Think twice about screwing composite decking.
If you screw composite decking down this may seem an obvious simple alternative to using clips but using this fixing method can damage the boards and void the warranty. Whether you’re a landscaper, “30 years man and boy” and you know your way around a tool shed, an accomplished DIYer or a novice handyman there are things you need to know about installing composite decking. We’re not trying to teach you to suck eggs, we just want to give you a couple of useful pointers about the differences between composite decking and timber and why you shouldn’t screw composite decking.
After all, if a job’s worth doing, it’s worth doing right, right?! So, can you screw composite decking down? Strictly speaking, yes you can, but you shouldn’t. As well as voiding your composite decking warranty, screwing boards in place will cause you all kinds of problems in the long run, which you will need to return to and rectify, so it’s best to get it right first time.
Why Shouldn’t You Screw Down Composite Decking?
Despite the many similarities between timber and composite decking, one major difference is the way in which you can fix it in place. Timber expands and contracts (breathes) very little, in comparison to composite wood and can be easily attached using screws. Once fixed, screw holes will expand and contract by a negligible amount.
Composite decking is a combination of wood fibres and plastic to protect the timber against moisture. The plastic element ‘breathes’ to a much greater degree and so must be fixed in a manner which is suited to the composite material. Composite materials behave differently to wood in changing temperatures. Fixing the composite deck boards with a screw is almost pinning the product to the joist and therefore inhibiting a natural level of expansion and contraction. Over time, this constant pressure around the screw holes will cause the composite decking to crack and potentially warp over time.
Purpose-Built FastClips Allow For Expansion, Contraction & Drainage
To allow the composite material in our decking boards to expand and contract naturally, we have engineered specially designed FastClips to fix the boards down. Fixing directly to the joists, rather than through the boards, the FastClips have the profile of a ‘winged V’. The tips of the ‘V’ sit snugly within a deep groove which runs along the edges of the decking boards. Starter Clips can be used on the first run which are on just half of the ‘V’ to give a clean edge.
Supplied in packs of 3mm stainless steel clips or 6mm plastic clips, these FastClips are designed to enable easy installation and a breathing gap between each board for ventilation and drainage. The 3mm clip gives a very neat finish with a minimal gap between each board. The 6mm clip has a larger gap but can be more easily maintained.
If you were repairing decking or replacing a board in the centre of your deck, how you go about it would depend upon which clip was used for installing decking in your garden. A 6mm clip has a gap wide enough that a drill can positioned between to remove just one or two boards easily. The 3mm clip has concealed screws and so any repair could only be undertaken once sufficient boards had been removed from the final edge to the middle, as boards are interlocking.
For a secure fix, the final board will need to be screwed down on its outer edge as this is the only way to attach the top edge. As stated above, a pilot hole will need to be drilled for this one-off screw fixing as this will allow the board to ‘breathe’ around the screw. Drilling of holes should be done using a timber tungsten-carbide drill bit.
Need Further Support or Advice?
If you’ve still got questions that have not been answered here, or you would like additional advice,
support or assistance then please give one of our friendly experts a call and we’ll be happy to help.
Just give us a call on 01530 382 180.