Hidden clips vs face screws for composite decking

The board you buy has already made most of this decision for you. A grooved-edge composite board is designed around its maker's hidden clip, and the install guide will tell you to use that clip across the field of the deck. Face screws go where a clip cannot reach, which usually means the first and last boards, the fascias and borders, and the stair treads. A square-edge board is face screwed. You still get to choose the clip system where the maker allows more than one, and you get to decide now whether you want to lift a board out again in five years.

How do you fasten composite decking?

A hidden clip is a small nylon or metal fitting that sits in the groove milled along the edge of the board. You drop it in and drive one screw through it into the joist. The next board then pushes on so the clip's other side sits in that board's groove. The clip holds both edges down and sets the gap between them. One maker's clips come in two gap sizes, 3 mm and 6 mm¹, and another maker offers 3 mm and 5.5 mm⁵. In both systems the clip you buy sets the gap. Some systems add a locking clip, one per board placed nearest its centre, to stop the board shifting along the joists and out of line.

Face screwing is two screws down through the top of the board at every joist². With most composite you pre-drill and countersink every hole, keep the screw well in from the end and the edge, and drive it at low to medium torque until it finishes flush. One guide warns that some screws make the cap layer mushroom around the head, and asks you to test the screw on an offcut first⁵. Check the minimum distances in your guide. One maker puts them at 15 mm from the end and 20 mm from the edge², another at 38 mm from both⁵. One maker supplies its own screw and driver bit and says there is no need to pre-drill or countersink⁶.

Why the groove matters

Clips only work on grooved boards, and a grooved board ripped along its length loses its groove on one side. That has two consequences worth planning for before you order.

The first is at the house wall. The last board usually needs ripping to width, and the guides have you face screw it. One manual also has you rip the groove off a board on purpose to make a square-edged board for the outside edge.

The second is the edges and stairs. In one guide, picture-frame boards and fascias are face screwed, and the stair treads take face screws as well as clips⁵. Another clips its border boards into noggings and fixes their outside edge with brackets or screws¹. Count the face-fixed boards when you order, because a clipped deck still needs a box of screws.

Which clip, and will the maker allow it

Makers are specific about this, and it is a warranty matter. One maker's concealed-fixing sheet specifies a preferred clip and allows a biscuit-slot system as a slower alternative. The same sheet bans fixings that cut well into the side of the board and lists the products it means³. Using any other concealed system needs written permission from that maker first. Another maker says face fixing the whole deck is not recommended, and if you must do it, to pre-drill slightly oversized holes and test the screw on an offcut⁵.

The clip also has to suit the frame. One guide lists separate timber-fix and metal-fix versions of its clips. The guide rates its metal-fix screws for steel up to 2 mm thick, and thicker steel needs every hole pre-drilled⁵. One maker's steel-fixing sheet says steel frames move a good deal with heat and with stresses built into the steel. It adds that its preferred clip system helps in "de-stressing" the deck⁴. I read that as the clip letting the board move a fraction where a screw would pin it. A clip maker whose clips suit two of the composite brands sold here says its nylon clips fix to timber or steel joists with screws, connector nails or a nail gun⁹. The frame side of that choice is in steel vs timber deck frames.

Near a pool or the sea, the clip material matters. One guide says only its nylon clip models or stainless steel clips may be used around pools and within a kilometre of salt water². The clip maker rates those nylon clips for coastal areas and for salt or chlorinated pools⁹. A Whirlpool member in far north Queensland wrote in November 2017 of problems with clips and fasteners on a steel-framed deck close to the sea¹³. My guide to composite decking around pools covers the rest of the poolside detail.

Are clips faster than screws?

I'd expect clips to be faster once you are in a rhythm, and slower while you learn. One clip per joist crossing against two screws is the arithmetic, and the clip also sets the gap, so there is no spacer to move along. Owner reviews on ProductReview back up the ease. A NewTechWood owner called Darryn added a note to a review in August 2025 that "Concealed fixing are very easy to put in & use"¹⁰. A couple building their first DIY deck wrote in September 2024 that the narrow-gap clip system was "a great way to secure deck to frame"¹¹.

The counter view is there too. A Whirlpool member who laid a hollow composite in December 2018 said the hidden fixings were easy but "no quicker than a timber deck"¹³. An installer reviewing on ProductReview in June 2026 described two tubes of clips that measured a millimetre apart, which pushed a run of 40 boards about 20 mm out of line¹¹. Check clips from different packets against each other before you start, and measure the running total every few boards. A clip sets the gap, but it cannot tell you the gap is wrong.

Replacing a board later

Face screws win here. Back out two screws per joist and the board lifts. With clips it depends on the system. One clip maker publishes board-removal guides for its clips, and a ModWood owner on ProductReview wrote in May 2024 that the boards were "easy to install & even easier to replace"¹². Not every system has a removal guide, so before you choose a clip, ask the maker how a board in the middle of the deck comes out. Keep a few spare boards from the same batch in the shed either way, because colour can vary from batch to batch.

Colour-matched screws and plugs

Face screws on a composite deck do not have to stand out. Ask the maker or merchant for a screw with a head coloured to suit your boards. Plugs are the other option. One maker's guide for a PVC board points installers to a plug system that fills the countersunk hole⁸. On a picture-frame border, where the screws run in a line along the edge, I'd look at plugs. On a stair tread I'd use a matching screw head and not bother, because a tread is seen at a glance from above.

Whatever the head, one guide puts screws at least 25 mm from the board end and edge so they don't split it, and adds a sister joist at each butt join so every end can be screwed straight down at 90 degrees⁷.

Which to use where

• Field of the deck, grooved board: the maker's clip at each joist, plus the locking clip if the system has one.
• First board at a step or edge: a starter clip or face screws, per the guide.
• Last board at the wall: face screws, pre-drilled.
• Breaker boards and borders: face screws in one guide, clips into noggings in another.
• Stair treads: face screws, with clips as well in one guide. The framing is in composite decking stairs.
• Square-edge boards anywhere: face screws, two per joist, pre-drilled unless the maker's screw says otherwise.

The joist centres under all of this are in my guide to joist spacing for composite decking, and the end gaps the clips cannot set for you are in expansion gaps in composite decking. The order of work is in how to install composite decking, and the borders that take most of the face screws are in picture-frame borders on a composite deck.

What I'd do

Buy the clip the guide names, in nylon or stainless if the deck is near salt or chlorine, and buy screws for the edges in the same order. Order a few extra boards and keep them. If the deck is small and you expect to pull boards up for services underneath, I'd go with a face-screwed square-edge board for the easier life. Use the boards calculator to count boards and clips for your layout before you order.