Rough Guestimate of # of fence posts needed?

TSYORK · #1 04/19/10, 10:27 AM

This is a cross-post from General Homesteading:

I'm getting ready to fence in a grass pasture to put a few head of calves on. The pasture is a rectangle, roughly 6 acres. There really won't be any cut around, etc. I'm going to have my post punched, but I'm trying to figure out how many I roughly need to purchase. My post are being put every 20 feet. Can anyone give me a in the ballpark calculation on how many I will need to do this?

TIA

Farm 36 · #2 04/19/10, 10:49 AM

I would mark 20 ft on the ground and pace that off by walking to find how many steps to walk 20 ft . Take a piece of paper and walk the line for the fence and tally the post that you need . Remeber that all valleys of the hills and the top of the hills need a post

TSYORK · #3 04/19/10, 10:52 AM

It's pretty dang level, although there's some slope on the back side of the pasture.

sassafras manor · #4 04/19/10, 12:09 PM

A quick & easy way is to multiply the # of acres by number of sq. ft. per acre. That will give you approx. 250,000 sq. ft. which is equivilent to a 500' by 500' area. Any way you lay out the area, as a square or rectangle the number of linear feet will be the same. So basically there will be 2000 linear feet of fence and with the posts every 20' you will need approx. 100 t-posts. I hope this helps.

TSYORK · #5 04/19/10, 01:39 PM

Quote:

Originally Posted by sassafras manor

A quick & easy way is to multiply the # of acres by number of sq. ft. per acre. That will give you approx. 250,000 sq. ft. which is equivilent to a 500' by 500' area. Any way you lay out the area, as a square or rectangle the number of linear feet will be the same. So basically there will be 2000 linear feet of fence and with the posts every 20' you will need approx. 100 t-posts. I hope this helps.

Thanks!!!

It's been a LONG time since Algebra and Geometry, so I was a little rusty on my calculations. I came up with roughly a hundred as well, but I wanted me make sure I wasn't short shooting my projections.

trbizwiz · #6 04/19/10, 04:07 PM

If you are going barbed wire you wont be happy with post spaced 20 feet. If you are going high tensile electric, and if your land is fairly flat which it sounds as though it is, 30 to 50 feet will be adequate. Also with electric fence I would recommend something like the powerflex composite posts. They drive easily, they dont conduct electricity so there is no need for insulators (which fail). THey are a little pricey, but with the added distance needed between them they work out to be cheaper. Plus they should last forever, they wont rust or rot.
I personally use them on 35 foot spacing on my 5 strand perimeter that compensates for any elevation change. And my interior cross fence I space them at 50 feet, except on 2 lines where I ran out of posts (I used 2 as gates, I did not mis figure), and I have a 100 foot spacing in one area on 2 cross fences. I use gripples so I don't keep my HT wire overly tight, but I don't have much sag either. I did use powerflex's NZ wire, I have no idea if that makes any difference (I bought it because it should last longer with out rusting or corroding).
I am very happy with the aesthetics and function of my fencing, and saving money is always nice.
Good luck on your project.

TSYORK · #7 04/19/10, 05:14 PM

The fence will be high tensile electric, and the land is pretty flat. The post will be drive by a hydraulic punch, used on an Oliver 100 hp tractor.

agmantoo · #8 04/19/10, 09:21 PM

A square fenced area and a rectangular fenced area containing the same square footage will not take the same number of posts!

trbizwiz · #9 04/20/10, 02:52 PM

I dont know what your soil is like. Mine is a pretty sweet mix. But I easily drove my powerflex posts by hand with a hand T post driver. Do it after a rain, right now going on 18 days no rain might be a chore for me anyway.
Now the next time I do a corner post, i'd love to use the hydrolic post driver, My corner posts werent hard to get in the ground, but seems like a driven post would give you fewer problems when the ground gets soft and wet.
As to the number of posts, I saw once a satellite photo program that would allow you to find your property and then you could drop pins in the corners and it would give you dimensions. I dont remember where I saw it but I would guess a quick google search would pull one up. Also you county court house should have a sat photo with linear feet on file. they will even print it off for you for free (at least in my county they do) if you are the land owner, small fee if your not.