Advice for installing wooden posts

[Cordata]

Hi all,

 

I have been offering services planting fairly big trees for a while now and I have one coming up where I need to plant two large birch trees, size class 18/20.

 

The person at the nursery recommended getting 8 foot posts as the standard smaller wooden stakes won't be tall enough to support the trees once driven into the ground.

 

I've planted large trees for this customer before and had so much grief getting the posts in, it was stony the further I dug down. I used a post knocker like this: 

 

 

, and couldn't hit the posts hard enough to drive them as far as I'd like. Even hitting full force with that wasn't doing much. Thankfully they've held +1 year later, can be shoogled a bit but it worked.

 

I want to do a proper job this time but need to take a different approach so the posts are definitely solid, some suggestions online say use a steel bar like this:

to make a kind of pilot hole. Others say use a big post knocking hammer, I could probably hit with more force using that.. any tips for getting them in the ground, how you approach it if ground conditions are tricky?

[scbk]

Pilot hole with a pinch bar then drive the posts in. You can get more force with a mell (big hammer) than a 2 handed post knocker but on 8ft posts you would need to be on quite a high step to reach. (feet about 2/3ft off the ground)

 

If you've not used a mell before, you really need to practice first to not make a pigs ear of the top of the post

 

Using the 2 handed post knocker above shoulder height I would recommend wearing a hard hat. I had one come off the top of an 8ft post once and hit me on the head, that was a really bad day 

[Cordata]

6 minutes ago, scbk said:

Pilot hole with a pinch bar then drive the posts in. You can get more force with a mell (big hammer) than a 2 handed post knocker but on 8ft posts you would need to be on quite a high step to reach. (feet about 2/3ft off the ground)

 

If you've not used a mell before, you really need to practice first to not make a pigs ear of the top of the post

 

Using the 2 handed post knocker above shoulder height I would recommend wearing a hard hat. I had one come off the top of an 8ft post once and hit me on the head, that was a really bad day 

 

Thanks appreciate the advice.

 

Practically how do you use the pinch bar, just hit the ground with arm strength or hammer it in? And just the pinch bar's diameter in the ground will do, or I should try to make a sizable hole with it?

 

I looked up those hammer/mell things and lots of options, don't know which head weight is best-

 

• 4.5kg screwfix one 

  ERROR: The request could not be satisfied

  WWW.SCREWFIX.COM
• 5.4kg one with wooden handle 

  Access Denied

  WWW.ZORO.CO.UK
• 6.4kg bulldog one, imagine it gets tiring quick but I like that brand, makes quality stuff 

  Bulldog Fencing Mauls 6.4kg

  WWW.SAM-TURNER.CO.UK

  ---

  Features: One piece 36" heavy-duty fibreglass handle Epoxy paint coated cast head Soft-grip Head tempered for strength and rigidity

[Doug Tait]

I remember once digging a hole, or maybe it was driving in a post, and there wasn't a stone or root in the way, it was magnificent.

 

Plunge the pinch bar straight down in the ground where the middle of your post is going, do a widening, circular motion with the top and make the hole a cone shape, repeat and widen the cone, repeat, deeper and wider. Aiming to be a really tight fit for the post and it doesn't actually have to pierce the ground itself very much.

 

While using the pinch bar to make the hole you're also probing for stones, you can often push a stone aside with it or break through one. Don't hammer the pinch bar, just use it in your hands.

[kram]

For ease and lazyness I'd suggest an engine 2t auger with a drill to make a pilot hole of about 20mm smaller than the post you intend to knock in, that will make it very easy work. The bigger size drills may be useful for the larger planting holes too. I have one from doing fences, I enjoy using it and always looking for an excuse.

 

I've not heard the term "mell" before , is that northern for maul?

I use a scaff pole with a large lump of steel welded on the end, weighs about 8kg. Heavier is quicker.

[doobin]

You could always use three smaller posts as a tripod for more strength with less need to go deep.

 

Doesn't matter how big your maul/handheld post knocker is, if it's proper stony you're not getting them in to depth without digging hole first or using heavier machinery.

[woody paul]

So we are talking a 5m high tree, even a 8ft stake is not enough, would consider under ground anchor system. Or 3 guy wire system. 

[manco]

word of warning, too many posts could cause a fence

[andy ellis]

i agree with woody paul,use an under ground anchor system much easier and then your not looking at an ugly post either

[Cordata]

I've heard of these underground anchors but never used any yet.. Just checked the price and if I'm not mistaken it's around £80 per tree I'd need to spend which is prohibitive for what I've priced already.

 

The 8ft posts (if I can secure them properly in the ground) I'm sure will be more than enough, it's not an exposed garden, it's surrounded by a tall hedge and buildings.