It’s the end of summer and many homeowners are no doubt realizing they didn’t use their backyard nearly as much as they wanted to this year. They’re thinking maybe a deck will help get them outside more. Or they already have a wood deck and realize the boards are tired, or that the regular maintenance of cleaning and staining is becoming too much.

Right now is a great time to install a new deck. Cooler days mean it’s easier to work outside and if you’re working with composite decking, you’ll need to account for expansion less than you would on the hottest summer days, making installation easier too.

Spahn & Rose supplies composite decking material from a number of high-quality suppliers, including Trex. Trex offers a high-performance product with deep woodgrain patterns and luxury colors to suit every homeowner’s taste. And its products are easy to install, making it a great option for contractors to work with.

This guide walks you through the basics of Trex Decking installation for planks and railings. Additional how-to resources are available on the Trex website, including a detailed installation guide.

Prep Work: Storage and Structure Supports

We’ve talked about the best way to store your composite decking in this blog post. As you’re getting your materials ready, be sure to store your Trex decking planks and rails on a flat surface and out of direct sunlight to help minimize expansion before you install.

Next, you’ll need to set your structure supports, including joists. Trex requires that all deck planks be supported by at least three joists, with additional support built-in under areas of the deck that will be carrying heavy loads, like large planters or hot tubs.

Once your joists are in, you’ll need to install any necessary 4” x 4” support posts for railings, as these will be fixed to the joists before the decking planks are installed.


How to Set and Install Trex Decking Planks

While it can be tempting to start fastening planks right away, Trex recommends that you completely lay out the decking over the joists. This not only helps you make sure you manage your cuts so you don’t have too many small pieces at one end; it also helps your client see the overall color variation from the woodgrain, and identify places where those variations are too similar or visually jarring.

Many homeowners choose composite decking because it lasts longer than wood with less maintenance. It isn’t prone to rotting, warping or fading the way wood is. But composite decking material will still expand and contract in the elements, and you will need to include space to permit this when installing Trex decking.

For Trex decking planks, the recommended end-to-end and side gaps range from ⅛” to 3/16”, according to the temperature on the day of installation. The gap against the permanent structure ranges from ¼” to ½”, according to installation temperature.

If you’re building a deck with metal framing and joists, it will expand differently than wood. As a result, minimum gapping for your deck board will be different as well. Refer to the appropriate installation guide for details.

Once you have your whole deck laid out and are happy with the patterns, it’s time to start fastening your Trex decking planks in place.

Trex Hideaway Universal Hidden Fasteners are the recommended fastener for all Trex products. They are designed not to crack or shred the composite material during installation. Trex composite planks are designed to conceal the fasteners in grooves along the sides of each plank, keeping the deck surface clean and uninterrupted.

Screw the end of each board twice into a joist. End-to-end junctions should be fastened to two joists for extra security.

The Best Way to Install Trex Decking Railing

Once the planks are in place, it’s time to install any railing. Many building codes will have minimum requirements for railing heights and spacing, so make sure you’re familiar with these before you start.

Trex Transcend Railing is the company’s highest-performance railing line. It offers more colors for more components than competitors and gives homeowners the opportunity to mix and match colors and profiles to get the exact look they want.

Transcend Railing can be installed in six different configurations ranging from classic crown railing to a modern cocktail rail using Trex decking planks instead of post caps. Homeowners can choose from classic composite balusters, round or square aluminum balusters, or swap out balusters completely for glass paneling or another custom solution.

If you’re installing railing, your support posts must be installed after the joists and before the decking planks. Trex post sleeve skirts and post sleeves are designed to fit over these 4” x 4” posts and will slide right down to the deck surface.

Next, you’ll need to install railing support brackets. Trex offers a template to ensure that these are fastened exactly where they need to go. If you’re working without a template, mark the post sleeves at 5½” from the base and either 35 1/16” or 41 1/16” from the base, depending on the height of your posts. Use the wood screws provided to make sure the post sleeves don’t crack.

Once your support brackets are in place, you’ll need to measure the distance between the posts before cutting your rails. Trex recommends installing posts at 6- or 8-foot intervals, but measure to be sure and cut both your railings and baluster spacers as needed. If you’re installing staircase railing, you’ll also need to mark the angle for the railing cut.

Bottom rails need to be supported, so you’ll want to attach a foot block. Then you’re all set to attach the bottom rail into the railing support bracket, using the self-tapping screws provided. Attach the top rail the same way. Finally, you can snap your baluster spacers into the bottom rail, and place an inverted baluster spacer on top of it for later installation in the top rail.

Balusters should fit in place through the spacers. You’ll need to install them at an angle into the bottom rail and then slide them into place in the top rail. Don’t worry if they’re not fully straight or won’t stay completely upright. The next to last step is to slide those inverted baluster spacers up and snap them into place in the top rail, which should fix your balusters in place.

The final step to installing a great looking railing is to place the caps on top of the support posts. Use a silicone or PVC adhesive to secure it into place.

Contact Spahn & Rose for a Free Estimate

A composite deck will look great for decades, and homeowners will get to spend more time enjoying their outdoor space and less time maintaining it. Trex composite decking is a versatile product with color and configuration options to match any vision.

For help getting started, contact your local Spahn & Rose representative, or work with your clients to try out the Trex Deck Designer and give them the deck of their dreams. Your Spahn & Rose representative can provide a free estimate for decking materials and create a building materials list.