How to Install Trex Signature® Railing & Pre-Assembled Panels


Let's walk through installing pre-assembled Trex Signature® Horizontal Railings and Trex Signature® Stair Panel Railings. Whether you're a DIYer stumped by installing deck and stair railings, or a long-time deck builder new to Trex, the following guide will help every step of the way, from unboxing to completing your deck with safe and secure railings. 

Trex railing panels for decking and stairs are available in 36" and 42" heights. In most states, the railing of a deck attached to a single-family property must be at least 36", while commercial and multifamily properties require a minimum of 42" high. However, we recommend checking your local building codes, as some municipalities have different regulations. 

Before you begin installing your pre-assembled railing panels and stair railing panels, you should have all your posts installed. Also, this is a good time to ensure you have all the tools and materials needed — they're listed below our step-by-step installation instructions.

Disclaimer: Instructions provided by Trex® are based on the build specifications that Trex® demonstrated in the Trex® Academy video series and are not universal to all homeowners’ projects. A homeowner’s build may vary from Trex’s instructions based on the homeowner’s local municipality requirements, individual design preference and project specifications. For questions or assistance needed during your project, please reach out to

For any home project, be certain to follow local code and permitting requirements.
© 2022 Trex Company, Inc.
01. Horizontal Rail Positioning 03:00
02. Cut Your Railing Panel to Length 03:58
03. Set Your Panel Into Place 05:00
04. Installing the Top Cap, Bracket Covers, and Post Caps 05:47
05. Racking Trex Signature Stair Panels 07:10
06. Clamp and Mark Your Trex Stair Panels 08:20
07. Mark Bracket Locations 08:45
08. Cut Your Trex Signature Stair Panel to Size 09:28
09. Install Brackets and Align Panel for Fastening 10:16
10. Align and Fasten Your Stair Panel 11:16
Step-by-Step Instructions
Chapter 01: Installing Trex Signature® Horizontal Deck Railings
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Step One: Horizontal Rail Positioning 

Place your pre-assembled railing panel so that baluster spacing is roughly the same on both sides. This means the space between the closest baluster and the post at either end should be equal. Eyeball this at first, then clamp your railing panel in place and take a moment to measure the spacing. Adjust as necessary before you mark your cutting point. Remember, you need a minimum of 1 ¼ inch space for the baluster to clear the bracket. 

Pro Tip

You will need to use a light-colored marker to show up on the black railing – silver works particularly well.

Step Two: Cut Your Railing Panel to Length

Secure your panel to your sawhorse using your clamp, and extend the cut mark you made earlier using your speed square as a ruler. Next, cut the top and bottom rails at both ends using a circular saw with a wood-cutting blade. Remember, the finer your blade, the cleaner the cut. Remember to put on your ear and eye protection before you cut.

Pro Tip

Adding Painter’s tape on the shoe of your saw will minimize scuffs and scratches on the surface of your railing panels.

Finally, you need to cut access holes in the anti-rattle strip at the top of your railing. This is to allow you to fasten your railing to your brackets and posts. You'll have to backtrack later if you don't cut them now.

Step Three: Set Your Panel In Place 

Start this step by placing your anti-rattle adhesive strip on the top surfaces of your two bottom brackets. 

Next, line the ends of your railing up with the brackets on your posts and set them into place. Once they're sitting comfortably, use the windows you cut in the anti-rattle strip to drill two holes through the rail and the bracket. Repeat at the other end. Use a 7/64" drill bit for this.

Next, secure the top rail to the brackets on the railings at both ends with the provided stainless steel screws. Remember to adjust your drill to a lower setting to insert the screws. Otherwise, you risk damaging the thread on your screws or the top rail and bracket.

Step Four: Installing the Top Cap, Bracket Covers, and Post Caps 

The top cap – which goes over the top rail – has to be the same length as that rail. Measure it, mark it, and cut it before you set it on top of the rail, align the ends, and tap it into place with your rubber mallet. You should hear the top cap click into place, but you can test it by pulling along both edges. 

Next, add your bracket covers. The top covers are flexible — just press and click them into place over the top of your bracket. The bottom bracket covers are more rigid, with a tab at the post side. Set these in place, and use a piece of wood to tap them into place as the space between balusters is too small for a mallet or much manual dexterity. Repeat for all brackets. 

The post cap is even easier. Simply set it on top of your post, make sure it's aligned and level, and tap into place with your mallet.

Trex Signature stair panels are installed in a very similar way to horizontal panels. They do, however, need to be racked, the cutting can be a little more complex, and you have to install the brackets on the posts. 

Step One: Racking Trex Signature Stair Panels

Racking means changing the angle of your railing panels to accommodate the angle of your stairs. This is why there are no pre-mounted brackets on stair posts — the angle determines the necessary bracket height.

To begin properly racking your stair panels, locate a piece of scrap decking. Mark and cut it to fit snugly between your posts, running along the nose of your stairs. This will be your platform for marking and will help you determine the correct bracket height. 

From here, you can determine what angle your stair panels need to sit at. 

Now it's time to set the panel. Place your railing section on top of your scrap decking board and adjust to work out the correct placement. Look for even spacing between the baluster and post on both ends, and make sure your balusters are running parallel with your posts. 

Step Two: Clamp and Mark Your Trex Stair Panels

Clamp and mark your panels, making sure the space between the post and the closest baluster is equal on both sides. Remember to measure at a right angle to posts, not at the angle of the stairs and railing. Adjust if necessary and measure again. 

Step Three: Mark Bracket Locations

When your spacing is correct, mark the location for your brackets on your posts. To do this, use a pencil to record where the bottom of the rail intersects your post. Repeat at all four meeting points of post/rail. 

Step Four: Cut Your Trex Signature Stair Panel to Size

Take your stair railing over to your sawhorse to cut. Straighten the panel out before cutting so the rails are running away from you directly at 90 degrees, then clamp. Cutting at this angle will help you to avoid running into the rails as you cut. 

Move each cutting mark ¼ inch in to accommodate bracket size. Transfer the mark to its new location with your speed square for accuracy. Again, use a circular saw with a fine blade to make all four cuts. Your brackets will cover the cut straight-cut edges once your Trex stair panels are fully installed. 

Step Five: Install Brackets and Align Panel for Fastening

Remember, the posts on your stairs don't have brackets yet. These are key before you attach the railings to your stairs. 

To install the brackets, extend the line you marked on your post in pencil and place the bottom of a bracket on top of each line. Mark the screw holes in each bracket with a pencil and remove the bracket to drill pilot holes where you have just marked. Again, use your 7/64" drill bit. 

Next, place the brackets and use the stainless steel screws provided to attach them to your posts where the top and bottom rails of your stair panels will sit.

Step Six: Align and Fasten Your Stair Panel

The final step for installing your Trex Signature Stair Panel is racking the panel again, making sure it is at the right angle for your deck stairs and also fits into your brackets. If it doesn't fit when it is at the right angle, you might need to recut your panel or adjust the positioning of your brackets. 

When racked, set the stair panel into place. Then, drill through the side of the brackets and into the rail. Finally, add your bracket covers and the stair panel top caps and post caps. Installing these is the same on a Trex stair panel as it is on Trex horizontal deck railings. 

Finally, if you have scuffed or scratched your Trex railings or stair railing while assembling, you can order spray paint or a touch-up pen. 


  • One or two clamps

  • A speed square 

  • A light-colored marker pen (silver is recommended)

  • A sharpened pencil

  • A circular saw with a fine wood-cutting blade 

  • Snips/shears

  • A measuring tape

  • A heavy rubber mallet

  • Drill

  • Drill bits


  • Spray paint and/or a touch-up pen 

  • Painters' tape

  • Thick, fingerless gloves


  • Pre-installed posts (end, line, and corner)

  • Post caps

  • Two-piece post covers

  • Screws

  • Adhesive strips 

  • Top and bottom bracket covers

  • Pre-assembled horizontal panels

  • Rail brackets 

  • Trex signature stair panels