Picket Fence Material

[Alex Horvath]

Hi,
I'm an experienced woodworker planning a painted picket fence. It will be small scale with no more than 6' post spacing, between 3 or 4' tall. I'm planning boxed 4x4 posts with the 2"x2" pyramid pickets with dual 1"x4" rails sandwiching the pickets. Walpole calls this Westchester.



Material -

I wanted to do the whole fence in Azek however Azek rails sag. I could easily support the fence mid span with a small concrete pier with bracket (I will have a kickboard) but even the Azek salesman was a bit skeptical. I will probably use the pre-made Azek post boxes, a bit pricey but will save time and it's the posts that take most of the abuse. The rest would then be redwood if Azek is not possible. I have used the marine epoxy treatment on wood before. Very pricey though so I'll have to calculate the cost. It seems that Azek S4S is about the same as select heart redwood.

Are the Azek rails not advised under any circumstances?
Perhaps even with pier supports the rails would lean over time?
Walpole says they offer Azek fences but they don't provide details on line. I don't like the molded plastic fences - I can spot those 50' away.

Joinery - I assume the best way to attach the 1"x4" rails to the posts is mortise and tenon but this is time consuming. Would pocket screws work (using a longer exterior grade screw of course) or is there some other method? For construction grade fences I use the Simpson fence brackets but those are for 2"x4" and they don't look so good.

Curved section - I will have 2 sections with gentle curves (~20' radius). I have done a redwood arch using short pieces laminated together - then bandsaw the arch from this. Can curved rails be done the same way, i.e. glue pieces of 1"x or 2"x together vertically until you have the radius you want then bandsaw out the desired 1"x 4" ? Azek has an advantage here as it can be heated and formed at will.

Thanks

[Jim Becker]

If you're inclined to use a "non-wood" material, in addition to the potential issue you describe with sagging, you also need to pay attention to movement (shrink/expand) that's common with this type of material. Azek has a lot of shrink/expand with temperature changes and the general contractor who did our addition (a good friend now) told me recently that he stopped using it on projects. He's moved to another synthetic material, which I cannot name, that has substantially less expansion with increase temps. It's cut his call-backs considerably. A fence has a bit more flexibility (no pun intended) in this respect, but it's still something to consider.

I would likely not use pocket screws for a fence if you want the rails between the posts rather than fastened to the face. M&T allows for expansion/contraction with changing conditions.

[Rich Riddle]

I use Azek and other materials on a regular basis but get a bit silly and use white oak for support.

[Alex Horvath]

The main reason I looked at Azek is Walpole says they make fences from Azek solid vinyl. Perhaps they have some secret sauce though.
I know the Azek deck rail packages have a metal support in the bottom rail and they still require a support every 4' or so I don't see how Walpole is doing this but it would not surprise me if they have a metal support embedded in it or some thing to that effect. They sell Azek post caps so Azek may make special parts for them.