[TheForge] setting fence posts

[terry l. ridder]

hello bruce;


On Sun, 24 May 2009, Bruce Freeman wrote:

> I calculate you're digging 12" holes, 9" in diameter.
>

9 inch diameter hole 48 inches deep. this is a dekalb county illinois
rule. i am zoned agriculture and they still say that since it is a chain
link fence and not a field fence that i have to sink the posts 48
inches. i am trying to get them to allow a variance of only digging 36
inches deep. a 6-inch diameter hole would be less expensive on the
cement. that is yet another variance being asked for.

i have had wood post field fences last with just the wood post pounded
into the ground for 3ft. i do not understand county building rules and
regulations. basically, just a way to produce revenue.

48 inches is considered to be the frost depth for dekalb county
illinois.

1 cubic foot is equal to 1728 cubic inches.

( 48 * 9 * 9 * pi / 4 ) / ( 1728 ) = 1.767145868 cubic ft.
( 36 * 9 * 9 * pi / 4 ) / ( 1728 ) = 1.325359401 cubic ft.

( 48 * 6 * 6 * pi / 4 ) / ( 1728 ) = 0.785398163 cubic ft.
( 36 * 6 * 6 * pi / 4 ) / ( 1728 ) = 0.589048623 cubic ft.

1.767145868 cubic ft * 50 = 88.36 cubic ft.
1.325359401 cubic ft * 50 = 66.27 cubic ft.
0.785398163 cubic ft * 50 = 39.27 cubic ft.
0.589048623 cubic ft * 50 = 29.45 cubic ft.

>
> I can't help thinking how much better off you'd be to dig deeper and
> narrower.  Rule of thumb is 1/3 the post should be in the ground - and
> then you don't need the concrete at all (but local conditions may
> vary).
>
> Alternatively, just dig narrower.  Any chance of getting a smaller
> auger?  If you can swing it, it might be cheaper to make your own
> auger.  The blades on the bottom need be sturdy, but the screw needs
> only be strong enough to lift the earth out of the hole.  I'd envision
> a stout rod as the axis with a couple bands spiraled up around it and
> tack welded in place, or maybe to some cross-supports like skewers
> through a BBQ spit.  Might could make something that attaches to the
> existing 9" auger, but bores a hole only 4" or so in dia. x 12" deep.
>

looking at making a 6 inch auger. they are basically 2-inch pipe with
1/16 inch thick flat mild steel tack welded to it in a simple helix. the
tip is where the is some heavy duty steel.

>
> That would reduce your concrete usage to about 1/4 cuft per hole x 50
> holes = 12 cuft.
>
> On Sun, May 24, 2009 at 8:26 AM, terry l. ridder <terrylr at blauedonau.com> wrote:
>> hello;
>>
>> i have received my county permit to build my fence. i am looking at the
>> various cement mixtures offered by quikcrete and others and do not get a
>> good feel for just how many 40/80 lbs bags would be needed per fence
>> post. i am using a 3-pt hitch post hole digger with a 9inch auger. the
>> fence posts are 2 inch galvanized pipe. basically each hole is roughly
>> 1.76 cubic feet. the pipe does take up some space but it is small
>> compared to the hole. the fence is 400 ft long with a fence post every 8
>> ft. roughly 50 fence post. so roughly 1.78 cubic feet x 50 gives 88
>> cubic feet of cement is needed. what is the least expensive why to make
>> up the necessary cement mixture for setting fence posts?
>>
>>
>>
>> --
>> terry l. ridder ><>
>

-- 
terry l. ridder ><>