Fencing tricks for hole depth?

[MNBobcat]

Hi Guys,

I'm setting 12 foot treated posts 4 feet into the ground on the outside perimeter of a couple acre field. In the past, I've used a tape measure to mark the posts with marking paint and then dropped them in the hole and lined the paint mark up with the ground level. Using that technique, I found that my posts might vary in height 4 - 5 inches or more. A lot I think has to do with that you usually have a pile of dirt around the hole which makes it difficult to determine the level of the prevailing ground. Stretching a string won't work on ground not perfectly flat.

Any tips for getting the post height to be more consistent or is what I'm seeing just how it goes?

 

[bcp]

I once saw a fence company set posts to the approximate depth, build the fence, then trim the post tops to make them even.

Bruce

 

[MBTRAC]

With your post all cut to the same length it comes down to having a consistent post hole depth:

- we use a depth markings on the auger drive shaft & limit the hydraulic cylinder travel our pcitured rig (same principles apply with a standard 3pl PTO PHD or Hyd Auger unit ).
- As an alternative & as much speedier method of fencing, where ever practical our preference is to use a post driver - again limiting the driver hammer stroke to the desired depth for consistent post height.
- If the post holes are already in the ground & you're trying to correct/eliminate a height variance prior to setting the posts, clear any loose dirt pile from around the post hole, measure the hole depth to the undisturbed/original ground & set/adjust the depth so it's consistent in all holes.
- Or as BCP advises lop the posts to even up ......though the wire runs need be spot on & the post needs enough "surplus" for this to work.

Personally, there's something that drives me crazy about fencing which is neither straight nor level - I'd much rather take a little longer & adjust to get it right than live with consequences of a "near enough" job for years (our farmhands I sure will endorse how pedantic I am on this task)

 

[ericher69]

I once saw a fence company set posts to the approximate depth, build the fence, then trim the post tops to make them even.

Bruce

Set posts

Rotary laser level, mark then cut tops

 

[DT86]

How does a laser level work on uneven ground?

 

[paddockbasha]

I have used what my Dad called a "bunyip" level. (only Australians will understand that). It's a long length of clear plastic tube with water in it. Tape each end to a tomato stake so you can keep the ends upright and not let the water run out. If setting 12 foot posts in 4 foot holes, mark posts at, say, 6 feet down from top. Then run the plastic tube between the last post and the one you are setting and make sure the distance between the water level in the tube and the 6 ft marks on the last post and the one you are setting is the same. That gets everything level if that's what you are after.

 

[Brad_Blazer]

I think what most of us go for is posts that follow the terrain at a constant height. I mark my auger and have someone move the dirt away from one side of the hole to see where ground level is. My goats aren't real picky. You could have someone hold a marked stick next to the hole just outside the dirt pile to get a reference for where you want the auger head to stop. If you use a hand post hole digger to clean out the hole you can apply the same principals for consistent depth.

Of course, if you have a sweet drill rig like MBTRAC there's no excuse for not having a beautiful fence line.

 

[jinman]

If you use a hand post hole digger to clean out the hole you can apply the same principals for consistent depth.

That's exactly what I do to get it as close as possible. Mark the 4' on the handles of the hand digger used to clean out the holes. Probe the loose dirt to find the native dirt and use that level as a gage. If you are building a fence, post height varies with ground elevation, but if you are building a structure, then you'll have to come back and trim the posts. You'll waste way too much time trying to make them all the same by hole depth.

 

[SuperCobra]

Depending on how uneven your ground is and what type of fence you are building, I think it looks better to have the top boards (and therefore the tops of the posts) all on a line and not going up and down with the contour of the land. You can get the average by setting the first post and last post and running a string tight between the two. If there are huge dips or hills, set a few posts in between on those and run the string to them. You can then use the hand held post hole digger to dig each hole to the depth needed to get the top of the posts to the same position relative to the string. However, you're setting your posts to 4' deep and I've never seen and hand held post hole digger work that deep.

I've heard this before but now I've seen it first hand: if you cut the tops off pressure treated posts you are exposing the inside of the wood (not pressure treated) and they will rot out a lot faster than the uncut portion in the ground. This is happening to me after just six years. I've seen products advertised that you paint on to protect end cuts (Copper-Green is one) but I haven't tried them or seen them locally for sale.

 

[Midniteoyl]

Coat hanger/similar stiff metal stapled on at the four foot mark. Clear enough dirt to see hanger resting on ground...

In fact, I bet you could rig something up outta rebar that is removable/movable to each post. Slip on, tighten at 4 foot, set post in hole, hang by rebar, fill hole/shim/concrete/whatever, remove and move to next pole...