Pulling Posts (Fence, not Blog)
Pulling Posts (Fence, not Blog)
The previous owner of our property ran a dog boarding business and as part of his setup, he built a nice fenced-in area behind the house. It's a livestock-style wire fence with large wooden posts — some are eight inches in diameter — sunk deep into the ground. Since I'm not running a dog boarding business, I don't really need (nor do I want) this fence. I'd rather open things up to give the property a more free-flowing feel. But how do I go about pulling these posts, each of which may weigh 50 pounds or more and are sunk three to four feet into the ground? Physics to the rescue.
The first challenge is simply removing the fencing from the posts. Each post has probably eight to 10 heavy-duty staples holding the fence tight. I tried various methods of pulling them out and eventually settled on a good-quality nail puller and a heavy-duty engineering hammer. It usually doesn't take more than a couple of solid whacks and pry action to free each staple. The biggest difficulty is getting the staples at the bottom of the post, as I have to get down on my knees and maneuver around the ground.
In order to get the posts out of the ground, though, I knew I couldn't just use my legendary strength and pull them free through brute force. These posts are like telephone poles and they were sunk deep into the earth.
No, what I needed was leverage.
To achieve that, I would need to use a jack to lift the posts. But the posts being cylinders, there was nothing for a jack to grab on to. What I needed was some kind of ledge or handle the jack could grab.
My solution was to drill a ¾" hole through the post about a foot off the ground using a rather impressive 17-½" auger bit. Then I ran a threaded rod through the hole and a 2x6 block, tightening the rod down with washers and nuts. Then I drilled a second hole through the block and post and secured it with a second threaded rod and nuts.
This now-attached block essentially gave me the needed handle with which I could apply leverage.
With the block attached, it was time to break out the 48" farm jack, which may be one of my favorite tools.
I set the farm jack next to the post and started ratcheting it upwards. Quickly, the jack's lower jaw grabbed the bottom of the block. As I continued ratcheting, I could see the post slowly start to lift.
Then it stopped. I ratcheted some more, but the post didn't move one bit. WTF? Then I realized the problem. Instead of lifting the post, the farm jack was pushing itself deeper into the ground. This was because the foot of the jack was little larger than an index card and thanks to that small surface area and the pressure of the jack being concentrated on it, the jack was sinking itself rather than lifting the post.
To fix this problem, I turned once again to physics. I lowered the jack and placed a three-foot 2x8 board under its base. This would allow the downward force be more evenly and broadly distributed instead of being focused in one small area. The same concept is what allows a polar bear to walk on thin ice despite being so heavy; big paws distribute the bear's weight across a larger area. Put a polar bear in high heels (I dare you) and it will go right through the ice — assuming we haven't melted all the polar ice already thanks to global warming.
Anyway, with the board in place, I cranked the jack and immediately saw results. Slowly the post emerged from the earth like some sort of alien creature giving birth. In short order, it was fully lifted, which allowed me to pull it out of the hole, remove the block, and lay the post on the ground.
Of course, now there's a 4-foot hole in the ground, which would be a perfect booby trap if I was worried about an invading force. But for us, having the land pock-marked with leg-breaking death traps isn't so ideal. So I backfilled the hole with mulch and celebrated my victory.
It's a short-lived celebration, though, as I still have another 100-plus posts to remove. All in due time.
