[TowerTalk] BASE REBAR and Lightning

[Jim Lux]

W0UN -- John Brosnahan wrote:
>>> Here's my question. (Im learning disabled...etc..etc.)
>>>
>>> What about guys that use a piece of rohn 25 as the base, stick
>>> the end in the 6 inches of gravel, and then fill up the rest
>>> with concrete. There is no 4 inches of insulation with the earth
>>> there, because the gravel has gaps  and moisture in it
>>> which connect with the earth anyway. (a chemical fact)
>> Those guys aren't following standard concrete practice (avoiding things
>> sticking through the concrete/soil interface)
> 
> But letting the tower leg condensation DRAIN is more important.   And 
> technically
> the tower should not be relied upon for structural reinforcing of the concrete.
> 
> Nothing is more scary than to see tower legs split open at the concrete
> base due to freeze cracking.  EXCEPT for not knowing if the legs are almost
> rusted through because no drainage was provided.
> 
> It is absolutely mandatory to let the legs DRAIN out the bottom of the
> concrete base.
> 
> --John  W0UN
>
I agree about the drainage issue.

It also occurred to me that the tower section sticking out is 
(hopefully) galvanized, which would make a difference.