Composite decking seems like a great idea on paper, and there are actually many advantages to choosing composite decking for your outdoor space.
However, if you’re looking for a type of decking you can simply screw into place, composite decking may not be the right choice for you.
Read on to find out why screwing composite decking isn’t the best idea, and what you can do instead to ensure the longevity and strength of your deck moving forward.
Why Shouldn’t You Screw Composite Decking?
Screwing composite boards into place might seem like the easiest option when the time comes to install the decking, but this could cause some problems later on.
Far from being easier, the issues screwing your composite decking can cause will cost you time and money in the future, so it’s best to put more effort in at the start to avoid extra maintenance later.
Composite decking in many ways can be treated the same way as wood decking. Except for screwing the decking down.
However, the difference between timber and composite is that the former move as much as wood. Composite will regularly expand and contract as the temperature fluctuates.
Therefore, putting deck screws into composite material creates pressure because the expansions and contractions are restricted.
The pressure is centred around the holes made by the screws, and over time, warping and cracking tend to occur.
Standard deck screws will also cause mushrooming of composite material around the screw head. Making the smooth face of the decking rough and frankly, ugly.
There are better ways to install composite decking.
How To Install Composite Decking Instead
So, if it’s not a good idea to simply screw composite decking into place, what should you do instead?
To start with, although using regular screws to hold your composite boards in place is not recommended, you could use hardware known as composite screws.
Basically, composite screws (also known as composite deck screws) are designed to grip the material more tightly compared to screws designed for regular timber.
Another difference between normal screws and composite screws is that composite screws have smaller heads.
This is so that they countersink deeper into the material and look cleaner overall.
Because composite screws sink deeper into the material and grip more tightly, these screws will be more resistant to the pressure caused by the composite expanding and contracting.
That means you might be able to keep your composite decking looking good for longer while still going the traditional route by screwing the boards in place.
However, even holes made by composite screws are likely to eventually succumb to the pressure.
That’s why we have another method of securing composite decking that we think will work better in most cases.
Clips For Composite Decking
As more and more people started installing composite decking and realized that screwing the boards into place led to short-lasting results, manufacturers started developing alternative installation methods.
While not all composite decking is grooved, the kind that has grooved edges can be used with clips or fasteners.
These clips are designed to fit in between the boards in your decking, so the first advantage compared to screws (even composite screws) is that they can’t be seen easily.
You affix composite decking clips to the joists of your grooved composite boards, leaving a gap to allow air to circulate between each plank.
This extra ventilation should help to prevent rotting and mould should the composite material be exposed to moisture.
Once you’ve put the clips in place, you use a drill to place a screw into the hole in the clip rather than through the composite material itself.
You will still need to put one screw through the final board in your decking (the one on the outer edge of the deck) because you won’t be able to clip the outer side of this board into place.
However, if you use a composite screw for this task, the pressure shouldn’t be excessive, and if you drill a pilot hole rather than trying to put the screw into the material straight away, you’ll be able to create some breathing space and diminish pressure around where the screw will go.
Composite Face Screwing Alternative
Another option is to edge screw the composite decking.
Fastening the decking down to the joist with a screw installed on the edge of the decking. Keeping the face of the decking unmarred by screw heads but without the additional cost of plugs or clips. The most popular edge screw system is Camo. Which makes edge screws for both wood and composite decking.
Both Azek and Wolf will still warranty their decking when edge screwed. But it must be done properly with approved fasteners. For Azek that is SIDELoc™ Hidden Fastener, similar to Camo Edge.
Before edge screwing your decking always check that the brand warranty allows for edge screwing.
Hate to save a few hundred dollars on fasteners only to void a few thousand dollars in decking warranty.
Frequently Asked Questions
Can You Drill Composite Decking?
Yes, you can use a drill to create pilot holes in composite decking.
This will be necessary even if you’re primarily using clips to hold your decking in place because the outermost board will need a single screw to hold it in place.
In fact, it’s even more important to use a drill to make pilot holes in your composite than it would be for tinder.
That’s because composite material expands and contracts more than wood, so if you don’t drill a pilot hole, there will be no room for the material to breathe around the screw and you could end up with cracking or warping.
However, you should make sure to use the correct drill bit and not turn the settings up too high on your drill since you want to avoid accidentally splitting or cracking the material, which can happen with composite boards as well as tinder.
Where Do Screws Go In Composite Decking?
If you are using composite screws to install your composite decking, or even if you’re just putting in one screw to hold the final board in a clip installation, you need to know the proper placement for the screws.
Most composite decking requires that the screws be installed a minimum of 3/4″ (188mm) from the edge of the decking. Ensuring there is sufficient material so as not to split the decking with the screw. Here to drilling, a pilot hole is best to prevent damage.
Ideally, you use composite deck clips for the field boards to minimize the appearance of screws and only have screws installed on the edge boards and along the house where you cannot use clips.
Do You Need Special Screws For Composite Decking?
Some people still choose to use regular wood screws to install composite decking, but because of the expansions and contractions that happen with composite material, regular screws are not an effective way of holding the boards in place.
We recommend using clips if you can, but if your decking doesn’t have grooved edges, you should use special composite screws that grip the material more tightly and also go deeper into the material for a longer-lasting, less visible hold.
Since the heads of these screws are also smaller, the pressure exerted on the composite when it expands should also be reduced.
Can you Hide Face Screws On Composite Decking?
With many composite decking brands, you can use composite plugs to hide the screw head after installation.
FastenMaster makes Cortex plugs for Azek, Timbertech, Trex and Wolf from matching capstock material that can be installed to camouflage the screw head.
StarBorn pro plug is a similar product for Azek, Deckorotors, Fiberon and Trex to name a few brands.
Simpson Strong Ties also make plugs for a variety of brands, including Trex.
These can only be used on solid composite decking. Where there is enough material for the screw to be counter-sunk but still hold the decking. The exception is Fiberon. Fiberon’s Goodlife boards have enough material for the screws to be counter-sunk but still, hold even with the scallop bottoms.
Composite decking is a decking material that will benefit you in a number of ways – but only if you know how to install it properly.
If you don’t have grooved decking boards, you may need to screw them into place, but you should use composite screws to avoid warping and cracking due to the pressure caused by regular screws when the material breathes.
Where possible, we recommend using clips or fasteners between the composite boards to hold the decking in a way that doesn’t cause so much pressure.
Before you put the last screw into the outermost board, make sure to drill a pilot hole to make breathing space.