Advantages and Disadvantages of Composite Wood Decking

Composite wood has increasingly become a popular alternative as an alternative to natural wood decking , widely promoted as a low maintenance product that will not twist, warp, splinter or fade like natural wood produts used outdors . And indeed composite wood does exhibit some excellent characteristics, but there are other aspects to composite wood which it is useful to be aware of .  Let's look at these in turn .

Firstly, it should be noted that like most products, composite wood will vary between different manufacturers since not only can the basic components vary : polyethylene or polypropylene, new or recycled plastic materials or any ratio of the two, wood fibre, bamboo fibre or other fibre components or a mixture of these plus reclaimed wood material , but minor components such as UV stabilizers, processing aids etc will also vary. And any of these components together with the actual processing and extrusion procedures can affect the final properties and characteristics of composite wood decking. So the comments below must only be taken in a general context .

1. No twisting or warping. Providing that the composite wood profile has been extruded carefully so that no stresses have been allowed to build up in the profile, then it should be expected that composite wood decking should not twist or warp under normal conditions. However in some situations has been reported that composite decking can exhibit some bowing along its length, although this will not necessarily be a problem if the decking is firmly screwed or nailed to bearers. It may however cause some slight problems with interlockingcomposite wood deck tiles where the slats on the tiles are not firmly attached to bearers underneath and where bowing could contribute to potential tripping hazard .

2. Fade resistant . Providing the manufacture of the composite wood decking has used good quality colour pigments resistant to fading in sunlight , then indeed composite wood decking will normally exhibit very little fading .  Typically the colour will fade only about 10% in the first three to six months but will then fade very little after this time .

3.  No splinters .  Composite wood decking should not splinter since it does not contain long sharp fibres.

4. Staining . Composite wood is not resistant to staining, and it is a good idea if the material is to be used around outdoor grills etc, that a sealing product designed specifically for composite wood is aapplied as soon as possible after the deck installation .

5. Structural strength. Generally speaking , composite wood will not have the structural strength equivalent to the strongest hardwoods such as eucalypus hardwoods or Ipe . It also needs to be supported by bearers at closer intervals than natural wood decking, since it is prone to sagging. With composite wood deck tileshowever which are laid on firm surface, this will not be an issue.

6. Mold and mildew resistance. Whilst composite wood may contain some additives to reduce the formation of mold and mildew, most reports indicate that composite wood does not show any increased resistance to mold and mildew compared with natural wood.

7. Decay & Rot Resistance. Composite wood used in exterior locations should not decay or rot under normal conditions , although there have been some cases apparantly where as result of faulty manufacturing of defective components where composite wood has shown unacceptable deterioration in use.

8. Insect resistance. Since composite wood decking is partly composed of a plastic material it will not normally be subject  to attack by wood boring insects.

9. Resistance to scratching and marking. Composite wood is not a particularly hard product , so will not have the same resistance to sscuffing and marking as the hardest natural woods such as Ipe.

10. Fire resitance. Since composite wood is composed of a plastic material and wood fibres, it is not fire resistant , whereas some hardwoods such as Ipe have a class A fire rating .

So like most materials, there are pros and cons of using either natural wood or composite wood, so it's really up to the individual consumer to decide which characteristics are important to them when selecting materials for a new deck .