Award Winning Composite Decking

Fast National Delivery

Samples Available

Tried, Tested & Top Rated

Composite Decking Clips

Composite Decking Clips

Posted by adrac on October 23, 2022

In this article we will go through the types of composite decking clips available and what to look out for when choosing the right clip for the composite decking boards.

What are the types of composite deck clips

  • Starter Clips

Starter ClipsV

Basically, starter clips used to start laying the deck, the U shape allows for a board to be held in place without an overhang. The stainless steel clip provides strength and rigidness to hold the board in place because the T fasteners are attached to the opposite side of the decking board and into the joist.

In addition, a starter clip is placed on the outer edge of where the first deck board row will be laid. Placement of 1 starter clip every 250mm or every joist apart and each corner is required. Additionally, the same would be required for the final row of boards.

  • Concealed T Fastener Clips

The T fastener clip is a fast and durable product that provides a 6mm gap between the boards and holds down the boards. Placing on every joist and ensuring to use a clip per board when 2 boards join instead of using one clip over two boards. Therefore, the T fasteners come with the option of silver stainless steel screws or powdered black screws at 30mm long. Also This allows 20mm into joist and 10mm through the clip itself. Specifically, Deckorum only use Grade A material providing the best quality of high density polyethylene making sure the boards stay fixed in place.

On the last board, the T fasteners are slid down the ginnel side of the board to allow enough space to place a clip through. Place the last board within the starter clips and sit the board flat. After that, place a screw in the T clip to allow grip and slide down the length of the board up to each joist, starting with he furthest joist first. Doubtedly, if space does not permit this option you may need to screw directly into the board to the joist. A 60mm countersunk screw through a pre drilled hole every 1 metre apart is sufficient.

  • 3 mm S Type Clip

The visually appealing 3mm S Type Clip allows a 3mm gap between the decking boards making the gap barely visible. Also a 25mm stainless steel screw secures the 3mm S Type clip to the material. Similar to the T fastener the S Type clips is placed between the boards but here the side with 2 edges slides under the deck board and a single screw is placed into the clip through to the joist.


On the last board sliding the clips down the side is not an easy option. In addition, for adequate attachment, use a 60mm countersunk screw through a predrilled hole every 1 meters.


  • Gap between decking boards

A gap is important for composite decking which allows for expansion and contraction of the boards. When you receive your decking boards allow them to clematises for 48 – 72 hours allowing the boards to absorb atmospheric moisture and adjust before installation. A guide is also to install when warmest as the boards contract most when hot. However, movement is minimal and the clips provide a hassle free install taking into consideration the boards will have some expansion and contraction. Allow gaps on the outside edges of the deck of approx. 2mm per every metre of deck board.


How many composite decking clips

Based to fit 1 composite decking clips on every joist it can vary how many clips you need depending on the spacing of your joists. That is the recommended joist spacing for composite decking is 250mm to 300mm. A table to illustrate the number of clips based on joist spacing

Joist Spacing Centre to Centre Number of Clips per SQM Number of Clips per 10 sqm
250mm 24 231
300mm 20 191
350mm 17 172
400mm 15 151
450mm 13 134


If you have cuts and joins where 2 boards meet we would recommend a 10% allowance to allow a clip on each board.

Click here to view our range of clips