Trex and Concealed Deck Fastener Systems
When we bought our house in mid-2004, we tore down a back yard deck and patio cover that was falling apart. This left a large (11'x25') dirt area, as well as some holes in the cement patio, which had been poured around the deck supports.
In February 2005 we build a new 12'x32' deck. After doing some research, we decided on Trex Accents 2x6 planks for the deck, with a redwood patio cover comprised of 2x2s with 50% coverage (i.e. if you covered the deck completely with 2x2 strips, you would remove every other one). Not being wise in the ways of construction, we hired a contractor to do it for us.
We wanted to use one of the concealed deck fastener systems, because it looks better than nails or screws. It can also improve the lifespan of your deck by reducing moisture penetration in wood. I found it difficult to find information on the web about these systems, except for varying amounts of information provided by manufacturers or resellers, but I didn't find any warnings about the products either.
The products we considered were from Deckmaster and Tiger Claw. The Deckmaster system uses screws that attach from beneath. Tiger Claw's TC-3 clips, recommended for use with Trex, are hammered in from the sides and screwed down from the top.
|Tiger Claw TC-3||Awkward Places|
Because our deck is fairly low, and parts rest on concrete steps outside two sliding glass doors, we decided to use the Tiger Claw. The reason was largely economic: based on the circumstances, it was less labor-intensive to use the Tiger Claw. Our contractor hadn't used the two together before, but it seemed pretty straightforward. This, unfortunately, turned out not to be the case.
If you're building a deck out of wooden planks, and you find a warped board, you discard it or just use parts of it. With Trex, the boards have a lot of flex. This can be a desirable feature, because it allows for some very creative curvy projects. The trouble with using them on a straight 32-foot deck is that they tend to want to bend. If the planks were screwed in directly, from above or below, you could put them where they needed to be and then fasten them. With the Tiger Claw product, it's not so simple.
On each row, you pound the clip into the board that's already down, then you pound the next board sideways onto the clip. In the words of the OrePac Trex Pocket Guide, "More force is required to drive a nail in Trex decking than with regular wood." When you pound a nail, you're putting a lot of force onto a small area. When you're pounding a TC-3 spike, you're hitting two fat nails at the same time. The real trouble comes when you have to pound the board onto the spike, because you can't hit the board directly or you'll chew up the plank. You have to lay the board down, put a 2x4 next to it, and then hit the 2x4 until the Trex plank is fully seated.
It's hard to make subtle adjustments, because you have to be subtle with a large hammer. With real wood, the spikes go in more easily, and the board doesn't want to bend. The result of all this was a set of planks that didn't run true for the length of the deck.
|Not quite straight||(click for full image)|
You can see it swerves a bit to the left near the top of the picture, about where the jacket is. It's a little easier to see in real life because you can move your head left and right and re-focus your eyes as you sight down the lines. The swerve started because the face of the house isn't quite flat. With more conventional construction this would be easy to correct by adjusting the spacing between boards, but the combination of Trex and Tiger Claw makes it difficult to get the spacing just right.
This is not to say that it's impossible to get a straight-running deck with Trex and Tiger Claw. It's just harder than it would be with other choices. On the left side of the images you can see wood shims being used to modify the spacing.
If I had it to do over, I would not have used side-driven clips with Trex. About halfway through the project the contractor called me down and asked what I wanted to do. He was frustrated at his inability to make the deck come out like it should, and asked if I wanted to tear it out and start over. Either try again with the TC-3 clips, or switch to a different system. After staring at it for a while I decided that it wasn't worthwhile -- the swerve isn't that severe, and with a few pieces of furniture on it the sight lines will be broken up anyway. I was also a bit concerned that the Trex planks and joists might be weakened by having spikes and screws pulled out and re-inserted.
I'm disappointed that it's not perfect. With a table and chairs on the deck, though, I doubt anyone (including me) will notice.
For the curious: the planks are Trex Accents, which have a wood grain pattern pressed into them. It looks a lot more like wood than classic Trex, which bears a strong resemblance to concrete slabs. The color we chose is called "Saddle". I'm very happy with the way it looks. We were a little hesitant to mix and match Trex and natural wood, but I think it came out well. The 2x2s are "con heart B" grade redwood, treated with Penetrol.
|Furniture sold separately||Interlocking 2x2s|