[TowerTalk] FW: Concrete Pad for U.S. Tower TX-472

[Patrick Greenlee]

My next tower install is coming late this summer or early fall 
(depending on when the tower is built/shipped.  I fully expect the hole 
4x4x8 ft to at least partially fill up from ground water if I don't take 
precautions.  Even during the recent record setting drought I had ground 
water within 5 ft of the surface but this is NOT a drought year.

Boat launching ramps are poured into forms fully submerged as concrete 
easily displaces the water without being "watered down." My concern is 
that the walls of the hole, if significantly soaked, may collapse. So I 
may put a sump pump in the hole with a float switch to keep the water 
pumped down to a couple inches.  I'll build a little cubical wood frame 
and cover it with geotextile to filter out solids and not let the pump clog.

Patrick     NJ5G

On 7/25/2015 11:14 PM, Roger (K8RI) on TT wrote:
> I had no problem keeping it wet.  The spring water table was just a 
> couple inches below the surface. We kept a sump pump running until the 
> concrete was being poured into the hole.   It was a good dry mix 
> relatively speaking, yet when the concrete reached the top, it was 
> pushing out water.
>
> As I was breaking up the over flow a couple weeks later, someone 
> asked, "Wouldn't it be easier to just paint it green?"  The dirt under 
> the hardened overflow was still soggy.  So other than sprinkling the 
> surface, keeping it wet was not a problem<:-)
>
> 73
>
> Roger (K8RI)
>