No immediate reason to think the decking will do the same if it is properly installed. How is the railing installed? Is that an approved Trex method for railing cap?

I'm not pro like milkwork an, but at our last house we had a tree deck that held up beautifully. I do recall in builder discussing how it needed to be installed, but don't recall the specifics. Based on that though, i bet it is an installation p, not materials issue.

The end of the cap appears to have lifted, which raises the question of the type of connection...can you contact your installer?

I hope the deck will be ok. This wasn't an inexpensive project. I haven't contacted the installer yet, but he is very reputable. I chose the design out of the Trex catalog, concerning the railing cap and used all Trex Materials. It looks like the board has warped, but maybe it can be fixed. We had it installed end of summer/last fall and I was so happy with it...I used composite because I wanted the low maintenance and for it to last.

Are you sure that is the right type of top for your railing? All trex decks that I have seen have had railing caps like these. https://www.decksdirect.com/transcend-individual-rail-by-trex.html 

Was enough expansion gap left in the materials? Plastic expands and contracts more than wood does. And this is just now getting to be real summertime, with real heat. Lots of things start to warp a bit in that.

Can’t tell where you live but I’d never use composite b/c of warping in my harshly hot TX weather. In fact, no plastic anything for me. Wood can also warp but at least not as expensive to replace the warped piece. Those pretty plastic fences that were so popular for a while? What a joke! Became brittle, warped, mostly gone these days.

some Galveston resorts readily converted to composite decking and in 2 years they looked horrible, warped and/or discolored. Don’t know if they were Trex, but a few years back there were only a couple of makers, so good chance it was a”major” brand. The prettiest composite decks I ever saw were in magazines.

This composite plastic is notorious for this.

Send pics from all sides and bottom to Trek Tech Support and get the fix rolling.

Those are deck boards used to make a cocktail railing, correct? If so, I’m inclined to think this is an installation issue. Look at page 63: Trex Installation Guide

Yes, it's cocktail railing. I'm calling the installer and Trex Support tomorrow. I'm just so aggrivated. Thanks for the advice all.

The installer also did not match the grain in the deck board ends.

"The installer also did not match the grain in the deck board ends."

What does this mean, please?

You are not OP. Google some terms.

Deck board ends, i.e. butt joints. Grain continuity is completely lost.

strategery:

Please cite any manufacturer or trade association documents that recommend attempting to match the grain on deck butt joints. In fact, any source anywhere other than you. Thanks in advance.

Who's "we", the unlicensed "fake pros" who the industry is trying to get rid of? Lots of them here, that's why the "pros" have a 20% accuracy rating.

@Tundra - Everybody is welcome here and the info is all free, just like the rest of the interwebz.

Want expert advice?, go pay for it. Want stories of experts being wrong?, come to GW and read the stories. It's a wonderfully chaotic mashup of personal opinion, argument, golden advice, FUD and crap. If you want only experts, go to contractortalk.com and stop your whining.

Wow. I didn’t mean to come off as whining, strategery, Where I live in the South, composite isn’t used a lot vs wood, so it was a big decision for me. And, I do love how it turned out, so I guess I was surprised when I saw it. I always get a lot of good info from the different forums I read here so I thought this was a good place to ask. I never thought about the deck boards matching. That really doesn’t bother me and I’m not so sure if they did that would look natural?...I don’t know.

I contacted the contractor that installed my deck and he come out and looked at it. From what I understood something broke inside of one of the Trex posts, I don’t know if it’s a bracket or exactly what, but you can slide the bottom piece up that supports. I’m not sure why but either way he is going to fix it. I attached a pic (I put the piece of brick there to show how it slides up and shouldn’t). Maybe that caused it to buckle, idk, I’m a female that admittedly knows nothing about things like this. Anyway, I really do appreciate all the good advice as it gave me an idea what could have happened and where to start. The support shouldn't have broke, and if it turns out it isn't an installation issue I will definitely be contacting Trex. Thanks again.

Jeff, you don't have to be a ****. Putting a Trex deck on OUR house was the biggest financial investment we've made in our property; now it looks like crap. Why don't you come out of your little world for a moment...