate capping. This results in a much better finish and colour that should last far longer than cheaper WPC variants.
This also means the boards are not porous at all, therefore moisture cannot access the wood/pvc core and cause the inherent problems with WPC.
