Building Large Gates: Trex

Here at CFC Fences and Decks I am in charge of materials sales and I sell materials to Contractors and homeowners. Customers often come to our showroom asking advice on gates bigger than normal walk gates. Something to keep in mind is with a wider gate the heavier the panel is going to be which will cause more stress on the post that is supporting it. If the post is not sturdy enough to support the gate panel; over time it will pull the post out of plumb (not vertical), causing the gate to not work properly.

Trex material is a very dense material which makes it very heavy a lot heavier than wood gates.  Our Trex Gates that we build in our shop are built with 16 gauge steel welded interior frame, which helps prevent sagging.  To help make the trex post sturdy enough we use a 12 gauge steel post insert that is 3 sided. You will want to make sure you pour the posts at least 30” under ground to make sure it is sturdy enough and use at least 2 bags of concrete to ensure it has a big enough base.  The Hinges are attached to both the steel in the gate panel and the steel in the post with self tapping screws to give it a firm attachment.  On gate panels 6’ or wider I suggest using our thicker steel post insert. This thing is one heavy beast; it is 7 gauge steel on all 4 sides (as the gauge # goes down the thicker the steel).  With larger gates this size you might also want to put two posts for the hinges to attach to and put more hinges on the gate.  You might also consider putting anti-sag cable on it, or depending on the circumstances a gate wheel might also work.  There are limitations on how wide we can build trex gate panels. The widest we can build them is just under 8’ because the longest the material comes is 8’, However; even then we don’t suggest it because of how heavy they are. Keep in mind that custom sized gates are more expensive. We suggest sticking with our standard size gate panels which are for 46-1/4” and 65-3/4” openings.  These can also be combined to make double gates.