Azek ...
I replaced all my trim with 100% PVC AZEK deck lumber.
I had researched the options and found that the "composites" used pulp wood which would mildew and rot, sometimes causing failure.
Had to order the AZEK from a local deck lumber store and paid about $180, including shipping for enough to do everything plus some for mistakes.
I don't think it's a good idea to try the Timbertech or Trex "composite" products for this application for the reason that merlinuxo just said.
The Azek could be a good choice but there are some compromises that you should be aware of. If you want the deck product with the wood grain, you'll only get the wood grain on one side and the edges. The back side is shiny. So for a handrail, you'll have 2 different surfaces; plus, when you cut or shape the edges, you will have a third texture on the edges, which isn't exactly smooth and it also doesn't resemble wood.
I used Azek for the rails of the coach roof and hatch board and am moderately pleased with the look (but I'm not that picky). That's because the shiny surface and the shaped surfaces are basically out of view. The wood grain that is exposed doesn't look too bad, but I found that compounding material and wax doesn't come off easily so I already have some whitish stains that I live with. (The rosewood color that I chose does look very nice, but it is dull ... not like varnished or oiled wood).
I'm happy with my application and I would use it the same way Sumner did for his ladder steps (actually a very nice application!). But I thought about using it for the hand rails and decided against it. One thing that shows up when you shape the boards are little voids that are inside the product. When you shape the material, it is hit or miss with regard to exposing these voids. They are not like bubbles, but more like long thin slits in the interior (about the thickness of a playing card). You definitely don't want them exposed on the top edge; although, I suppose you can fill them with something. Mostly, I didn't accept the look of the shaped edge and the shiny backside surface. You should know that Azek can be shaped like wood, but these products are intended to be used in the dimension they come in, only with end cuts or miter cuts, because the cut surfaces don't resemble the finished surfaces. It's not like wood in this regard, where all cuts can be made to look beautiful.
Also, Lowes refuses to cut, not because of the blades, it's because the product is expensive and they don't want customers coming back with boards that didn't fit and blaming it on Lowes. I had the same issue because I bought 12' lengths and didn't want to have them flopping on the top of the car on the way home. The customer service people said 'no way' but when I went in the back, a nice young guy listened to my explanation (he told me why they typically don't cut) and cut them to the length dimension that I needed to fit inside the car (basically in half). I doubt they would rip it for you, because of the concern expressed above.
I thought that I would live with the rails for a season or 2 before deciding if I want to replace handrails with plasteak or real teak. I decided to refinish the old ones for the time being.
:cry:.
