Fake Azek columns

[dgbldr]

Say you are wrapping a bunch of 6x6 PT porch posts in Azek, 8 ft tall. HO wants some extra identical "columns" for looks. Do you:

a. Screw down some blocks top and bottom and build empty columns out of 4 Azek boards or
b. Any reason to put up a 6x6 or other wood structure first? .

[mike maines]

Re: Fake Azek columns

As long as you have blocks top and bottom (and maybe in the middle) I don't see why you would need any extra structure.

[Norm Yeager]

Re: Fake Azek columns

No reason at all for solid structure underneath. Our company did a condo job with 140 Azek columns. They had nothing underneath, only glued, pinned and mitered corners. Unfortunately the PM ordered the wrong length so we got to buy a second set. It worked out well for me as I got all the columns I wanted and have been using the pieces for everything from raised garden beds to siding, lattice, etc. They are very difficult to get apart and for most things the miter has to be ripped off but it's well worth the effort. The new columns went up and have been performing well for four years.

[Mark Parlee]

Re: Fake Azek columns

How big are the columns

We used a PVC column that was preformed and assembled around the post.

If you do attach it what happens if/when the post twists as 6x6 often do?

[dgbldr]

Re: Fake Azek columns

Mark, I assume a loaded 6x6 structural post fastened top and bottom will not twist greatly, that mostly happens on fence posts where the top is free to move. But I do worry a bit about warping and possibly cracking as it dries.

What would you do about it?

[Mark Parlee]

Re: Fake Azek columns

Is the post already in place or are you installing that as well?
If you are installing the post I recommend not using a 6x6 but using three 2x6's and one 5/4 piece. when you nail these together you can alternate the way you orient the grain and make it work in opposition to minimize movement.
The columns in my picture have a bearing post at the center and that is the way I fabricated the post. More time consuming but stable.

[Bill Robinson]

Re: Fake Azek columns

On the issue of posts and beams twisting one part of the solution is to use FOHC material.
While it is more spendy it is much less likely to twist and turn.

[dgbldr]

Re: Fake Azek columns

The posts are already in place so I have no say on that.

As to making a 6x6 out of multiple 2x6s, that's a bit iffy.

Some inspectors won't pass it without engineering, because 3 2x6s are OK but the 5/4 PT is deck facing, not structural rated lumber AND you need a fastening schedule specified.

[Mark Parlee]

Re: Fake Azek columns

the 5/4 is just facing to fur out the 4-1/2" face to 5-1/2" you don't need to consider the 5/4
what are you holding up that needs a 6x6

The bearing capacity of 3 2x6's is 22,860#
6x6 26,137#

these are fast calculations and subject to slight adjustment

[dgbldr]

Re: Fake Azek columns

Mark, I haven't ever done this multi-ply method, we're just talking hypothetical.

As I said, at the very least, it would fail because it's not a prescriptive method, so it needs engineering. Translation: the inspector would say to me "show me why the nailing schedule you have here is correct and appropriate". Without the correct nailing (or bolting), 3 pcs of 2x6 are worth no more than ONE piece of 2x6.

[charles]

Re: Fake Azek columns

On the issue of posts and beams twisting one part of the solution is to use FOHC material.
While it is more spendy it is much less likely to twist and turn.

Never heard of it. Is this readily available in your area? What about mine? Is the result any different than picking through a pile of posts to find ones without heart center? Why do hearts twist more than off-center sawn?

[Bill Robinson]

Re: Fake Azek columns

Don't know the science of twisting, just know it is true.

No different than picking, in fact, if you order FOHC they will cost more than picking

You should be able to order FOHC at any lumber yard.

[Norm Yeager]

Re: Fake Azek columns

Mark, I assume a loaded 6x6 structural post fastened top and bottom will not twist greatly, that mostly happens on fence posts where the top is free to move. But I do worry a bit about warping and possibly cracking as it dries.

What would you do about it?

In my experience, very true. The twisting will be controlled by the fastened ends , but buckling and warping is still a real possibility, especially if the structural columns are SYP. I don't believe the Azek will hold the force of a 6x6 wet post that wants to move. I've seen it first hand. If fir or cedar would meet the structural requirements they would be my material of choice.

[Mark Parlee]

Re: Fake Azek columns

Here is a great pic of some bowed posts.

completely different than we are discussing but a good example of what not to do

[Joe Adams]

Re: Fake Azek columns

We use engineered posts to minimize problems with wood movement. Just be sure to elevate them on a post base, prime the ends (if not the whole thing), and wrap them in a good WRB (like Super Jumbo Tex 60) before attaching the Azek.