[TowerTalk] Concrete for tower base

[Art Greenberg]

I'm putting up a tower soon, and I have questions about working with concrete.

The tower will the a Tashjian WT-51.

The hole is 2.5ft x 2.5ft, 5.5ft deep and the concrete extends 6 inches above grade for a total foundation height of 6ft. The instructions for the tower base call for it to be suspended in the hole while the concrete is poured. The instructions show a form around the top of the hole and additional lumber is used to suspend the base, sitting on top of the form. The concrete is to be poured to level with the top of the form, which means its just touching the underside of the lumber used to suspend the base. So the presence of the lumber suspending the base in the hole will be in the way of fully finishing the top of the concrete.

(a) How long do I have before the top surface of the pour cures too much to permit fully working the finish?

(b) How long should I allow the concrete to cure before I remove the lumber suspending the tower base?

Thanks.

-- 
Art Greenberg
art at artg.tv