How To Install Trex Composite Decking [Step-by-Step Guide]

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install trex composite decking

Trex composite decking is one of the leading decking products in the country.

They have a large market share, competitive pricing and an incredible selection.

On top of their decking products, you can also find Trex products for your entire outdoor space, from pergolas to lighting,

Trex really is a one-stop shop for your new deck. One issue many new owners face, though, is the proper way to install a Trex Composite deck.

This article will focus on the brand and it’s materials and show you everything you need to know to install your deck and have one of the most beautiful backyard spaces on the block.Read on to learn it all and start your DIY deck install today.

Top Reasons to Choose Trex

Trex decking has a long list of reasons to buy and build. If you are already in possession of their products, you know. If you haven’t purchased yet, here are reasons why you should.

  • Termite resistant. Composite decking, like Trex, is not made of wood, so termites and other wood boring insects won’t make your deck their new home.
  • Rot and decay resistant. Composite decking won’t rot, warp, splinter or crack, unlike wood decking.
  • No staining. You won’t need to apply staining, sealant or paint every year like you do with traditional wood decks.
  • No fading. Trex decking won’t fade or stain even in direct sunlight, for at least 25 years, if ever.
  • Installs just like real wood. You can use your normal decking screws, nails and tools when working with Trex composite woods.

Buyer’s Guide: Everything You Need for a Complete Install

buyers guide trex composite decking

Before you pull out the drill and screws, you need to ensure you have everything you need to build (and finish) your new deck.

Below are several things to consider before you start the building process.

Decking Material

Obviously, if you are going to build a deck, you need the boards. However, there is a lot more to a deck than just the planks you walk on. You also need to consider the frame and joists, as well as any designs you intend to implement.

Some designs, such as checkerboard or tile, may require closer spacing, additional framing joists, etc. You need to ensure you have more than enough Trex composite boards, framing and connectors to finish the job.

Color and Style Options

Style is important and it is now easier than ever to make attractive composite decks. With the various styles and colors available you can make intricate designs. If you are more into patterns, having two shades of the same color can make that pattern pop.

Choosing the right colors and widths of boards will go a long way to a smooth and easy project.


Just because you can use standard deck nails and screws, doesn’t mean you have to. Hidden fastener systems also work with Trex decking so you can have a seamless surface without pesky screw holes.

Choosing the right style for your needs may take some research. You also want to ensure that the broads can accept the fasteners you choose. Slotted biscuit fasteners, for example, require slotted planks.


Not all decks need a railing. However, if you have steps, a steeper drop off, or just want the nice and complete look that railings give you, now is the time to prepare.

Make sure you have enough railing slots, toppers and corner posts to complete the job and double check that they all match in color, size and mounting options.

Steps and Facings

Most decks will need steps either to and from the yard are up to the house. Depending on how you plan to add your steps, you may need more or less material.

What is important to keep in mind, though, is that you should spend the time and money on proper steps. While you can make your own steps, getting the treads and risers will go a long way to improving the overall look.


Now that the actual decking materials are covered, it is time to think about other features. Cladding is essentially siding for your house. Made of the same composite material, cladding can add a touch of style and sophistication to the deck side of your home.

You can continue your deck design or pattern up the wall, cover the whole side of the house or only part of it. Either way, it is an extra expense that can make a world of difference to the finished look.


Nothing is better than spending time on your new deck on a nice sunny day. Except when the sun is full, hot and in your eyes. A pergola can help add a touch of style to your deck and help keep the sun from beating down on you.

Trex has pergolas that you can buy or build. Each one is made from the same composite material as your deck, so you are sure of a uniform look.


Entertaining on warm summer nights needs the right lighting, too. Trex deck lighting is a great addition to your final project. Bringing everything together, the right lights will add ambiance and decoration to the space.

How to Install Trex Decking

how to install trex decking

Measure twice and cut once. That is the mantra you should live by while installing your new deck. Before you ever begin you need to understand your deck area.

Where will it set and what is the ground around the deck like? Slope, cement footings, framing, size, space and everything else should all be considered long before you place your first board.

This short video will show you the 5 things to consider before you start the project.

Each type of Trex boards (Transcend, Enhance and Select) will all have a slightly different installation method. You can learn about the differences and all things Trex has to offer in our Trex Composite Decking Review here.

We will cover the basic installation (no deck lighting, cladding or special aspects like circles or intricate patterns). Trex offers a PDF that covers all installation steps for each board type and more. The latest version will have all updated measurements, stats and tool requirements.


Long before you even purchase your deck materials, you need to run a few checks. First and foremost is to inquire about any permits that may be required. A quick trip to city hall should get you sorted. Each city, county and state has different laws regarding new construction, so you will need to ensure your deck is in compliance.

Next, you should check with your HOA (if applicable) about size restrictions, colors or any other concerns. Once all that is sorted, you need to call the utility companies and ensure the area you plan to build in is free from underground lines, wires or drains. Most areas have a short-code number to call (such as *811) to get an inspection completed.

Finally, once you are actually approved and ready to build, there is more preparation. First, you need to outline your deck on the ground, check for slope and if you are installing a drainage system ensure there is room and the proper pitch for it.

Once your decking materials arrive, many find it helpful to loose lay the boards directly on the ground to ensure coverage, look and layout are all fine. It is also helpful to determine that you have enough material for the job.


The first part of any deck is the framing. This is the foundation of your deck and one of the most important parts to get right. You will need to use cement feet to secure the elevated posts into the ground.

Dig your holes and fill with your cement mix. While the mix is wet, but stiff, insert the elevated posts and ensure they are level. Once the cement dries, test the security of the posts and that they won’t wiggle or come free.

Now, you can install the framing. Trex recommends metal framing, which makes the process faster and easier. You can get the framing pre-built or install it piece by piece yourself. The beams will mount to the elevated posts. Your joists will set across the beams.

Normally you are looking for 16- to 24-inches spacing between joists. However, your deck pattern may require closer or further spacing.

Installing the Boards

Once the framing is in place, secure and set, you can start installing the boards. You will want to start on one edge (usually house side) and work towards the other side. Of course, depending on your pattern or design, you may end up working to a set point, the center or a different edge.

The first thing is to secure the end board mounts. The slotted edge of the board will slide into the mount. Ensure the board is flush with the edge of the frame and that the edge mounting brackets are secured.

Using a scrap piece of board, install the hidden fasteners to the other edge of the first board. The scrap board will help ensure the fasteners are flush and secure.

Remove the scrap board and push the second board into the fasteners. Add new fasteners to the open side of the second board, again with the assistance of a scrap board.

Repeat until your boards are all in place and secure. When you reach the other edge, it is advised to use a straight board with no slots.

You will need to add the slots to the inside of the board to use the hidden fastener. Trex has a router bit that will make a simple groove just for this purpose.

After the final surface board is in place, it is time for steps and.

Adding Steps

When installing stairs, you will need at least 4 stringers. A minimum stair width is 36 inches. If you exceed 36 inches, you will need to add a 5th stringer.

Most steps are also 8 inches high, so it is ideal to use 1×8 inch risers. These will mount directly to the stringers. Once the risers are in place you can add the stair treads.

The treads will install in the same manner as your deck boards. You will start by using a starting row of fasteners to the top back edge or each stringer. Slide the first board into the fasteners and secure on the other side with new fasteners.

The second board will then push into position where you can secure the fastener screws for a secure fit. The front edge of the second board should be nailed into the stringers for security and durability.

Like the final board on the deck, you may want to use a straight board and use a router to add the grove for the fasteners.

If you are installing railings, either around the edge of the deck, on the stairs, or both, you will need to add a step to the deck build. Adding rail posts can be done fascia side or inside the framing.

Either option is fairly simple, but you will need to cut the boards on the deck around the posts. Add the proper sleeves and ensure your spacing is correct.

Once the posts are in place you can finish your deck surface. Afterwards, use the railing fasteners on the posts, cut your railing to match the size and install as directed (each railing system is different in exact mount procedures).

After the rails and rail posts are in place, caps can be added (and lighting). Your deck is almost complete!

Finalizing the Project

Once the deck build is complete, you will want to wait at least 24 hours before adding your furniture, grill and running around on the deck itself.

This time is for acclimation, resting and expansion of the boards. While there shouldn’t be any movement, you need to allow the deck time to set and expand. After 24 hours have passed, run through and test each board.

You want to check for loose fasteners, excessive gaping and any uneven areas. Adjust the fasteners as needed, and after all screws have been double checked, you are ready to use your deck. Congratulations!

Care and Maintenance of Your New Trex Deck

care and maintenancce trex deck

After installation care is important. Even though composite decking doesn’t need to be sealed, painted or stained, you still need to care for the deck to make sure it lasts as long as promised.

Luckily, maintenance is low and you only need to do a few things. Most of the items can be done as needed, though a regular schedule for cleaning and maintenance is always beneficial.

There are different instances when you will need to clean your deck. However, prevention is better than removal when it comes to things like mold, stains and scratches.
  • Use warm, soapy water and a scrubbing mop or brush to remove dust, dirt and debris.
  • Never use solvents or acetone on the deck surface.
  • Leaf blowers can remove larger, dry debris.
  • Do not allow leaves, paper, rubber or other debris to set on the deck for long periods of time. Moisture can accumulate, leading to tanning or mold growth.
  • To maintain the stain warranty, you must clean up any grease, food or oil within 7 days. However, to prevent mold and insects, these should be cleaned up immediately.
  • Use only calcium chloride or rock salt to melt ice and use plastic shovels to remove snow and ice.
  • Hard water stains can be removed with vinegar. However, you must rinse well and immediately. Try not to use hard water to rinse. If you must, dry the area directly after the rinse.
  • Using a pressure washer is okay. However, you must only use the fan sprayer attachment and not greater than 3000psi. Do not use the washer to scrub the boards. Instead apply the soap with the washer, scrub with a hand brush and rinse with the sprayer.

Frequently Asked Questions

faq installing trex deck

In this section, we answer some of the more common questions about Trex decking and composite wood in general. Please use the comment section below the article if you have further questions or concerns.

Q. How long will a Trex composite deck last?

  1. Trex decking is warrantied against damage, issues and staining for 25 years. However, with proper care, maintenance ans normal usage, you can easily see 30 to 40 years without issue.

Q. How much does a Trex deck cost?

  1. The price for decking and materials will vary from state to state and even between cities. However, on average you can expect to pay between $9 and $16 per square foot for a full Trex deck.

Q. Is composite decking better than wood?

  1. Composite decking is made from recycled material, It doesn’t contain any wood so it is better against the elements and insects. Termites, for example, do not eat composite materials. Composite decking, like Trex, doesn’t need to be painted, stained or sealed, either. Natural wood will not last as long as composite decking, either, making composite a smarter choice.

Q. Is Trex eco-friendly?

  1. Trex is made from 95% recycled material. They also enforce green manufacturing processes where possible, making Trex an eco-friendly solution.

Q. Can I paint or stain Trex decking?

  1. Painting and staining Trex decking is not recommended. While it is physically possible to do so, there is no need. Trex coloring is throughout the entire shell of the board and never requires stains or sealants. Using these on your deck will void the warranty.


Trex composite decking is a great decking solution for many reasons. One of those reasons is the fairly simple installation process. Because the install is DIY friendly, you can save a lot of money on labor by taking the job on yourself.

Everything from framing to the railings, lighting and even cladding is easily added to your home and yard. For a beautiful addition to your home, give Trex composite decking a try. You won’t be disappointed.

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Nora has more than 5 years experience in the floor covering industry, acquiring vast knowledge about installation and material selection. She now enjoys working as a writer and an interior decorator. Her work has been featured in The Spruce, Homes & Gardens, Southern Living and Real Homes. See full biography here.

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