Dealing with Composite Decking
While composites and plastics have their benefits, comfort on a hot day is not one of them. The plastic layer surrounding the composite holds heat. Some surfaces that are exposed to direct sunlight all day may be too warm to walk on bare feet. This will depend partly on the colour of the material. Lighter coloured decking will tend to reflect more of the heat, where darker colours will absorb the heat and tend to get hotter faster reaching high temperatures.
Like most wood or composite decking there needs to be some space for expansion and contraction. The other issue is the deterioration of the wood joists under the composite decking. This is due to the drying qualities of composite decking. Wood decking will absorb moisture and release to the air around it. Composite decking does not absorb water. Moisture that gets trapped under the decking and on top of the wood joists tends to stay there and keep the joist from drying properly. Wood that is not allowed to dry properly will be more susceptible to rot and decay.
Composite decking is made of a combination of wood and plastic. This combination is intended to reduce the chance of rot and extend the life of the deck. The material is not indestructible. The surface of the boards can be scratched rather easily. Composite decking cannot be resurfaced. Apparently you can use a heat gun and a wire brush, but this is not recommended, as you are more likely to further damage the material and cause melted and uneven areas.
One of the most common complaints about composite decking is mould. Decking that is in shaded areas or areas that tend to get wet frequently have been shown to grow mould and stain the deck. This is not restricted to composite decking. Wood decking can grow mould, mildew and algae. For wood decking, the remedy for mould is cleaning and resurfacing. Composite decking requires using special cleaning chemicals that will kill the mould and remove some of the finish. This will leave the decking more porous and susceptible to more mould growth.
Many composite decking companies have beautiful brochures with images of elaborate decks of different colours and looks, but many of these companies will not show you the deck several years later when it is faded from contact with the sunlight. Wood decking can fade too, but you can re-stain wood. There are some products out that claim to restore the composite decking to near new conditions, however their efficacy is unknown.
No matter what material you choose for your deck, it's going to need maintenance — a minimum of one annual cleaning. Most composites and plastics need a regularly applied finish (once or twice a year) to keep from fading, but most decking wood can be left finished or unfinished. While wood is more susceptible to rot and warping, mould spots are more difficult to remove from composite and plastic decking. In contrast, a stone deck requires very little to no maintenance - it's as easy as hosing it off in the spring!