How high can I build using concrete forms

[kelasings]

Hello,

I have a concrete question. I intended to use concrete footings and concrete tube forms to build posts and then use wood connected to the concrete with metal anchors above ground. Then I thought why can't I just make the concrete as high as I need it to be using the concrete forms and cut out the wood posts all together. I could rest the wood beams for the floor directly on top of the concrete using metal anchors. My question is how high can you safely make a concrete pier (using a tube) to use as a foundation? I have been searching the net trying to find information on it but all I've found is information on making the concrete footing and pier and then attaching wood to it above ground. Why can't the whole pier unit just be concrete?

Thanks in advance,

Kela

[Ryan B]

A few thoughts on tube forms in the 12" diameter range.
They cost more per foot that a 4x4 P.T. post.
Unless you have some of the form buried (1' or so) and the soil packed around the excavated hole you will need bracing for each form if it's more than 1' tall.
They can handle the load but they become slightly top-heavy and unstable at about this height.
If you have a bunch of forms that all need to be at the same elevation you should have adjustable post bases or shims as concrete has a tendency to settle as it cures. They taller they are the more they settle. The phrase "I will get it close but it won't be exact" comes to mind!

I have used 12" forms up to 8' – much bracing involved in this application.
I often use short forms in sandy soil where a nice round hole is impossible to dig and the concrete to fill the hole is too costly. They also work in rocky unconsolidated soil for the same reason.

If your site is level a ribbon footing and ribbon wall is a more value oriented choice