[TowerTalk] New Tower Construction - Questions

[K7LXC@aol.com]

In a message dated 08/30/2000 3:43:45 PM Pacific Daylight Time, N8NGA@one.net 
writes:

> Just look in their catalog, or call Rohn.  

    Calling Rohn is mostly a futile exercise - you get as good and faster 
info here on TowerTalk from knowledgeable folks. OTOH, EVERYONE should have a 
copy of the Rohn catalog; it's got a bunch of valuable information relating 
to specs, hardware, etc. They're available from Champion Radio Products. 

> You should follow their recommendation.  

    Of course! It's the LXC Prime Directive. 

> The questions you asked don't get quite to the detail
>  you need.  For instance, you need to know what dia. of rebar is
>  required, the spacing, the method of tie, and how the rebar will be
>  integrated with the tower.  

    It's in the Rohn book. In many cases, the rebar isn't structural but is 
there to keep the concrete from shrinking and cracking. 

    BTW rebar sizes refer to eighths-of-an-inch; i.e. #4 rebar is 4/8 or 
1/2", #6 is 6/8 or 3/4".

> I normally do NOT recommend placing the tower itself in the cement.  

    Actually sinking a section in the base is pretty well accepted by most 
everyone. The bottom of the hole needs to have 4-6 inches of gravel in the 
bottom and the bottom of the section needs to rest on the gravel. This is for 
water condensation draining on the inside of the tower leg. Whether you use a 
10-foot section or the 5-foot short base is up to you. 

> Rohn sells a tower base, and it's used
>  with "J" bolts in the concrete.  By doing this, you have a way to
>  repair the tower without abandoning the base. The cage should be
>  suspended in the hole with wire to insure it's positioned properly
>  when the concrete is poured.  In the finished product, the cage
>  usually isn't any closer than 3" from an outside concrete surface, and
>  the cage is uniformly laid within the space, often on 12" centers.

    Instead of suspending it from above, you could also have it sitting on 
bricks, concrete garden stepping stones or anything made of concrete. As long 
as it doesn't touch the earth, that's all you need. 

Cheers,   Steve    K7LXC
Tower Tech 

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