Every great outdoor living space starts with a good plan and a solid foundation—which is what our decking series is all about. In this series, we sit down with our good friend Kevin Kunka of Trex Company to cover some of the ins and outs of executing a successful decking project. Trex is the world’s largest manufacturer of wood-alternative decking products and a veteran in the outdoor living industry.

In today’s video, we’re talking all things fasteners. There are so many options when it comes to fastening manufactured decking boards, and Kevin helps us understand the differences and nuances of some of the most popular products. Check out our interview above or read the recap below.

Hidden fasteners

The Trex Hideaway clip is a very popular product, and although it is designed specifically for Trex products, it gets used with a wide range of grooved decking boards. The big advantage of using a clip system like this is reduced installation time and improved aesthetics. The clip itself is glass-filled nylon that attaches to the side of the board, then screws in through the top with a stainless steel screw. One feature that makes this clip so popular is a vertically installed screw, which allows you to remove the clip and replace a board in the middle of your deck if needed (other hidden fastener products require you to start removing boards at the edge of the deck and work your way towards the board needing to be replaced).

Connector clips

Connector clips—also called starter clips—are designed to fit the groove on one side of the board. The clip can be attached to joists next to the house allowing the first board to slide into position.

Screw and plug systems

The Cortex hidden fastening system is a slick solution that adds some extra strength while appearing relatively invisible. Matching plugs are available for many of the leading brands of manufactured decking. Installation is simple: Use the Cortex setting tool to drive the Cortex screw vertically through the deck board into the joist below. The setting tool will both drive the screw and create a shallow, perfectly sized hole for the Cortex plug. Then, just gently tap the matching plug into place. This is a popular option for perimeter boards, stairs, planter boxes, benches, and any other application where you’d like a hidden fastener but want boards to be a bit more secure.

Traditional screws

Screws have come a long way in recent years and there are quite a few solid options in this category. Decking manufacturers will often provide a list of screws that have been approved for use with their boards, so be sure to refer to your installation booklet. A word of caution if you decide to go outside of your manufacturer’s recommendations: They may not seat correctly and could create a dimple. They’ll still hold your board down, but could create challenges later and may not be the most aesthetically pleasing solution.

When it comes to installing the screws, it’s important to avoid overdriving. The smart bit is a handy product that streamlines the installation of traditional screws while protecting you from overdriving. A smart bit pre-drills the hole, then countersinks to the proper depth to create a more flush installation, which creates more visual consistency. 

Best practices when it comes to butt joints

It's very important to pay attention to fastening requirements for capped composite boards, especially when it comes to fastening butt joints. Unlike PVC products, capped composite boards need to be fastened at least an inch away from the end of the board and an inch in from the side. In addition, the screw needs to be installed perpendicular to the deck board (no angles). If you follow these directions with a butt joint on a single joist, it is impossible for your fastener to hit the joist below. 

Instead of driving the screw at an angle to hit the joist (which could cause the board to fracture in the future), the better solution is this: Add an additional joist (or nailer) so that you can fasten the deck boards per the installation manual. This will give you the best and longest-lasting result. 

There are so many deck fastening options and we’re here to help you feel confident in selecting the right one for your project. To learn more about deck-building best practices and techniques, check out our best practices for deck pre-planning and layout and this guide to installation basics for manufactured decking.