[TowerTalk] concrete base for Rohn 140 foot SSV

[Steve Maki]

I general, shallow pad foundations require the most concrete - they are 
basically *weight* foundations. Designs which go the deepest use the 
least because they have friction against the earth working in their 
favor. OTOH, there is usually more labor cost in a deep foundation.

If you don't get a soil study and custom engineered design, use the 
money you save by not scrimping on concrete. A 140' SSV deserves it.

-Steve K8LX


On 1/15/2011 3:25 PM, Marvin Gorden wrote:
> Looking at the Rohn base specs, I am quite surprised at the requirements,
> assuming I read it right.  For a base, without piers, the specs call for a
> 14'-3" X 14'-3" X 4' concrete base ( 30.1 cubic yards).
>
> To me that seems like considerable over kill.
>
> My tower has 8N, 7N, 6N, 5N, 4N, 3WN and 2W sections.
>
> I looked at a 140' SSV installation a few miles away from here and that base
> is 7'-9" square.  I don't know if that sets on piers or how deep it maybe.
>
> Any qualified comments would be appreciated, before I start digging.