# Composite decking



## RussellAP (Feb 21, 2012)

I am bidding a deck building job and a cedar fence on Monday. 
How does this composite material work? Is it hard on your tools? Do I need special blades or anything?

Never worked with it before.

The customer said that her fence is rotting away. I hope there is enough good wood coming up out of the concrete, or I will have to drill new holes. I hate that part and will likely farm it out. But if there is some good wood, I can drill a hole in it, put a case hard bolt through it and loop a chain big enough to slip a 4×4 through. Then all I need is a lever and 3' of concrete will rocket out of the ground. I've done this before and I believe I'm the only one who ever tried it. Of course I was dealing with chain link. I don't know if wood will be strong enough to do this with.

Anyway the main thing is how to deal with composite wood.

Thanks.


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## TenDigitHands (Jul 9, 2012)

Trex, rhino, whatever brand it's still only wood chips impregnated with plastic. It is very easy to cut and router. It also bends easily. The bendability means 2 things, make sure your joists are no more than 16" on center, because the boards sag especially in hot weather. The other part of bendability means you dont have to stick to straight lines, you can actually make slight radiuses.

It's real straightforward stuff to cut, fasteners are another animal.


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## RussellAP (Feb 21, 2012)

J, what about fasteners?


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## TenDigitHands (Jul 9, 2012)

The selection of fasteners is endless, some of your choices will be dictated by the brand name of composite decking you pick. Some brands have a biscut like groove cut down the edge for hidden cletes, other screws have break away heads that disappear into the deck boards. The hidden fastener systems can really raise the price of the job. I've used composite plenty of times, each brand has different characteristics. SOme brands are harder than others, some softer. When installing the softer brands in hot weather over sinking a small headed deck screw works well to hide the fastener, use a smooth face hammer to tap the "mushroom" back flat and it's like it was never there. The harder brands are less forgiving with this technique, and the cold makes this impossible to do as well. In the cold or using harder boards I snap lines (use white chalk, it comes off) and pre-drill/countersink every screw. Lower cost of materials, lots more labor.

When T&M are an issue I prefer this type of screw: http://www.fastenmaster.com/details/product/trapease-composite-wood-deck-screw.html

When budget is less of a concern, a hidden system is what I use: http://media.marketwire.com/attachments/200705/TN-339337_TigerClawfastenerinstallation.jpg

Hope this helps.

Oh yeah, to pull posts I make an A-frame from 2x's and use a come along, wrap a rope around the base of the pole, sink some nails to hold the rope to the post hook the come along to the a frame and the rope - very easy to do, and if there is more than 1 post to replace very portable.


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## Finn (May 26, 2010)

I built one deck of "Trex" and it came out great. I liked working with it. I just screwed it to a wooden under frame with deck screws. Cuts just like wood but with no splinters or tear out. I had 16 foot long 2"x6" trex boards and when I set one on my shoulder the front and the back touched the ground, it sags that much!


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## reedwood (Jan 27, 2011)

just like wood.

I couldn't see the screw mentioned above in the first link, but I can say I used the deck screws that were designed for this type of decking and they work great. small square drive heads, self drilling, same color and small hole. 
The hidden clips are for a young man's back and more labor.

It's funny, only carpenters and architects get off on hidden screw fasteners.

All of my clients expected to see screws and didn't want to pay the up cost. Frankly, I think it makes sense to be able to remove a board easy for repair or replacement, maybe for under deck access.

The one drawback of Trex is it gets real hot in direct sun light on a hot day… I mean HOT, like you can't walk on it. Wood decks can be the same but there is definitely a difference.

Imagine - someday all framing will be made from some kind of composite recycled garbage and milk jugs.

We will have a laser gun that will heat up the two surfaces and spot weld them…. no connectors needed.

drones will deliver the composite lumber and Jimmy Johns lunch in 30 minutes or less.

Table and Miter saws will look like planers - stick a board in one end, punch in the cut and length, rolls out the other. Blade is completely enclosed. Saw Stop goes out of business….Ha! Zing!

Band saws will be CNC laser cutters

Lathes will be 3D printers

shop vac will be dust sensing robots that work at night. clean shop every morning.

It would be nice to have a robot to pull those fence posts, I'll bet.


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## ScottC (Apr 6, 2010)

I used Trex. It was fine to work with. Easy to cut. Heavy to carry. I re-did my smallish 12' x 18' deck with it. No issues with sagging. My deck joists are 2×12 and 16 OC. Used tiger claw hidden fasteners for the decking and brown self-tapping screws for the railings.

My only complaint with Trex is the black spot staining we get every year. I have kept it clean but it still gets the black spots and the cleaning solution they recommend causes it to fade. I've finally found a cleaner that works best, but it still needs to be reapplied at least once a year.

Oddly enough, the railing doesn't stain nearly as bad as the decking. YMMV in building a fence.

I know Trex has a lot of info on their website. I'm sure the other brands do as well.


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## wiwildcat (Jan 10, 2013)

I have used Azek in the past. Solid PVC decking. Easy to work with and lighter weight than composite. The Azek rail system is a pvc over compostite similar to trex. Azek on my deck is holding up nicely over the last 4 years. One plus is that it doesn't seem to get as hot as coposite decking in the full sun. I used special face screws with pvc color m.atched plugs. Hard to tell where the plugs are after installed.


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## Gene01 (Jan 5, 2009)

We used a hidden fastener system for Trex. If it is trex, there will be a groove on each side to accept the fasteners that are attached to the joists with a screw between the planks. If it's not Trex or the groove is not there, the fastener system comes with a router bit , the screw bit and a driver adapter. Very fast install and no face screws.


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## RussellAP (Feb 21, 2012)

J, with 16" centers under it, and the summer sun blazing down on it for 5-6 hrs a day. And a heavy piece of furniture. Won't there be some permanent sagging?


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## Bluepine38 (Dec 14, 2009)

I would recommend no more than a 12" on center joist with composite decking, it just flexes too much.
I used stainless colored torx screws that had a special counter rotating thread on the top 1/2" of the screw
that pulled the mushrooming back into the deck. Used my Delta 12" CMS with a good shop vac attached
to do all the cuts and did not have that plastic fur making a mess. To make most of the deck boards look
good, you do need to route a roundover on the ends. If you feel artistic and like to do a lot of extra joist
work, you can do a nice curved deck with composite decking in warm weather.


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## TenDigitHands (Jul 9, 2012)

Sorry Russell, I live in the Pacific Northwest. I do not know this blazing summer sun you speak of.

But, the sagging - generally your feet can't feel it, but a string line, or your eyes can pick it up. It really shouldn't be an issue when framed 16" OC. You could always go to 12" OC.


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## wiwildcat (Jan 10, 2013)

12" oc joist = no sagging + a stong deck. Last thing you would want is a call back on a deck that has saggy boards or noticable vibration when walked or jumped on.


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## Gene01 (Jan 5, 2009)

Those who suggest 12" OC may be thought of as overly cautious but, I call them prudent.
Here in AZ, 12" oc is standard for composite.


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